Skip to content

Latest commit

 

History

History
executable file
·
4086 lines (3032 loc) · 129 KB

API.md

File metadata and controls

executable file
·
4086 lines (3032 loc) · 129 KB
Raw

16.0.0-rc1 API Reference

Joi

version

Property showing the current version of joi being used.

validate(value, schema, [options], [callback])

Validates a value using the given schema and options where:

  • value - the value being validated.
  • schema - the validation schema. Can be a joi type object or a plain object where every key is assigned a joi type object using Joi.compile (be careful of the cost of compiling repeatedly the same schemas).
  • options - an optional object with the following optional keys:
    • abortEarly - when true, stops validation on the first error, otherwise returns all the errors found. Defaults to true.
    • allowUnknown - when true, allows object to contain unknown keys which are ignored. Defaults to false.
    • context - provides an external data set to be used in references. Can only be set as an external option to validate() and not using any.prefs().
    • convert - when true, attempts to cast values to the required types (e.g. a string to a number). Defaults to true.
    • error - error formatting settings:
      • dateFormat - sets the string format used when including dates in error messages. Options are:
        • 'date' - date string.
        • 'iso' - date time ISO string. This is the default.
        • 'string' - JS default date time string.
        • 'time' - time string.
        • 'utc' - UTC date time string.
      • escapeHtml - when true, error message templates will escape special characters to HTML entities, for security purposes. Defaults to false.
      • language - the prefered language code for error messages. The value is matched against keys are the root of the messages object, and then the error code as a child key of that.
      • wrapArrays - if true, array values in error messages are wrapped in []. Defaults to true.
    • messages - overrides individual error messages. Defaults to no override ({}). Messages use the same rules as templates. Variables in double braces {{var}} are HTML escaped if the option errors.escapeHtml is set to true.
    • noDefaults - when true, do not apply default values. Defaults to false.
    • nonEnumerables - when true, inputs are shallow cloned to include non-enumerables properties. Defaults to false.
    • presence - sets the default presence requirements. Supported modes: 'optional', 'required', and 'forbidden'. Defaults to 'optional'.
    • skipFunctions - when true, ignores unknown keys with a function value. Defaults to false.
    • stripUnknown - remove unknown elements from objects and arrays. Defaults to false.
      • when an object :
        • arrays - set to true to remove unknown items from arrays.
        • objects - set to true to remove unknown keys from objects.
      • when true, it is equivalent to having { arrays: false, objects: true }.
  • callback - the optional synchronous callback method using the signature function(err, value) where:
    • err - if validation failed, the error reason, otherwise null.
    • value - the validated value with any type conversions and other modifiers applied (the input is left unchanged). value can be incomplete if validation failed and abortEarly is true. If callback is not provided, then returns an object with error and value properties.

When used without a callback, this function returns a Promise-like object that can be used as a promise, or as a simple object like in the below examples.

const schema = {
    a: Joi.number()
};

const value = {
    a: '123'
};

Joi.validate(value, schema, (err, value) => { });
// err -> null
// value.a -> 123 (number, not string)

// or
const result = Joi.validate(value, schema);
// result.error -> null
// result.value -> { "a" : 123 }

// or
const promise = Joi.validate(value, schema);
promise.then((value) => {
    // value -> { "a" : 123 }
});

ValidationError

Thrown by assert when validation fails.

See Errors

compile(schema)

Converts literal schema definition to joi schema object (or returns the same back if already a joi schema object) where:

  • schema - the schema definition to compile.
const definition = ['key', 5, { a: true, b: [/^a/, 'boom'] }];
const schema = Joi.compile(definition);

// Same as:

const schema = Joi.alternatives().try([
    Joi.string().valid('key'),
    Joi.number().valid(5),
    Joi.object({
        a: Joi.boolean().valid(true),
        b: Joi.alternatives().try([
            Joi.string().regex(/^a/),
            Joi.string().valid('boom')
        ])
    })
]);

describe(schema)

Returns an object that represents the internal configuration of a joi schema. Useful for debugging and exposing a schema's configuration to other systems, like valid values in a user interface.

  • schema - the schema to describe.
const schema = Joi.any().valid([ 'foo', 'bar' ]);

console.log(Joi.describe(schema));

Results in:

{ type: 'any',
  flags: { allowOnly: true },
  valids: [ 'foo', 'bar' ] }

assert(value, schema, [message], [options])

Validates a value against a schema and throws if validation fails where:

  • value - the value to validate.
  • schema - the validation schema. Can be a joi type object or a plain object where every key is assigned a joi type object using Joi.compile (be careful of the cost of compiling repeatedly the same schemas).
  • message - optional message string prefix added in front of the error message. may also be an Error object.
  • options - optional options object, passed in to Joi.validate
Joi.assert('x', Joi.number());

attempt(value, schema, [message], [options])

Validates a value against a schema, returns valid object, and throws if validation fails where:

  • value - the value to validate.
  • schema - the validation schema. Can be a joi type object or a plain object where every key is assigned a joi type object using Joi.compile (be careful of the cost of compiling repeatedly the same schemas).
  • message - optional message string prefix added in front of the error message. may also be an Error object.
  • options - optional options object, passed in to Joi.validate
Joi.attempt('x', Joi.number()); // throws error
const result = Joi.attempt('4', Joi.number()); // result -> 4

ref(key, [options])

Generates a reference to the value of the named key. References are resolved at validation time and in order of dependency so that if one key validation depends on another, the dependent key is validated second after the reference is validated.

References support the following arguments:

  • key - the reference target. References can point to sibling keys (a.b) or ancestor keys (...a.b) using the . separator. If a key starts with $ is signifies a context reference which is looked up in the context option object. The key can start with one or more separator characters to indicate a relative starting point.
  • options - optional settings:
    • adjust - a function with the signature function(value) where value is the resolved reference value and the return value is the adjusted value to use. For example (value) => value + 5 will add 5 to the resolved value. Note that the adjust feature will not perform any type validation on the adjusted value and it must match the value expected by the rule it is used in. Cannot be used with map.
    • map - an array of array pairs using the format [[key, value], [key, value]] used to maps the resolved reference value to another value. If the resolved value is not in the map, it is returned as-is. Cannot be used with adjust.
    • prefix - overrides default prefix characters for:
      • global - references to the globally provided context preference. Defaults to '$'.
      • local - references to error-specific or rule specific context. Defaults to '#'.
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
    • ancestor - if set to a number, sets the reference relative starting point. Cannot be combined with separator prefix characters. Defaults to the reference key prefix (or 1 if none present).

Note that references can only be used where explicitly supported such as in valid() or invalid() rules. If upwards (parents) references are needed, use object.assert().

const schema = Joi.object({
    a: Joi.ref('b.c'),
    b: {
        c: Joi.any()
    },
    c: Joi.ref('$x')
});

Joi.validate({ a: 5, b: { c: 5 } }, schema, { context: { x: 5 } }, (err, value) => {});

Relative references

By default, a reference is relative to the parent of the current value (the reference key is lookup up inside the parent). This means that in the schema:

{
    x: {
        a: Joi.any(),
        b: {
            c: Joi.any(),
            d: Joi.ref('c')
        }
    },
    y: Joi.any()
}

The reference Joi.ref('c') points to c which is a sibling of d - the reference starting point is d's parent which is b. This schema means that d must be equal to c.

In order to reference a parent peer, you can use a separator prefix where (using . as separator):

  • . - self
  • .. - parent (same as no prefix)
  • ... - grandparent
  • .... - great-grandparent
  • etc.

For example:

{
    x: {
        a: Joi.any(),
        b: {
            c: Joi.any(),
            d: Joi.ref('c'),
            e: Joi.ref('...a'),
            f: Joi.ref('....y')
        }
    },
    y: Joi.any()
}

Another way to specify the relative starting point is using the ancestor option where:

  • 0 - self
  • 1 - parent (this is the default value if no key prefix is present)
  • 2 - grandparent
  • 3 - great-grandparent
  • etc.

For example:

{
    x: {
        a: Joi.any(),
        b: {
            c: Joi.any(),
            d: Joi.ref('c', { ancestor: 1 }),
            e: Joi.ref('a', { ancestor: 2 }),
            f: Joi.ref('y', { ancestor: 3 })
        }
    },
    y: Joi.any()
}

Note that if a reference tries to reach beyond the value root, validation fails.

isRef(ref)

Checks whether or not the provided argument is a reference. It's especially useful if you want to post-process error messages.

const ref = Joi.ref('a');
Joi.isRef(ref); // returns true

template(template, [options])

Generates a template from a string where:

  • template - the template string using the template syntax.
  • options - optional settings used when creating internal references. Supports the same options as ref().

Template syntax

The template syntax uses {} and {{}} enclosed variables to indicate that these values should be replace with the actual referenced values at rendering time. Single braces {} leave the value as-is, while double braces {{}} HTML-escape the result (unless the template is used for error messages and the errors.escapeHtml preference flag is set to false).

The variable names can have one of the following prefixes:

  • # - indicates the variable references a local context value. For example, in errors this is the error context, while in rename operations, it is the regular expression matching groups.
  • $ - indicates the variable references a global context value from the context preference object provided as an option to the validation function or set using any.prefs().
  • any other variable references a key within the current value being validated.

isSchema(schema)

Checks whether or not the provided argument is a joi schema.

const schema = Joi.any();
Joi.isSchema(schema); // returns true

reach(schema, path)

Get a sub-schema of an existing schema based on a path that can be either a string or an array of strings For string values path separator is a dot (.).

const schema = Joi.object({ foo: Joi.object({ bar: Joi.number() }) });
const number = Joi.reach(schema, 'foo.bar');

//or
const result = Joi.reach(schema, ['foo', 'bar']); //same as number

defaults(fn)

Creates a new joi instance that will apply defaults onto newly created schemas through the use of the fn function that takes exactly one argument, the schema being created.

The function must always return a schema, even if untransformed.

const defaultJoi = Joi.defaults((schema) => {

    switch (schema.schemaType) {
        case 'string':
            return schema.allow('');
        case 'object':
            return schema.min(1);
        default:
            return schema;
    }
});

const schema = defaultJoi.object(); // Equivalent to a Joi.object().min(1)

bind()

By default, some joi methods to function properly need to rely on the joi instance they are attached to because they use this internally. So Joi.string() works but if you extract the function from it and call string() it won't. bind() creates a new joi instance where all the functions relying on this are bound to the joi instance.

const { object, string } = require('@hapi/joi').bind();

const schema = object({
  property: string().min(4)
});

extend(extension)

Creates a new joi instance customized with the extension(s) you provide included.

It is important to understand that original joi library is not modified by this.

Terms

The extension makes use of some common structures that need to be described prior :

  • value - the value being processed by Joi.
  • state - an object containing the current context of validation.
    • key - the key of the current value.
    • path - the full path of the current value.
    • ancestors - an array of the potential parents of the current value.
    • flags - a reference to the schema's internal flags.
  • prefs - preferences object provided through any().prefs() or Joi.validate().

Extension

extension can be :

  • a single extension object
  • a factory function generating an extension object
  • or an array of those

Extension objects use the following parameters :

  • name - name of the new type you are defining, this can be an existing type. Required.
  • base - an existing joi schema to base your type upon. Defaults to Joi.any().
  • coerce - an optional function that runs before the base, usually serves when you want to coerce values of a different type than your base. It takes 3 arguments value, state and prefs.
  • pre - an optional function that runs first in the validation chain, usually serves when you need to cast values. It takes 3 arguments value, state and prefs.
  • messages - an optional object to add error definitions. Every key will be prefixed by the type name.
  • describe - an optional function taking the fully formed description to post-process it.
  • rules - an optional array of rules to add.
    • name - name of the new rule. Required.
    • params - an optional object containing joi schemas of each parameter ordered. You can also pass a single joi schema as long as it is a Joi.object(), of course some methods such as pattern or rename won't be useful or won't work at all in this given context.
    • setup - an optional function that takes an object with the provided parameters to allow for internals manipulation of the schema when a rule is set, you can optionally return a new joi schema that will be taken as the new schema instance. At least one of setup or validate must be provided.
    • validate - an optional function to validate values that takes 4 parameters params, value, state and prefs. At least one of setup or validate must be provided.
    • description - an optional string or function taking the parameters as argument to describe what the rule is doing.

Factory functions are advised if you intend to publish your extensions for others to use, because they are capable of using an extended joi being built, thus avoiding any erasure when using multiple extensions at the same time. See an example of a factory function in the section below.

The params of rules rely on the fact that all engines, even though not stated in the ECMA specifications, preserve the order of object keys, this is a conscious choice to simplify the API for the end-user. If you ever see an engine misbehaving or are uncomfortable relying on this, you can use a single option object to describe your parameters, like:

params: { options: Joi.object({ param1: Joi.number().required(), param2: Joi.string() }) }

To resolve referenced params in you validate or setup functions, you can use the following approach:

validate(params, value, state, prefs) {

    let {foo} = params;
    if (Joi.isRef(foo)) {
        foo = foo.resolve(value, state, prefs);
    }
  //...
}

Any of the coerce, pre and validate functions should use this.createError(code, value, local, state, prefs) to create and return errors. This function potentially takes 5 required arguments:

  • code - the dotted type of the error matching predefined messages or the ones defined in your extension.
  • value - the value responsible for the error.
  • local - a free-form object that can contain anything you want to provide context on regarding the error. This object's properties are inserted in the error message where bracketted placeholders are.
  • state - state that the validation was in, which contains the current key, path, parent if any, or reference if any. Usually you just have to pass the state you were given.
  • prefs - preferences that were used for the validation. Usually you just have to pass the prefs you were given.

npm note

If you publish your extension on npm, make sure to add joi and extension as keywords so that it's discoverable more easily.

Examples

const Joi = require('@hapi/joi');
const customJoi = Joi.extend((joi) => ({
    base: joi.number(),
    name: 'number',
    messages: {
        round: 'needs to be a rounded number', // Used below as 'number.round'
        dividable: 'needs to be dividable by {{q}}'
    },
    pre(value, state, prefs) {

        if (prefs.convert && this._flags.round) {
            return Math.round(value); // Change the value
        }

        return value; // Keep the value as it was
    },
    rules: [
        {
            name: 'round',
            setup(params) {

                this._flags.round = true;    // Set a flag for later use
            },
            validate(params, value, state, prefs) {

                if (value % 1 !== 0) {
                    // Generate an error, state and prefs need to be passed
                    return this.createError('number.round', value, {}, state, prefs);
                }

                return value; // Everything is OK
            }
        },
        {
            name: 'dividable',
            params: {
                q: joi.alternatives([joi.number().required(), joi.func().ref()])
            },
            validate(params, value, state, prefs) {

                if (value % params.q !== 0) {
                    // Generate an error, state and prefs need to be passed, q is used in the messages
                    return this.createError('number.dividable', value, { q: params.q }, state, prefs);
                }

                return value; // Everything is OK
            }
        }
    ]
}));

const schema = customJoi.number().round().dividable(3);

any

Generates a schema object that matches any data type.

const any = Joi.any();
any.validate('a', (err, value) => { });

schemaType

Gets the type of the schema.

const schema = Joi.string();

schema.schemaType === 'string';   // === true

any.allow(...values)

Allows values where:

  • values - one or more allowed values which can be of any type and will be matched against the validated value before applying any other rules. Supports references.

Note that this list of allowed values is in addition to any other permitted values. To create an exclusive list of values, see any.valid(value).

const schema = {
    a: Joi.any().allow('a'),
    b: Joi.any().allow('b', 'B')
};

any.concat(schema)

Returns a new type that is the result of adding the rules of one type to another where:

  • schema - a joi type to merge into the current schema. Can only be of the same type as the context type or any. If applied to an any type, the schema can be any other schema.
const a = Joi.string().valid('a');
const b = Joi.string().valid('b');
const ab = a.concat(b);

any.default([value, [description]])

Sets a default value if the original value is undefined where:

  • value - the value.
    • value supports references.
    • value may also be a function which returns the default value. If value is specified as a function that accepts a single parameter, that parameter will be a context object that can be used to derive the resulting value.
      • Use a function when setting a dynamic value, such as the current time. Ex: default(Date.now, 'time of creation')
      • Caution: this clones the object, which incurs some overhead so if you don't need access to the context define your method so that it does not accept any parameters.
    • without any value, default has no effect, except for object that will then create nested defaults (applying inner defaults of that object).

Note that if value is an object, any changes to the object after default() is called will change the reference and any future assignment.

Additionally, when specifying a method you must either have a description property on your method or the second parameter is required.

const generateUsername = (context) => {

  return context.firstname.toLowerCase() + '-' + context.lastname.toLowerCase();
};
generateUsername.description = 'generated username';

const schema = {
    username: Joi.string().default(generateUsername),
    firstname: Joi.string(),
    lastname: Joi.string(),
    created: Joi.date().default(Date.now, 'time of creation'),
    status: Joi.string().default('registered')
};

Joi.validate({
    firstname: 'Jane',
    lastname: 'Doe'
}, schema, (err, value) => {

    // value.status === 'registered'
    // value.username === 'jane-doe'
    // value.created will be the time of validation
});

Possible validation errors: any.default

any.describe()

Behaves the same as describe(schema) and returns an object that represents the internal configuration of the joi schema.

const schema = Joi.any().valid([ 'foo', 'bar' ]);

console.log(schema.describe());

Results in:

{ type: 'any',
  flags: { allowOnly: true },
  valids: [ 'foo', 'bar' ] }

any.description(desc)

Annotates the key where:

  • desc - the description string.
const schema = Joi.any().description('this key will match anything you give it');

any.empty(schema)

Considers anything that matches the schema to be empty (undefined).

  • schema - any object or joi schema to match. An undefined schema unsets that rule.
let schema = Joi.string().empty('');
schema.validate(''); // returns { error: null, value: undefined }
schema = schema.empty();
schema.validate(''); // returns { error: "value" is not allowed to be empty, value: '' }

any.error(err)

Overrides the default joi error with a custom error if the rule fails where:

  • err can be:
    • an instance of Error - the override error.
    • a function with the signature function(errors), where errors is an array of errors and it returns a single Error.

Note that if you provide an Error, it will be returned as-is, unmodified and undecorated with any of the normal error properties. If validation fails and another error is found before the error override, that error will be returned and the override will be ignored (unless the abortEarly option has been set to false).

const schema = Joi.string().error(new Error('Was REALLY expecting a string'));
schema.validate(3);     // returns error.message === 'Was REALLY expecting a string'
const schema = Joi.object({
    foo: Joi.number().min(0).error((errors) => new Error('"foo" requires a positive number'))
});
schema.validate({ foo: -2 });    // returns error.message === '"foo" requires a positive number'
const schema = Joi.object({
    foo: Joi.number().min(0).error((errors) => {

        return new Error('found errors with ' + errors.map((err) => `${err.type}(${err.local.limit}) with value ${err.local.value}`).join(' and '));
    })
});
schema.validate({ foo: -2 });    // returns error.message === 'child "foo" fails because [found errors with number.min(0) with value -2]'

any.example(...values)

Adds examples to the schema where:

  • values - each argument is an example value.

Note that no validation is performed on the provided examples. Calling this function again will override the previous examples.

const schema = Joi.string().min(4).example('abcd');

any.failover([value, [description]])

Sets a failover value if the original value failes passing validation where:

  • value - the failover value.
    • value supports references.
    • value may also be a function which returns the default value. If value is specified as a function that accepts a single parameter, that parameter will be a context object that can be used to derive the resulting value.
      • Use a function when setting a dynamic value, such as the current time. Ex: default(Date.now, 'time of creation')
      • Caution: this clones the object, which incurs some overhead so if you don't need access to the context define your method so that it does not accept any parameters.
    • without any value, default has no effect, except for object that will then create nested defaults (applying inner defaults of that object).

Note that if value is an object, any changes to the object after failover() is called will change the reference and any future assignment.

Additionally, when specifying a method you must either have a description property on your method or the second parameter is required.

Possible validation errors: any.failover

any.forbidden()

Marks a key as forbidden which will not allow any value except undefined. Used to explicitly forbid keys.

const schema = {
    a: Joi.any().forbidden()
};

Possible validation errors: any.unknown

any.invalid(...values) - aliases: disallow, not

Disallows values where:

  • values - the forbidden values which can be of any type and will be matched against the validated value before applying any other rules. Supports references.
const schema = {
    a: Joi.any().invalid('a'),
    b: Joi.any().invalid('b', 'B')
};

Possible validation errors: any.invalid

any.keep()

Same as rule({ keep: true }).

Note that keep() will terminate the current ruleset and cannot be followed by another rule option. Use rule() to apply multiple rule options.

any.label(name)

Overrides the key name in error messages.

  • name - the name of the key.
const schema = {
    first_name: Joi.string().label('First Name')
};

any.message(message)

Same as rule({ message }).

Note that message() will terminate the current ruleset and cannot be followed by another rule option. Use rule() to apply multiple rule options.

any.meta(meta)

Attaches metadata to the key where:

  • meta - the meta object to attach.
const schema = Joi.any().meta({ index: true });

any.notes(notes)

Annotates the key where:

  • notes - the notes string or array of strings.
const schema = Joi.any().notes(['this is special', 'this is important']);

any.optional()

Marks a key as optional which will allow undefined as values. Used to annotate the schema for readability as all keys are optional by default.

Note: this does not allow a null value. To do that, use any.allow(value). Or both!

const schema = Joi.any().optional();

any.prefs(options) = aliases: preferences, options

Overrides the global validate() options for the current key and any sub-key where:

const schema = Joi.any().prefs({ convert: false });

any.raw(isRaw)

Outputs the original untouched value instead of the casted value.

  • isRaw - whether to enable raw mode or not. Defaults to true.
const timestampSchema = Joi.date().timestamp();
timestampSchema.validate('12376834097810'); // { error: null, value: Sat Mar 17 2362 04:28:17 GMT-0500 (CDT) }

const rawTimestampSchema = Joi.date().timestamp().raw();
rawTimestampSchema.validate('12376834097810'); // { error: null, value: '12376834097810' }

any.required() - aliases: exist

Marks a key as required which will not allow undefined as value. All keys are optional by default.

const schema = Joi.any().required();

Possible validation errors: any.required

any.rule(options)

Applies a set of rule options to the current ruleset or last rule added where:

  • options - the rules to apply where:
    • keep - if true, the rules will not be replaced by the same unqiue rule later. For example, Joi.number().min(1).rule({ keep: true }).min(2) will keep both min() rules instead of the later rule overriding the first. Defaults to false.
    • message - a single message string or a messages object where each key is an error code and corresponding message string as value. The object is the same as the messages used as an option in Joi.validate(value, schema, options, callback). The strings can be plain messages or a message template.

When applying rule options, the last rule (e.g. min()) is used unless there is an active ruleset defined (e.g. $.min().max()) in which case the options are applied to all the provided rules. Once rules() is called, the previous rules can no longer be modified and any active ruleset is terminated.

any.ruleset - aliases: $

Starts a ruleset in order to apply multiple rule options. The set ends when rule() is called.

const schema = Joi.number().ruleset.min(1).max(10).rule({ message: 'Number must be between 1 and 10' });
const schema = Joi.number().$.min(1).max(10).rule({ message: 'Number must be between 1 and 10' });

any.strict(isStrict)

Strict mode sets the options.convert options to false which prevent type casting for the current key and any child keys.

  • isStrict - whether strict mode is enabled or not. Defaults to true.
const schema = Joi.any().strict();

any.strip()

Marks a key to be removed from a resulting object or array after validation. Used to sanitize output.

const schema = Joi.object({
    username: Joi.string(),
    password: Joi.string().strip()
});

schema.validate({ username: 'test', password: 'hunter2' }, (err, value) => {
    // value = { username: 'test' }
});

const schema = Joi.array().items(Joi.string(), Joi.any().strip());

schema.validate(['one', 'two', true, false, 1, 2], (err, value) => {
    // value = ['one', 'two']
});

any.tags(tags)

Annotates the key where:

  • tags - the tag string or array of strings.
const schema = Joi.any().tags(['api', 'user']);

any.unit(name)

Annotates the key where:

  • name - the unit name of the value.
const schema = Joi.number().unit('milliseconds');

any.valid(...values) - aliases: only, equal

Adds the provided values into the allowed whitelist and marks them as the only valid values allowed where:

  • values - one or more allowed values which can be of any type and will be matched against the validated value before applying any other rules. Supports references.
const schema = {
    a: Joi.any().valid('a'),
    b: Joi.any().valid('b', 'B')
};

Possible validation errors: any.allowOnly

any.validate(value, [options], [callback])

Validates a value using the schema and options where:

const schema = Joi.object({
    a: Joi.number()
});

const value = {
    a: '123'
};

schema.validate(value, (err, value) => { });
// err -> null
// value.a -> 123 (number, not string)

// or
const result = schema.validate(value);
// result.error -> null
// result.value -> { "a" : 123 }

// or
const promise = schema.validate(value);

any.when(condition, options)

Converts the type into an alternatives type with the conditions merged into the type definition where:

  • condition - the key name or reference, or a schema.
  • options - an object with:
    • is - the condition expressed as a joi schema. Anything that is not a joi schema will be converted using Joi.compile. By default, the is condition schema allows for undefined values. Use .required() to override. For example, use is: Joi.number().required() to guarantee that a joi reference exists and is a number.
    • then - if the condition is true, the joi schema to use.
    • otherwise - if the condition is false, the joi schema to use.
    • switch - an array of { is, then } conditions that are evaluated against the condition. The last item in the array may also contain otherwise.

If condition is a reference:

  • one of is or switch is required.
  • one of then, otherwise, or switch is required.
  • cannot use is or then with switch.
  • cannot specify otherwise both inside the last switch statement and outside.

If condition is a schema:

  • cannot specify is or switch.
  • one of then or otherwise is required.
const schema = {
    a: Joi.any().valid('x').when('b', { is: Joi.exist(), then: Joi.valid('y'), otherwise: Joi.valid('z') }),
    b: Joi.any()
};

Or with a schema:

const schema = Joi.object({
    a: Joi.any().valid('x'),
    b: Joi.any()
}).when(Joi.object({ b: Joi.exist() }).unknown(), {
    then: Joi.object({
        a: Joi.valid('y')
    }),
    otherwise: Joi.object({
        a: Joi.valid('z')
    })
});

Note that this style is much more useful when your whole schema depends on the value of one of its property, or if you find yourself repeating the check for many keys of an object. For example to validate this logic:

const schema = Joi.object({
    capacity: Joi.string()
        .valid(["A", "B", "C"])
        .required(),
    // required if capacity == "A"
    foo: Joi.when("capacity", {
        is: "A",
        then: Joi.string()
        .valid(["X", "Y", "Z"])
        .required()
    }),
    // required if capacity === "A" and foo !== "Z"
    bar: Joi.string()
}).when(
    Joi.object({
        capacity: Joi.only("A").required(),
        foo: Joi.not("Z")
    }).unknown(),
    {
        then: Joi.object({
            bar: Joi.required()
        })
    }
);

Alternatively, if you want to specify a specific type such as string, array, etc, you can do so like this:

const schema = {
    a: Joi.valid('a', 'b', 'other'),
    other: Joi.string()
        .when('a', { is: 'other', then: Joi.required() }),
};

If you need to validate a child key inside a nested object based on a sibling's value, you can do so like this:

const schema = Joi.object({
    a: Joi.boolean().required(),
    b: Joi.object()
        .keys({
            c: Joi.string(),
            d: Joi.number().required()
        })
        .required()
        .when('a', {
            is: true,
            then: Joi.object({ c: Joi.required() })		// b.c is required only when a is true
        })
});

If you want to validate one key based on the existence of another key, you can do so like the following (notice the use of required()):

const schema = Joi.object({
    min: Joi.number(),
    max: Joi.number().when('min', {
        is: Joi.number().required(),
        then: Joi.number().greater(Joi.ref('min')),
    }),
});

To evaluate multiple values on a single reference:

const schema = Joi.object({
    a: Joi.number().required(),
    b: Joi.number()
        .when('a', {
            switch: [
                { is: 0, then: Joi.valid(1) },
                { is: 1, then: Joi.valid(2) },
                { is: 2, then: Joi.valid(3) }
            ],
            otherwise: Joi.valid(4)
        })
});

Or shorter:

const schema = Joi.object({
    a: Joi.number().required(),
    b: Joi.number()
        .when('a', [
            { is: 0, then: 1 },
            { is: 1, then: 2 },
            { is: 2, then: 3, otherwise: 4 }
        ])
});

array - inherits from Any

Generates a schema object that matches an array data type. Note that undefined values inside arrays are not allowed by default but can be by using sparse(). If the validation convert option is on (enabled by default), a string will be converted to an array if specified via JSON.parse().

Supports the same methods of the any() type.

const array = Joi.array().items(Joi.string().valid('a', 'b'));
array.validate(['a', 'b', 'a'], (err, value) => { });

Possible validation errors: array.base

array.has(schema)

Verifies that a schema validates at least one of the values in the array, where:

  • schema - the validation rules required to satisfy the check. If the schema includes references, they are resolved against the array item being tested, not the value of the ref target.
const schema = Joi.array().items(
  Joi.object({
    a: Joi.string(),
    b: Joi.number()
  })
).has(Joi.object({ a: Joi.string().valid('a'), b: Joi.number() }))

Possible validation errors: array.hasKnown, array.hasUnknown

array.items(...types)

Lists the types allowed for the array values where:

  • types - one or more joi schema objects to validate each array item against.

If a given type is .required() then there must be a matching item in the array. If a type is .forbidden() then it cannot appear in the array. Required items can be added multiple times to signify that multiple items must be found. Errors will contain the number of items that didn't match. Any unmatched item having a label will be mentioned explicitly.

const schema = Joi.array().items(Joi.string(), Joi.number()); // array may contain strings and numbers
const schema = Joi.array().items(Joi.string().required(), Joi.string().required()); // array must contain at least two strings
const schema = Joi.array().items(Joi.string().valid('not allowed').forbidden(), Joi.string()); // array may contain strings, but none of those strings can match 'not allowed'
const schema = Joi.array().items(Joi.string().label('My string').required(), Joi.number().required()); // If this fails it can result in `[ValidationError: "value" does not contain [My string] and 1 other required value(s)]`

Possible validation errors: array.excludes, [array.includesRequiredBoth], [array.includesRequiredKnowns], [array.includesRequiredUnknowns], array.includes

array.length(limit)

Specifies the exact number of items in the array where:

  • limit - the number of array items allowed or a reference.
const schema = Joi.array().length(5);
const schema = Joi.object({
  limit: Joi.number().integer().required(),
  numbers: Joi.array().length(Joi.ref('limit')).required()
});

Possible validation errors: array.length, array.ref

array.max(limit)

Specifies the maximum number of items in the array where:

  • limit - the highest number of array items allowed or a reference.
const schema = Joi.array().max(10);
const schema = Joi.object({
  limit: Joi.number().integer().required(),
  numbers: Joi.array().max(Joi.ref('limit')).required()
});

Possible validation errors: array.max, array.ref

array.min(limit)

Specifies the minimum number of items in the array where:

  • limit - the lowest number of array items allowed or a reference.
const schema = Joi.array().min(2);
const schema = Joi.object({
  limit: Joi.number().integer().required(),
  numbers: Joi.array().min(Joi.ref('limit')).required()
});

Possible validation errors: array.min, array.ref

array.ordered(...type)

Lists the types in sequence order for the array values where:

  • types - one or more joi schema objects to validate against each array item in sequence order.

If a given type is .required() then there must be a matching item with the same index position in the array. Errors will contain the number of items that didn't match. Any unmatched item having a label will be mentioned explicitly.

const schema = Joi.array().ordered(Joi.string().required(), Joi.number().required()); // array must have first item as string and second item as number
const schema = Joi.array().ordered(Joi.string().required()).items(Joi.number().required()); // array must have first item as string and 1 or more subsequent items as number
const schema = Joi.array().ordered(Joi.string().required(), Joi.number()); // array must have first item as string and optionally second item as number

Possible validation errors: array.excludes, array.includes, array.orderedLength

array.single([enabled])

Allows single values to be checked against rules as if it were provided as an array.

enabled can be used with a falsy value to go back to the default behavior.

const schema = Joi.array().items(Joi.number()).single();
schema.validate([4]); // returns `{ error: null, value: [ 4 ] }`
schema.validate(4); // returns `{ error: null, value: [ 4 ] }`

Possible validation errors: array.excludes, array.includes

array.sort([options])

Requires the array to comply with the specified sort order where:

  • options - optional settings:
    • order - the sort order. Allowed values:
      • 'ascending' - sort the array in ascending order. This is the default.
      • 'descending' - sort the array in descending order.
    • by - a key name or reference to sort array objects by. Defautls to the entire value.

Notes:

  • if the convert preference is true, the array is modified to match the required sort order.
  • undefined values are always placed at the end of the array regardless of the sort order.
  • can only sort string and number items or item key values.

Possible validation errors: array.sort, array.sort.unsupported, array.sort.mismatching

array.sparse([enabled])

Allows this array to be sparse. enabled can be used with a falsy value to go back to the default behavior.

let schema = Joi.array().sparse(); // undefined values are now allowed
schema = schema.sparse(false); // undefined values are now denied

Possible validation errors: array.sparse

array.unique([comparator, [options]])

Requires the array values to be unique where:

  • comparator - an optional custom comparator that is either:
    • a function that takes 2 parameters to compare. This function should return whether the 2 parameters are equal or not, you are also responsible for this function not to fail, any Error would bubble out of Joi.
    • a string in dot notation representing the path of the element to do uniqueness check on. Any missing path will be considered undefined, and can as well only exist once.
  • options - optional settings:
    • ignoreUndefined - if true, undefined values for the dot notation string comparator will not cause the array to fail on uniqueness. Defaults to false.
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.

Note: remember that if you provide a custom comparator function, different types can be passed as parameter depending on the rules you set on items.

Be aware that a deep equality is performed on elements of the array having a type of object, a performance penalty is to be expected for this kind of operation.

const schema = Joi.array().unique();
const schema = Joi.array().unique((a, b) => a.property === b.property);
const schema = Joi.array().unique('customer.id');
let schema = Joi.array().unique('identifier');

schema.validate([{}, {}]);
// ValidationError: "value" position 1 contains a duplicate value

schema = Joi.array().unique('identifier', { ignoreUndefined: true });

schema.validate([{}, {}]);
// error: null

Possible validation errors: array.unique

boolean - inherits from Any

Generates a schema object that matches a boolean data type. Can also be called via bool(). If the validation convert option is on (enabled by default), a string (either "true" or "false") will be converted to a boolean if specified.

Supports the same methods of the any() type.

const boolean = Joi.boolean();
boolean.validate(true, (err, value) => { }); // Valid

boolean.validate(1, (err, value) => { }); // Invalid

Possible validation errors: boolean.base

boolean.truthy(...values)

Allows for additional values to be considered valid booleans by converting them to true during validation. Requires the validation convert option to be true.

String comparisons are by default case insensitive, see boolean.insensitive() to change this behavior.

const boolean = Joi.boolean().truthy('Y');
boolean.validate('Y', (err, value) => { }); // Valid

boolean.falsy(...values)

Allows for additional values to be considered valid booleans by converting them to false during validation. Requires the validation convert option to be true.

String comparisons are by default case insensitive, see boolean.insensitive() to change this behavior.

const boolean = Joi.boolean().falsy('N');
boolean.validate('N', (err, value) => { }); // Valid

boolean.insensitive([enabled])

Allows the values provided to truthy and falsy as well as the "true" and "false" default conversion (when not in strict() mode) to be matched in a case insensitive manner.

Parameters are:

  • enabled - optional parameter defaulting to true which allows you to reset the behavior of insensitive by providing a falsy value.
const schema = Joi.boolean().truthy('yes').falsy('no').insensitive(false);

binary - inherits from Any

Generates a schema object that matches a Buffer data type. If the validation convert option is on (enabled by default), a string will be converted to a Buffer if specified.

Supports the same methods of the any() type.

const schema = Joi.binary();

Possible validation errors: binary.base

binary.encoding(encoding)

Sets the string encoding format if a string input is converted to a buffer where:

  • encoding - the encoding scheme.
const schema = Joi.binary().encoding('base64');

binary.min(limit)

Specifies the minimum length of the buffer where:

  • limit - the lowest size of the buffer or a reference.
const schema = Joi.binary().min(2);

Possible validation errors: binary.min, binary.ref

binary.max(limit)

Specifies the maximum length of the buffer where:

  • limit - the highest size of the buffer or a reference.
const schema = Joi.binary().max(10);

Possible validation errors: binary.max, binary.ref

binary.length(limit)

Specifies the exact length of the buffer:

  • limit - the size of buffer allowed or a reference.
const schema = Joi.binary().length(5);

Possible validation errors: binary.length, binary.ref

date - inherits from Any

Generates a schema object that matches a date type (as well as a JavaScript date string or number of milliseconds). If the validation convert option is on (enabled by default), a string or number will be converted to a Date if specified.

Supports the same methods of the any() type.

const date = Joi.date();
date.validate('12-21-2012', (err, value) => { });

Possible validation errors: date.base, date.strict

date.min(date)

Specifies the oldest date allowed where:

  • date - the oldest date allowed or a reference.
const schema = Joi.date().min('1-1-1974');

Notes: 'now' can be passed in lieu of date so as to always compare relatively to the current date, allowing to explicitly ensure a date is either in the past or in the future.

const schema = Joi.date().min('now');
const schema = Joi.object({
  from: Joi.date().required(),
  to: Joi.date().min(Joi.ref('from')).required()
});

Possible validation errors: date.min, date.ref

date.max(date)

Specifies the latest date allowed where:

  • date - the latest date allowed or a reference.
const schema = Joi.date().max('12-31-2020');

Notes: 'now' can be passed in lieu of date so as to always compare relatively to the current date, allowing to explicitly ensure a date is either in the past or in the future.

const schema = Joi.date().max('now');
const schema = Joi.object({
  from: Joi.date().max(Joi.ref('to')).required(),
  to: Joi.date().required()
});

Possible validation errors: date.max, date.ref

date.greater(date)

Specifies that the value must be greater than date (or a reference).

const schema = Joi.date().greater('1-1-1974');

Notes: 'now' can be passed in lieu of date so as to always compare relatively to the current date, allowing to explicitly ensure a date is either in the past or in the future.

const schema = Joi.date().greater('now');
const schema = Joi.object({
  from: Joi.date().required(),
  to: Joi.date().greater(Joi.ref('from')).required()
});

Possible validation errors: date.greater, date.ref

date.less(date)

Specifies that the value must be less than date (or a reference).

const schema = Joi.date().less('12-31-2020');

Notes: `'now'` can be passed in lieu of `date` so as to always compare relatively to the current date, allowing to explicitly ensure a date is either in the past or in the future.

```js
const schema = Joi.date().max('now');
const schema = Joi.object({
  from: Joi.date().less(Joi.ref('to')).required(),
  to: Joi.date().required()
});

Possible validation errors: date.less, date.ref

date.iso()

Requires the string value to be in valid ISO 8601 date format.

const schema = Joi.date().iso();

Possible validation errors: date.isoDate

date.timestamp([type])

Requires the value to be a timestamp interval from Unix Time.

  • type - the type of timestamp (allowed values are unix or javascript [default])
const schema = Joi.date().timestamp(); // defaults to javascript timestamp
const schema = Joi.date().timestamp('javascript'); // also, for javascript timestamp (milliseconds)
const schema = Joi.date().timestamp('unix'); // for unix timestamp (seconds)

Possible validation errors: date.timestamp.javascript, date.timestamp.unix

func - inherits from Any

Generates a schema object that matches a function type.

Supports the same methods of the object() type. Note that validating a function keys will cause the function to be cloned. While the function will retain its prototype and closure, it will lose its length property value (will be set to 0).

const func = Joi.func();
func.validate(function () {}, (err, value) => { });

Possible validation errors: function.base

func.arity(n)

Specifies the arity of the function where:

  • n - the arity expected.
const schema = Joi.func().arity(2);

Possible validation errors: function.arity

func.minArity(n)

Specifies the minimal arity of the function where:

  • n - the minimal arity expected.
const schema = Joi.func().minArity(1);

Possible validation errors: function.minArity

func.maxArity(n)

Specifies the maximal arity of the function where:

  • n - the maximum arity expected.
const schema = Joi.func().maxArity(3);

Possible validation errors: function.maxArity

func.class()

Requires the function to be a class.

const schema = Joi.func().class();

Possible validation errors: function.class

number - inherits from Any

Generates a schema object that matches a number data type (as well as strings that can be converted to numbers).

By default, it only allows safe numbers, see number.unsafe().

If the validation convert option is on (enabled by default), a string will be converted to a number if specified. Also, if convert is on and number.precision() is used, the value will be converted to the specified precision as well.

Infinity and -Infinity are invalid by default, you can change that behavior by calling allow(Infinity, -Infinity).

Supports the same methods of the any() type.

const number = Joi.number();
number.validate(5, (err, value) => { });

Possible validation errors: number.base

number.unsafe([enabled])

By default, numbers must be within JavaScript's safety range (Number.MIN_SAFE_INTEGER & Number.MAX_SAFE_INTEGER), and when given a string, should be converted without loss of information. You can allow unsafe numbers at your own risks by calling number.unsafe().

Parameters are:

  • enabled - optional parameter defaulting to true which allows you to reset the behavior of unsafe by providing a falsy value.
const safeNumber = Joi.number();
safeNumber.validate(90071992547409924);
// error -> "value" must be a safe number

const unsafeNumber = Joi.number().unsafe();
unsafeNumber.validate(90071992547409924);
// error -> null
// value -> 90071992547409920

Possible validation errors: number.unsafe

number.min(limit)

Specifies the minimum value where:

  • limit - the minimum value allowed or a reference.
const schema = Joi.number().min(2);
const schema = Joi.object({
  min: Joi.number().required(),
  max: Joi.number().min(Joi.ref('min')).required()
});

Possible validation errors: number.min, number.ref

number.max(limit)

Specifies the maximum value where:

  • limit - the maximum value allowed or a reference.
const schema = Joi.number().max(10);
const schema = Joi.object({
  min: Joi.number().max(Joi.ref('max')).required(),
  max: Joi.number().required()
});

Possible validation errors: number.max, number.ref

number.greater(limit)

Specifies that the value must be greater than limit or a reference.

const schema = Joi.number().greater(5);
const schema = Joi.object({
  min: Joi.number().required(),
  max: Joi.number().greater(Joi.ref('min')).required()
});

Possible validation errors: number.greater, number.ref

number.less(limit)

Specifies that the value must be less than limit or a reference.

const schema = Joi.number().less(10);
const schema = Joi.object({
  min: Joi.number().less(Joi.ref('max')).required(),
  max: Joi.number().required()
});

Possible validation errors: number.less, number.ref

number.integer()

Requires the number to be an integer (no floating point).

const schema = Joi.number().integer();

Possible validation errors: number.base

number.precision(limit)

Specifies the maximum number of decimal places where:

  • limit - the maximum number of decimal places allowed.
const schema = Joi.number().precision(2);

Possible validation errors: number.integer

number.multiple(base)

Specifies that the value must be a multiple of base (or a reference):

const schema = Joi.number().multiple(3);

Notes: Joi.number.multiple(base) uses the modulo operator (%) to determine if a number is multiple of another number. Therefore, it has the normal limitations of Javascript modulo operator. The results with decimal/floats may be incorrect.

Possible validation errors: number.multiple, number.ref

number.positive()

Requires the number to be positive.

const schema = Joi.number().positive();

Possible validation errors: number.positive

number.negative()

Requires the number to be negative.

const schema = Joi.number().negative();

Possible validation errors: number.negative

number.port()

Requires the number to be a TCP port, so between 0 and 65535.

const schema = Joi.number().port();

Possible validation errors: number.port

object - inherits from Any

Generates a schema object that matches an object data type (as well as JSON strings that parsed into objects). Defaults to allowing any child key. If the validation convert option is on (enabled by default), a string will be converted to an object if specified via JSON.parse().

Supports the same methods of the any() type.

const object = Joi.object({
    a: Joi.number().min(1).max(10).integer(),
    b: 'some string'
});

object.validate({ a: 5 }, (err, value) => { });

Possible validation errors: object.base

object.keys([schema])

Sets or extends the allowed object keys where:

  • schema - optional object where each key is assigned a joi type object. If schema is {} no keys allowed. If schema is null or undefined, any key allowed. If schema is an object with keys, the keys are added to any previously defined keys (but narrows the selection if all keys previously allowed). Defaults to 'undefined' which allows any child key.
const base = Joi.object().keys({
    a: Joi.number(),
    b: Joi.string()
});
// Validate keys a, b and c.
const extended = base.keys({
    c: Joi.boolean()
});

Notes: We have three different ways to define a schema for performing a validation

  • Using the plain JS object notation:
const schema = {
    a: Joi.string(),
    b: Joi.number()
};
  • Using the Joi.object([schema]) notation
const schema = Joi.object({
    a: Joi.string(),
    b: Joi.number()
});
  • Using the Joi.object().keys([schema]) notation
const schema = Joi.object().keys({
    a: Joi.string(),
    b: Joi.number()
});

Possible validation errors: object.allowUnknown

While all these three objects defined above will result in the same validation object, there are some differences in using one or another:

{} notation

When using the {} notation, you are just defining a plain JS object, which isn't a schema object. You can pass it to the validation method but you can't call validate() method of the object because it's just a plain JS object.

Besides, passing the {} object to the validate() method each time, will perform an expensive schema compilation operation on every validation.

Joi.object([schema]) notation

Using Joi.object([schema]) will return a schema object, so you can call the validate() method directly, e.g:

const schema = Joi.object({
    a: Joi.boolean()
});

schema.validate(true, (err, value) => {
    console.log('err: ', err);
});

When you use Joi.object([schema]), it gets compiled the first time, so you can pass it to the validate() method multiple times and no overhead is added.

Another benefits of using Joi.object([schema]) instead of a plain JS object is that you can set any options on the object like allowing unknown keys, e.g:

const schema = Joi.object({
    arg: Joi.string().valid('firstname', 'lastname', 'title', 'company', 'jobtitle'),
    value: Joi.string(),
})
    .pattern(/firstname|lastname/, Joi.string().min(2));
Joi.object().keys([schema]) notation

This is basically the same as Joi.object([schema]), but using Joi.object().keys([schema]) is more useful when you want to add more keys (e.g. call keys() multiple times). If you are only adding one set of keys, you can skip the keys() method and just use object() directly.

Some people like to use keys() to make the code more explicit (this is style only).

object.append([schema])

Appends the allowed object keys where:

  • schema - optional object where each key is assigned a joi type object. If schema is null,undefined or {} no changes will be applied. Uses object.keys([schema]) to append keys.
// Validate key a
const base = Joi.object({
    a: Joi.number()
});
// Validate keys a, b.
const extended = base.append({
    b: Joi.string()
});

object.min(limit)

Specifies the minimum number of keys in the object where:

  • limit - the lowest number of keys allowed or a reference.
const schema = Joi.object().min(2);

Possible validation errors: object.min, object.ref

object.max(limit)

Specifies the maximum number of keys in the object where:

  • limit - the highest number of object keys allowed or a reference.
const schema = Joi.object().max(10);

Possible validation errors: object.max, object.ref

object.length(limit)

Specifies the exact number of keys in the object where or a reference:

  • limit - the number of object keys allowed.
const schema = Joi.object().length(5);

Possible validation errors: object.length, object.ref

object.pattern(pattern, schema)

Specify validation rules for unknown keys matching a pattern where:

  • pattern - a pattern that can be either a regular expression or a joi schema that will be tested against the unknown key names.
  • schema - the schema object matching keys must validate against.
const schema = Joi.object({
    a: Joi.string()
}).pattern(/\w\d/, Joi.boolean());

// OR

const schema = Joi.object({
    a: Joi.string()
}).pattern(Joi.string().min(2).max(5), Joi.boolean());

object.and(...peers, [options])

Defines an all-or-nothing relationship between keys where if one of the peers is present, all of them are required as well where:

  • peers - the string key names of which if one present, all are required.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).and('a', 'b');

Possible validation errors: object.and

object.nand(...peers, [options])

Defines a relationship between keys where not all peers can be present at the same time where:

  • peers - the key names of which if one present, the others may not all be present.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).nand('a', 'b');

Possible validation errors: object.nand

object.or(...peers, [options])

Defines a relationship between keys where one of the peers is required (and more than one is allowed) where:

  • peers - the key names of which at least one must appear.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).or('a', 'b');

Possible validation errors: object.missing

object.xor(...peers, [options])

Defines an exclusive relationship between a set of keys where one of them is required but not at the same time where:

  • peers - the exclusive key names that must not appear together but where one of them is required.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).xor('a', 'b');

Possible validation errors: object.xor, object.missing

object.oxor(...peers, [options])

Defines an exclusive relationship between a set of keys where only one is allowed but none are required where:

  • peers - the exclusive key names that must not appear together but where none are required.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).oxor('a', 'b');

Possible validation errors: object.oxor

object.with(key, peers, [options])

Requires the presence of other keys whenever the specified key is present where:

  • key - the reference key.
  • peers - the required peer key names that must appear together with key. peers can be a single string value or an array of string values.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.

Note that unlike object.and(), with() creates a dependency only between the key and each of the peers, not between the peers themselves.

const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).with('a', 'b');

Possible validation errors: object.with

object.without(key, peers, [options])

Forbids the presence of other keys whenever the specified is present where:

  • key - the reference key.
  • peers - the forbidden peer key names that must not appear together with key. peers can be a single string value or an array of string values.
  • options - optional settings:
    • separator - overrides the default . hierarchy separator. Set to false to treat the key as a literal value.
const schema = Joi.object({
    a: Joi.any(),
    b: Joi.any()
}).without('a', ['b']);

Possible validation errors: object.without

object.ref()

Requires the object to be a joi reference.

const schema = Joi.object().ref();

Possible validation errors: object.refType

object.rename(from, to, [options])

Renames a key to another name (deletes the renamed key) where:

  • from - the original key name or a regular expression matching keys.
  • to - the new key name. to can be set to a template which is rendered at runtime using the current value, global context, and local context if from is a regular expression (e.g. the expression /^(\d+)$/ will match any all-digits keys with a capture group that is accessible in the template via {#1}).
  • options - an optional object with the following optional keys:
    • alias - if true, does not delete the old key name, keeping both the new and old keys in place. Defaults to false.
    • multiple - if true, allows renaming multiple keys to the same destination where the last rename wins. Defaults to false.
    • override - if true, allows renaming a key over an existing key. Defaults to false.
    • ignoreUndefined - if true, skip renaming of a key if it's undefined. Defaults to false.

Keys are renamed before any other validation rules are applied. If to is a template that references the object own keys (e.g. '{.prefix}-{#1}'), the value of these keys is the raw input value, not the value generated after validation.

const object = Joi.object({
    a: Joi.number()
}).rename('b', 'a');

object.validate({ b: 5 }, (err, value) => { });

Using a regular expression:

const regex = /^foobar$/i;

const schema = Joi.object({
  fooBar: Joi.string()
}).rename(regex, 'fooBar');

schema.validate({ FooBar: 'a'}, (err, value) => {});

Using a regular expression with template:

const schema = Joi.object()
    .rename(/^(\d+)$/, Joi.template('x{#1}x'))
    .pattern(/^x\d+x$/, Joi.any());

const input = {
    123: 'x',
    1: 'y',
    0: 'z',
    x4x: 'test'
};

const value = await Joi.compile(schema).validate(input);
// value === { x123x: 'x', x1x: 'y', x0x: 'z', x4x: 'test' }

Possible validation errors: object.rename.multiple, object.rename.override

object.assert(ref, schema, [message])

Verifies an assertion where:

  • ref - the key name or reference.
  • schema - the validation rules required to satisfy the assertion. If the schema includes references, they are resolved against the object value, not the value of the ref target.
  • message - optional human-readable message used when the assertion fails. Defaults to 'failed to pass the assertion test'.
const schema = Joi.object({
    a: {
        b: Joi.string(),
        c: Joi.number()
    },
    d: {
        e: Joi.any()
    }
}).assert('d.e', Joi.ref('a.c'), 'equal to a.c');

Possible validation errors: object.assert

object.unknown([allow])

Overrides the handling of unknown keys for the scope of the current object only (does not apply to children) where:

  • allow - if false, unknown keys are not allowed, otherwise unknown keys are ignored.
const schema = Joi.object({ a: Joi.any() }).unknown();

Possible validation errors: object.allowUnknown

object.type(constructor, [name])

Requires the object to be an instance of a given constructor where:

  • constructor - the constructor function that the object must be an instance of.
  • name - an alternate name to use in validation errors. This is useful when the constructor function does not have a name.
const schema = Joi.object().type(RegExp);

Possible validation errors: object.type

object.schema([type])

Requires the object to be a joi schema instance where:

  • type - optional joi schema to require.
const schema = Joi.object().schema();

Possible validation errors: object.schema

object.requiredKeys(...children)

Sets the specified children to required.

  • children - the keys to specified as required.
const schema = Joi.object({ a: { b: Joi.number() }, c: { d: Joi.string() } });
const requiredSchema = schema.requiredKeys('', 'a.b', 'c', 'c.d');

Note that in this example '' means the current object, a is not required but b is, as well as c and d.

object.optionalKeys(...children)

Sets the specified children to optional.

  • children - the keys to specified as optional.
const schema = Joi.object({ a: { b: Joi.number().required() }, c: { d: Joi.string().required() } });
const optionalSchema = schema.optionalKeys('a.b', 'c.d');

The behavior is exactly the same as requiredKeys.

object.forbiddenKeys(...children)

Sets the specified children to forbidden.

  • children - the keys specified as forbidden.
const schema = Joi.object({ a: { b: Joi.number().required() }, c: { d: Joi.string().required() } });
const optionalSchema = schema.forbiddenKeys('a.b', 'c.d');

The behavior is exactly the same as requiredKeys.

string - inherits from Any

Generates a schema object that matches a string data type. Note that empty strings are not allowed by default and must be enabled with allow(''). However, if you want to specify a default value in case of empty string you have to use a different pattern: Joi.string().empty('').default('default value'). This tells joi that the empty string should be considered as an empty value (instead of invalid) and which value to use as default.

If the validation convert option is on (enabled by default), a string will be converted using the specified modifiers for string.lowercase(), string.uppercase(), string.trim(), and each replacement specified with string.replace().

Supports the same methods of the any() type.

const schema = Joi.string().min(1).max(10);
schema.validate('12345', (err, value) => { });

Possible validation errors: string.base, any.empty

string.insensitive()

Allows the value to match any whitelist or blacklist item in a case insensitive comparison.

const schema = Joi.string().valid('a').insensitive();

string.min(limit, [encoding])

Specifies the minimum number string characters where:

  • limit - the minimum number of string characters required or a reference.
  • encoding - if specified, the string length is calculated in bytes using the provided encoding.
const schema = Joi.string().min(2);
const schema = Joi.object({
  min: Joi.string().required(),
  value: Joi.string().min(Joi.ref('min'), 'utf8').required()
});

Possible validation errors: string.min, string.ref

string.max(limit, [encoding])

Specifies the maximum number of string characters where:

  • limit - the maximum number of string characters allowed or a reference.
  • encoding - if specified, the string length is calculated in bytes using the provided encoding.
const schema = Joi.string().max(10);
const schema = Joi.object({
  max: Joi.string().required(),
  value: Joi.string().max(Joi.ref('max'), 'utf8').required()
});

Possible validation errors: string.max, string.ref

string.truncate([enabled])

Specifies whether the string.max() limit should be used as a truncation.

Parameters are:

  • enabled - optional parameter defaulting to true which allows you to reset the behavior of truncate by providing a falsy value.
const schema = Joi.string().max(5).truncate();

string.creditCard()

Requires the number to be a credit card number (Using Luhn Algorithm).

const schema = Joi.string().creditCard();

Possible validation errors: string.creditCard

string.length(limit, [encoding])

Specifies the exact string length required where:

  • limit - the required string length or a reference.
  • encoding - if specified, the string length is calculated in bytes using the provided encoding.
const schema = Joi.string().length(5);
const schema = Joi.object({
  length: Joi.string().required(),
  value: Joi.string().length(Joi.ref('length'), 'utf8').required()
});

Possible validation errors: string.length, string.ref

string.regex(pattern, [name | options])

Defines a regular expression rule where:

  • pattern - a regular expression object the string value must match against.
  • name - optional name for patterns (useful with multiple patterns).
  • options - an optional configuration object with the following supported properties:
    • name - optional pattern name.
    • invert - optional boolean flag. Defaults to false behavior. If specified as true, the provided pattern will be disallowed instead of required.
const schema = Joi.string().regex(/^[abc]+$/);

const inlineNamedSchema = Joi.string().regex(/^[0-9]+$/, 'numbers');
inlineNamedSchema.validate('alpha'); // ValidationError: "value" with value "alpha" fails to match the numbers pattern

const namedSchema = Joi.string().regex(/^[0-9]+$/, { name: 'numbers'});
namedSchema.validate('alpha'); // ValidationError: "value" with value "alpha" fails to match the numbers pattern

const invertedSchema = Joi.string().regex(/^[a-z]+$/, { invert: true });
invertedSchema.validate('lowercase'); // ValidationError: "value" with value "lowercase" matches the inverted pattern: [a-z]

const invertedNamedSchema = Joi.string().regex(/^[a-z]+$/, { name: 'alpha', invert: true });
invertedNamedSchema.validate('lowercase'); // ValidationError: "value" with value "lowercase" matches the inverted alpha pattern

Possible validation errors: string.regex.base, string.regex.invert.base, string.regex.invert.name, string.regex.name

string.replace(pattern, replacement)

Replace characters matching the given pattern with the specified replacement string where:

  • pattern - a regular expression object to match against, or a string of which all occurrences will be replaced.
  • replacement - the string that will replace the pattern.
const schema = Joi.string().replace(/b/gi, 'x');
schema.validate('abBc', (err, value) => {
  // here value will be 'axxc'
});

When pattern is a string all its occurrences will be replaced.

string.alphanum()

Requires the string value to only contain a-z, A-Z, and 0-9.

const schema = Joi.string().alphanum();

Possible validation errors: string.alphanum

string.token()

Requires the string value to only contain a-z, A-Z, 0-9, and underscore _.

const schema = Joi.string().token();

Possible validation errors: string.token

string.domain([options])

Requires the string value to be a valid domain name.

  • options - optional settings:
    • allowUnicode - if true, Unicode characters are permitted. Defaults to true.
    • minDomainSegments - Number of segments required for the domain. Defaults to 2.
    • tlds - options for TLD (top level domain) validation. By default, the TLD must be a valid name listed on the IANA registry. To disable validation, set tlds to false. To customize how TLDs are validated, set one of these:
      • allow - one of:
        • true to use the IANA list of registered TLDs. This is the default value.
        • false to allow any TLD not listed in the deny list, if present.
        • a Set or array of the allowed TLDs. Cannot be used together with deny.
      • deny - one of:
        • a Set or array of the forbidden TLDs. Cannot be used together with a custom allow list.
const schema = Joi.string().domain();

Possible validation errors: string.domain

string.email([options])

Requires the string value to be a valid email address.

  • options - optional settings:
    • allowUnicode - if true, Unicode characters are permitted. Defaults to true.
    • minDomainSegments - Number of segments required for the domain. The default setting excludes single segment domains such as example@io which is a valid email but very uncommon. Defaults to 2.
    • multiple - if true, allows multiple email addresses in a single string, separated by , or the separator characters. Defaults to false.
    • separator - when multiple is true, overrides the default , separator. String can be a single character or multiple separator characters. Defaults to ','.
    • tlds - options for TLD (top level domain) validation. By default, the TLD must be a valid name listed on the IANA registry. To disable validation, set tlds to false. To customize how TLDs are validated, set one of these:
      • allow - one of:
        • true to use the IANA list of registered TLDs. This is the default value.
        • false to allow any TLD not listed in the deny list, if present.
        • a Set or array of the allowed TLDs. Cannot be used together with deny.
      • deny - one of:
        • a Set or array of the forbidden TLDs. Cannot be used together with a custom allow list.
const schema = Joi.string().email();

Possible validation errors: string.email

string.ip([options])

Requires the string value to be a valid ip address.

  • options - optional settings:
    • version - One or more IP address versions to validate against. Valid values: ipv4, ipv6, ipvfuture
    • cidr - Used to determine if a CIDR is allowed or not. Valid values: optional, required, forbidden
// Accept only ipv4 and ipv6 addresses with a CIDR
const schema = Joi.string().ip({
  version: [
    'ipv4',
    'ipv6'
  ],
  cidr: 'required'
});

Possible validation errors: string.ip, string.ipVersion

string.uri([options])

Requires the string value to be a valid RFC 3986 URI.

  • options - optional settings:
    • scheme - Specifies one or more acceptable Schemes, should only include the scheme name. Can be an Array or String (strings are automatically escaped for use in a Regular Expression).
    • allowRelative - Allow relative URIs. Defaults to false.
    • relativeOnly - Restrict only relative URIs. Defaults to false.
    • allowQuerySquareBrackets - Allows unencoded square brackets inside the query string. This is NOT RFC 3986 compliant but query strings like abc[]=123&abc[]=456 are very common these days. Defaults to false.
    • domain - Validate the domain component using the options specified in string.domain().
// Accept git or git http/https
const schema = Joi.string().uri({
  scheme: [
    'git',
    /git\+https?/
  ]
});

Possible validation errors: string.uri, string.uriCustomScheme, string.uriRelativeOnly, string.domain

string.guid() - aliases: uuid

Requires the string value to be a valid GUID.

  • options - optional settings:
    • version - Specifies one or more acceptable versions. Can be an Array or String with the following values: uuidv1, uuidv2, uuidv3, uuidv4, or uuidv5. If no version is specified then it is assumed to be a generic guid which will not validate the version or variant of the guid and just check for general structure format.
const schema = Joi.string().guid({
    version: [
        'uuidv4',
        'uuidv5'
    ]
});

Possible validation errors: string.guid

string.hex([options])

Requires the string value to be a valid hexadecimal string.

  • options - optional settings:
    • byteAligned - Boolean specifying whether you want to check that the hexadecimal string is byte aligned. If convert is true, a 0 will be added in front of the string in case it needs to be aligned. Defaults to false.
const schema = Joi.string().hex();

Possible validation errors: string.hex, string.hexAlign

string.base64([options])

Requires the string value to be a valid base64 string; does not check the decoded value.

  • options - optional settings:
    • paddingRequired - if true, the string must be properly padded with the = characters. Defaults to true.
    • urlSafe - if true, uses the URI-safe base64 format which replaces + with - and \ with _. Defaults to false.

Padding characters are not required for decoding, as the number of missing bytes can be inferred from the number of digits. With that said, try to use padding if at all possible.

const schema = Joi.string().base64();
schema.validate('VE9PTUFOWVNFQ1JFVFM'); // ValidationError: "value" must be a valid base64 string
schema.validate('VE9PTUFOWVNFQ1JFVFM='); // No Error

const paddingRequiredSchema = Joi.string().base64({ paddingRequired: true });
paddingRequiredSchema.validate('VE9PTUFOWVNFQ1JFVFM'); // ValidationError: "value" must be a valid base64 string
paddingRequiredSchema.validate('VE9PTUFOWVNFQ1JFVFM='); // No Error

const paddingOptionalSchema = Joi.string().base64({ paddingRequired: false });
paddingOptionalSchema.validate('VE9PTUFOWVNFQ1JFVFM'); // No Error
paddingOptionalSchema.validate('VE9PTUFOWVNFQ1JFVFM='); // No Error

Possible validation errors: string.base64

string.dataUri([options])

Requires the string value to be a valid data URI string.

  • options - optional settings:
    • paddingRequired - optional parameter defaulting to true which will require = padding if true or make padding optional if false.
const schema = Joi.string().dataUri();
schema.validate('VE9PTUFOWVNFQ1JFVFM='); // ValidationError: "value" must be a valid dataUri string
schema.validate('data:image/png;base64,VE9PTUFOWVNFQ1JFVFM='); // No Error

Possible validation errors: string.dataUri

string.hostname()

Requires the string value to be a valid hostname as per RFC1123.

const schema = Joi.string().hostname();

Possible validation errors: string.hostname

string.normalize([form])

Requires the string value to be in a unicode normalized form. If the validation convert option is on (enabled by default), the string will be normalized.

  • form - The unicode normalization form to use. Valid values: NFC [default], NFD, NFKC, NFKD
const schema = Joi.string().normalize(); // defaults to NFC
const schema = Joi.string().normalize('NFC'); // canonical composition
const schema = Joi.string().normalize('NFD'); // canonical decomposition
const schema = Joi.string().normalize('NFKC'); // compatibility composition
const schema = Joi.string().normalize('NFKD'); // compatibility decomposition

Possible validation errors: string.normalize

string.lowercase()

Requires the string value to be all lowercase. If the validation convert option is on (enabled by default), the string will be forced to lowercase.

const schema = Joi.string().lowercase();

Possible validation errors: string.lowercase

string.uppercase()

Requires the string value to be all uppercase. If the validation convert option is on (enabled by default), the string will be forced to uppercase.

const schema = Joi.string().uppercase();

Possible validation errors: string.uppercase

string.trim([enabled])

Requires the string value to contain no whitespace before or after. If the validation convert option is on (enabled by default), the string will be trimmed.

Parameters are:

  • enabled - optional parameter defaulting to true which allows you to reset the behavior of trim by providing a falsy value.
const schema = Joi.string().trim();
const schema = Joi.string().trim(false); // disable trim flag

Possible validation errors: string.trim

string.isoDate()

Requires the string value to be in valid ISO 8601 date format.

If the validation convert option is on (enabled by default), the string will be forced to simplified extended ISO format (ISO 8601). Be aware that this operation uses javascript Date object, which does not support the full ISO format, so a few formats might not pass when using convert.

const schema = Joi.string().isoDate();
schema.validate('2018-11-28T18:25:32+00:00'); // No Error
schema.validate('20181-11-28T18:25:32+00:00'); // ValidationError: must be a valid 8601 date
schema.validate(''); // ValidationError: must be a valid 8601 date

Possible validation errors: string.isoDate

string.isoDuration()

Requires the string value to be in valid ISO 8601 duration format.

const schema = Joi.string().isoDuration();
schema.validate('P3Y6M4DT12H30M5S'); // No Error
schema.validate('2018-11-28T18:25:32+00:00'); // ValidationError: must be a valid ISO 8601 duration
schema.validate(''); // ValidationError: must be a valid ISO 8601 duration

Possible validation errors: string.isoDuration

symbol - inherits from Any

Generates a schema object that matches a Symbol data type.

If the validation convert option is on (enabled by default), the mappings declared in map() will be tried for an eventual match.

Supports the same methods of the any() type.

const schema = Joi.symbol().map({ 'foo': Symbol('foo'), 'bar': Symbol('bar') });
schema.validate('foo', (err, value) => { });

Possible validation errors: symbol.base

symbol.map(map)

Allows values to be transformed into Symbols, where:

  • map - mapping declaration that can be:
    • an object, where keys are strings, and values are Symbols
    • an array of arrays of length 2, where for each sub-array, the 1st element must be anything but an object, a function or a Symbol, and the 2nd element must be a Symbol
    • a Map, following the same principles as the array above
const schema = Joi.symbol().map([
    [1, Symbol('one')],
    ['two', Symbol('two')]
]);

Possible validation errors: symbol.map

alternatives - inherits from Any

Generates a type that will match one of the provided alternative schemas via the try() method. If no schemas are added, the type will not match any value except for undefined.

Supports the same methods of the any() type.

Alternatives can be expressed using the shorter [] notation.

const alt = Joi.alternatives().try([Joi.number(), Joi.string()]);
// Same as [Joi.number(), Joi.string()]

Possible validation errors: alternatives.base, alternatives.types, alternatives.match

alternatives.try(schemas)

Adds an alternative schema type for attempting to match against the validated value where:

  • schema - a single or an array of alternative joi types.
const alt = Joi.alternatives().try([Joi.number(), Joi.string()]);
alt.validate('a', (err, value) => { });

alternatives.when(condition, options)

Adds a conditional alternative schema type, either based on another key (not the same as any.when()) value, or a schema peeking into the current value, where:

  • condition - the key name or reference, or a schema.
  • options - an object with:
    • is - the condition expressed as a joi schema. Anything that is not a joi schema will be converted using Joi.compile.
    • then - if the condition is true, the joi schema to use.
    • otherwise - if the condition is false, the joi schema to use.
    • switch - an array of { is, then } conditions that are evaluated against the condition. The last item in the array may also contain otherwise.

If condition is a reference:

  • one of is or switch is required.
  • one of then, otherwise, or switch is required.
  • cannot use is or then with switch.
  • cannot specify otherwise both inside the last switch statement and outside.

If condition is a schema:

  • cannot specify is or switch.
  • one of then or otherwise is required.

Note that alternatives.when() is different than any.when(). When you use any.when() you end up with an alternatives type that is based on the base type when() was called on. Each then or otherwise is a concatenation of the base type with the other schemas. You cannot add additional conditions to such an alternatives type.

const schema = {
    a: Joi.alternatives().when('b', { is: 5, then: Joi.string(), otherwise: Joi.number() }),
    b: Joi.any()
};
const schema = Joi.alternatives().when(Joi.object({ b: 5 }).unknown(), {
    then: Joi.object({
        a: Joi.string(),
        b: Joi.any()
    }),
    otherwise: Joi.object({
        a: Joi.number(),
        b: Joi.any()
    })
});

Note that when() only adds additional alternatives to try and does not impact the overall type. Setting a required() rule on a single alternative will not apply to the overall key. For example, this definition of a:

const schema = {
    a: Joi.alternatives().when('b', { is: true, then: Joi.required() }),
    b: Joi.boolean()
};

Does not turn a into a required key when b is true. Instead, it tells the validator to try and match the value to anything that's not undefined. However, since Joi.alternatives() by itself allows undefined, the rule does not accomplish turning a to a required value. This rule is the same as Joi.alternatives([Joi.required()]) when b is true which will allow any value including undefined.

To accomplish the desired result above use:

const schema = {
    a: Joi.when('b', { is: true, then: Joi.required() }),
    b: Joi.boolean()
};

lazy(fn[, options]) - inherits from Any

Generates a placeholder schema for a schema that you would provide where:

  • fn - is a function returning the actual schema to use for validation.
  • options:
    • once - enables or disables the single evaluation behavior. When false, the function will be called every time a validation happens, otherwise the schema will be cached for further re-use. Defaults to true.

Supports the same methods of the any() type.

This is mostly useful for recursive schemas, like :

const Person = Joi.object({
    firstName: Joi.string().required(),
    lastName: Joi.string().required(),
    children: Joi.array().items(Joi.lazy(() => Person).description('Person schema'))
});

Possible validation errors: lazy.base, lazy.schema

Errors

joi throws ValidationErrors containing :

  • name - 'ValidationError'.
  • isJoi - true.
  • details - an array of errors :
    • message - string with a description of the error.
    • path - ordered array where each element is the accessor to the value where the error happened.
    • type - type of the error.
    • local - object providing context of the error containing:
      • key - key of the value that errored, equivalent to the last element of details.path.
      • label - label of the value that errored, or the key if any, or the default messages.root.
      • value - the value that failed validation.
      • other error specific properties as described for each error code.
  • annotate - function that returns a string with an annotated version of the object pointing at the places where errors occurred. Takes an optional parameter that, if truthy, will strip the colors out of the output.
  • _object - the original object to validate.

Check if an Error is a joi ValidationError like:

} catch (error) {
    if (error instanceof Joi.ValidationError) {
        // 400
    } else {
        // 500
    }
}

List of errors

alternatives.base

No alternative was found to test against the input due to try criteria.

alternatives.types

The provided input did not match any of the allowed types.

Additional local context properties:

{
    types: Array<string> // The list of expected types
}

alternatives.match

No alternative matched the input due to specific matching rules for at least one of the alternatives.

Additional local context properties:

{
    details: Array<object>, // An array of details for each error found while trying to match to each of the alternatives
    message: string // The combined error messages
}

any.allowOnly

Only some values were allowed, the input didn't match any of them.

Additional local context properties:

{
    valids: Array<any> // Contains the list of the valid values that were expected
}

any.default

If your any.default() generator function throws error, you will have it here.

Additional local context properties:

{
    error: Error // Error generated during the default value function call
}

any.failover

If your any.failover() generator function throws error, you will have it here.

Additional local context properties:

{
    error: Error // Error generated during the failover value function call
}

any.empty

When an empty string is found and denied by invalid values.

Additional local context properties:

{
    invalids: Array<any> // Contains the list of the invalid values that should be rejected
}

any.invalid

The value matched a value listed in the invalid values.

Additional local context properties:

{
    invalids: Array<any> // Contains the list of the invalid values that should be rejected
}

any.required

A required value wasn't present.

any.unknown

A value was present while it wasn't expected.

array.base

The value is not of Array type or could not be cast to an Array from a string.

array.excludes

The array contains a value that is part of the exclusion list.

Additional local context properties:

{
    pos: number // Index where the value was found in the array
}

array.includesRequiredBoth

Some values were expected to be present in the array and are missing. This error happens when we have a mix of labelled and unlabelled schemas.

Additional local context properties:

{
    knownMisses: Array<string>, // Labels of all the missing values
    unknownMisees: number // Count of missing values that didn't have a label
}

array.includesRequiredKnowns

Some values were expected to be present in the array and are missing. This error happens when we only have labelled schemas.

Additional local context properties:

{
    knownMisses: Array<string> // Labels of all the missing values
}

array.includesRequiredUnknowns

Some values were expected to be present in the array and are missing. This error happens when we only have unlabelled schemas.

Additional local context properties:

{
    unknownMisees: number // Count of missing values that didn't have a label
}

array.includes

The value didn't match any of the allowed types for that array.

Additional local context properties:

{
    pos: number // Index where the value was found in the array
}

array.length

The array is not of the expected length.

Additional local context properties:

{
    limit: number // Length that was expected for this array
}

array.max

The array has more elements than the maximum allowed.

Additional local context properties:

{
    limit: number // Maximum length that was expected for this array
}

array.min

The array has less elements than the minimum allowed.

Additional local context properties:

{
    limit: number // Minimum length that was expected for this array
}

array.orderedLength

Given an array.ordered(), that array has more elements than it should.

Additional local context properties:

{
    pos: number, // Index where the value was found in the array
    limit: number // Maximum length that was expected for this array
}

array.ref

A reference was used in one of array.min(), array.max() or array.length() and the value pointed to by that reference in the input is not a valid number for those rules.

Additional local context properties:

{
    ref: Reference // Reference used
}

array.sort

The array did not match the required sort order.

Additional local context properties:

{
    order: string, // 'ascending' or 'descending'
    by: string // The object key used for comparison
}

array.sort.mismatching

Failed sorting the array due to mismatching item types.

array.sort.unsupported

Failed sorting the array due to unsupported item types.

Additional local context properties:

{
    type: string // The unsupported array item type
}

array.sparse

An undefined value was found in an array that shouldn't be sparse.

Additional local context properties:

{
    pos: number // Index where an undefined value was found in the array
}

array.unique

A duplicate value was found in an array.

Additional local context properties:

{
    pos: number, // Index where the duplicate value was found in the array
    dupePos: number, // Index where the first appearance of the duplicate value was found in the array
    dupeValue: any // Value with which the duplicate was met
}

array.hasKnown

The schema on an array.has() was not found in the array. This error happens when the schema is labelled.

Additional local context properties:

{
    patternLabel: string // Label of assertion schema
}

array.hasUnknown

The schema on an array.has() was not found in the array. This error happens when the schema is unlabelled.

binary.base

The value is either not a Buffer or could not be cast to a Buffer from a string.

binary.length

The buffer was not of the specified length.

Additional local context properties:

{
    limit: number // Length that was expected for this buffer
}

binary.max

The buffer contains more bytes than expected.

Additional local context properties:

{
    limit: number // Maximum length that was expected for this buffer
}

binary.min

The buffer contains less bytes than expected.

Additional local context properties:

{
    limit: number // Minimum length that was expected for this buffer
}

binary.ref

A reference was used in one of binary.min(), binary.max(), binary.length() and the value pointed to by that reference in the input is not a valid number.

Additional local context properties:

{
    ref: Reference // Reference used
}

boolean.base

The value is either not a boolean or could not be cast to a boolean from one of the truthy or falsy values.

date.base

The value is either not a date or could not be cast to a date from a string or a number.

date.greater

The date is over the limit that you set.

Additional local context properties:

{
    limit: Date // Maximum date
}

date.isoDate

The date does not match the ISO 8601 format.

date.less

The date is under the limit that you set.

Additional local context properties:

{
    limit: Date // Minimum date
}

date.max

The date is over or equal to the limit that you set.

Additional local context properties:

{
    limit: Date // Maximum date
}

date.min

The date is under or equal to the limit that you set.

Additional local context properties:

{
    limit: Date // Minimum date
}

date.ref

A reference was used in one of date.min(), date.max(), date.less() or date.greater() and the value pointed to by that reference in the input is not a valid date.

Additional local context properties:

{
    ref: Reference // Reference used
}

date.strict

Occurs when the input is not a Date type and convert is disabled.

date.timestamp.javascript

Failed to be converted from a string or a number to a date as JavaScript timestamp.

date.timestamp.unix

Failed to be converted from a string or a number to a date as Unix timestamp.

function.arity

The number of arguments for the function doesn't match the required number.

Additional local context properties:

{
    n: number // Expected arity
}

function.base

The input is not a function.

function.class

The input is not a JavaScript class.

function.maxArity

The number of arguments for the function is over the required number.

Additional local context properties:

{
    n: number // Maximum expected arity
}

function.minArity

The number of arguments for the function is under the required number.

Additional local context properties:

{
    n: number // Minimum expected arity
}

lazy.base

The lazy function is not set.

lazy.schema

The lazy function didn't return a joi schema.

Additional local context properties:

{
    schema: any // The value return by the generator function
}

number.base

The value is not a number or could not be cast to a number.

number.greater

The number is lower or equal to the limit that you set.

Additional local context properties:

{
    limit: number // Minimum value that was expected for this number
}

number.integer

The number is not a valid integer.

number.less

The number is higher or equal to the limit that you set.

Additional local context properties:

{
    limit: number // Maximum value that was expected for this number
}

number.max

The number is higher than the limit that you set.

Additional local context properties:

{
    limit: number // Maximum value that was expected for this number
}

number.min

The number is lower than the limit that you set.

Additional local context properties:

{
    limit: number // Minimum value that was expected for this number
}

number.multiple

The number could not be divided by the multiple you provided.

Additional local context properties:

{
    multiple: number // The number of which the input is supposed to be a multiple of
}

number.negative

The number was positive.

number.port

The number didn't look like a port number.

number.positive

The number was negative.

number.precision

The number didn't have the required precision.

Additional local context properties:

{
    limit: number // The precision that it should have had
}

number.ref

A reference was used in one of number.min(), number.max(), number.less(), number.greater(), or number.multiple() and the value pointed to by that reference in the input is not a valid number.

number.unsafe

The number is not within the safe range of JavaScript numbers.

object.allowUnknown

An unexpected property was found in the object.

Additional local context properties:

{
    child: string // Property that is unexpected
}

object.and

The AND condition between the properties you specified was not satisfied in that object.

Additional local context properties:

{
    present: Array<string>, // List of properties that are set
    presentWithLabels: Array<string>, // List of labels for the properties that are set
    missing: Array<string>, // List of properties that are not set
    missingWithLabels: Array<string> // List of labels for the properties that are not set
}

object.assert

The schema on an object.assert() failed to validate.

Additional local context properties:

{
    ref: string, // Dotted path to the property that was checked
    message: string // Custom message or default one
}

object.base

The value is not of object type or could not be cast to an object from a string.

object.length

The number of keys for this object is not of the expected length.

Additional local context properties:

{
    limit: number // Number of keys that was expected for this object
}

object.max

The number of keys for this object is over or equal to the limit that you set.

Additional local context properties:

{
    limit: number // Maximum number of keys
}

object.min

The number of keys for this object is under or equal to the limit that you set.

Additional local context properties:

{
    limit: number // Minimum number of keys
}

object.missing

The OR or XOR condition between the properties you specified was not satisfied in that object, none of it were set.

Additional local context properties:

{
    peers: Array<string>, // List of properties were none of it was set
    peersWithLabels: Array<string> // List of labels for the properties were none of it was set
}

object.nand

The NAND condition between the properties you specified was not satisfied in that object.

Additional local context properties:

{
    main: string, // One of the properties that was present
    mainWithLabel: string, // The label of the `main` property
    peers: Array<string>, // List of the other properties that were present
    peersWithLabels: Array<string> // List of the labels of the other properties that were present
}

object.ref

A reference was used in one of object.min(), object.max(), object.length() and the value pointed to by that reference in the input is not a valid number.

Additional local context properties:

{
    ref: Reference // Reference used
}

object.refType

The object is not a Joi.ref().

object.rename.multiple

Another rename was already done to the same target property.

Additional local context properties:

{
    from: string, // Origin property name of the rename
    to: string, // Target property of the rename
    pattern: boolean // Indicates if the rename source was a pattern (regular expression)
}

object.rename.override

The target property already exists and you disallowed overrides.

Additional local context properties:

{
    from: string, // Origin property name of the rename
    to: string, // Target property of the rename
    pattern: boolean // Indicates if the rename source was a pattern (regular expression)
}

object.schema

The object was not a joi schema.

Additional local context properties:

{
    type: string // The required schema
}

object.type

The object is not of the type you specified.

Additional local context properties:

{
    type: string // Type name the object should have been
}

object.with

Property that should have been present at the same time as another one was missing.

Additional local context properties:

{
    main: string, // Property that triggered the check
    mainWithLabel: string, // Label of the property that triggered the check
    peer: string, // Property that was missing
    peerWithLabels: string // Label of the other property that was missing
}

object.without

Property that should have been absent at the same time as another one was present.

Additional local context properties:

{
    main: string, // Property that triggered the check
    mainWithLabel: string, // Label of the property that triggered the check
    peer: string, // Property that was present
    peerWithLabels: string // Label of the other property that was present
}

object.xor

The XOR condition between the properties you specified was not satisfied in that object.

Additional local context properties:

{
    peers: Array<string>, // List of properties where none of it or too many of it was set
    peersWithLabels: Array<string> // List of labels for the properties where none of it or too many of it was set
}

object.oxor

The optional XOR condition between the properties you specified was not satisfied in that object.

Additional local context properties:

{
    peers: Array<string>, // List of properties where too many of it was set
    peersWithLabels: Array<string> // List of labels for the properties where too many of it was set
}

string.alphanum

The string doesn't only contain alphanumeric characters.

string.base64

The string isn't a valid base64 string.

string.base

The input is not a string.

string.creditCard

The string is not a valid credit card number.

string.dataUri

The string is not a valid data URI.

string.domain

The string is not a valid domain name.

string.email

The string is not a valid e-mail.

Additional local context properties:

{
    invalids: [string] // Array of invalid emails
}

string.guid

The string is not a valid GUID.

string.hexAlign

The string contains hexadecimal characters but they are not byte-aligned.

string.hex

The string is not a valid hexadecimal string.

string.hostname

The string is not a valid hostname.

string.ipVersion

The string is not a valid IP address considering the provided constraints.

Additional local context properties:

{
    cidr: string, // CIDR used for the validation
    version: Array<string> // List of IP version accepted
}

string.ip

The string is not a valid IP address.

Additional local context properties:

{
    cidr: string // CIDR used for the validation
}

string.isoDate

The string is not a valid ISO date string.

string.isoDuration

The string must be a valid ISO 8601 duration.

string.length

The string is not of the expected length.

Additional local context properties:

{
    limit: number, // Length that was expected for this string
    encoding: undefined | string // Encoding specified for the check if any
}

string.lowercase

The string isn't all lower-cased.

string.max

The string is larger than expected.

Additional local context properties:

{
    limit: number, // Maximum length that was expected for this string
    encoding: undefined | string // Encoding specified for the check if any
}

string.min

The string is smaller than expected.

Additional local context properties:

{
    limit: number, // Minimum length that was expected for this string
    encoding: undefined | string // Encoding specified for the check if any
}

string.normalize

The string isn't valid in regards of the normalization form expected.

Additional local context properties:

{
    form: string // Normalization form that is expected
}

string.ref

A reference was used in one of string.min(), string.max() or string.length() and the value pointed to by that reference in the input is not a valid number for those rules.

Additional local context properties:

{
    ref: Reference // Reference used
}

string.regex.base

The string didn't match the regular expression.

Additional local context properties:

{
    name: undefined, // Undefined since the regular expression has no name
    pattern: string // Regular expression
}

string.regex.name

The string didn't match the named regular expression.

Additional local context properties:

{
    name: string, // Name of the regular expression
    pattern: string // Regular expression
}

string.regex.invert.base

The string matched the regular expression while it shouldn't.

Additional local context properties:

{
    name: undefined, // Undefined since the regular expression has no name
    pattern: string // Regular expression
}

string.regex.invert.name

The string matched the named regular expression while it shouldn't.

Additional local context properties:

{
    name: string, // Name of the regular expression
    pattern: string // Regular expression
}

string.token

The string isn't a token.

string.trim

The string contains whitespaces around it.

string.uppercase

The string isn't all upper-cased.

string.uri

The string isn't a valid URI.

string.uriCustomScheme

The string isn't a valid URI considering the custom schemes.

Additional local context properties:

{
    scheme: string // Scheme prefix that is expected in the URI
}

string.uriRelativeOnly

The string is a valid relative URI.

symbol.base

The input is not a Symbol.

symbol.map

The input is not a Symbol or could not be converted to one.