Enable @typescript-eslint/strict-boolean-expressions rule

.eslintrc.cjs

@@ -605,7 +605,10 @@ module.exports = {
  '@typescript-eslint/restrict-plus-operands': 'off', // TODO: temporarily disabled
  '@typescript-eslint/restrict-template-expressions': 'off', // TODO: temporarily disabled
  '@typescript-eslint/sort-type-union-intersection-members': 'off', // TODO: consider
- '@typescript-eslint/strict-boolean-expressions': 'off', // TODO: consider
+ '@typescript-eslint/strict-boolean-expressions': [
+ 'error',
+ { allowNullableBoolean: true }, // TODO: consider removing
+ ],
  '@typescript-eslint/switch-exhaustiveness-check': 'error',
  '@typescript-eslint/triple-slash-reference': 'error',
  '@typescript-eslint/typedef': 'off',

resources/gen-changelog.ts

@@ -33,7 +33,7 @@ const labelsConfig: { [label: string]: { section: string; fold?: boolean } } = {
 };
 const { GH_TOKEN } = process.env;
 
-if (!GH_TOKEN) {
+if (GH_TOKEN == null) {
  console.error('Must provide GH_TOKEN as environment variable!');
  process.exit(1);
 }
@@ -88,7 +88,7 @@ async function genChangeLog(): Promise<string> {
  }
 
  const label = labels[0];
- if (!labelsConfig[label]) {
+ if (labelsConfig[label] != null) {
  throw new Error(`Unknown label: ${label}. See ${pr.url}`);
  }
  byLabel[label] ??= [];
@@ -99,7 +99,7 @@ async function genChangeLog(): Promise<string> {
  let changelog = `## ${tag ?? 'Unreleased'} (${date})\n`;
  for (const [label, config] of Object.entries(labelsConfig)) {
  const prs = byLabel[label];
- if (prs) {
+ if (prs != null) {
  const shouldFold = config.fold && prs.length > 1;
 
  changelog += `\n#### ${config.section}\n`;
@@ -149,7 +149,7 @@ async function graphqlRequest(query: string) {
  }
 
  const json = await response.json();
- if (json.errors) {
+ if (json.errors != null) {
  throw new Error('Errors: ' + JSON.stringify(json.errors, null, 2));
  }
  return json.data;

src/error/GraphQLError.ts

@@ -141,13 +141,13 @@ export class GraphQLError extends Error {
  // Include (non-enumerable) stack trace.
  /* c8 ignore start */
  // FIXME: https:/graphql/graphql-js/issues/2317
- if (originalError?.stack) {
+ if (originalError?.stack != null) {
  Object.defineProperty(this, 'stack', {
  value: originalError.stack,
  writable: true,
  configurable: true,
  });
- } else if (Error.captureStackTrace) {
+ } else if (Error.captureStackTrace != null) {
  Error.captureStackTrace(this, GraphQLError);
  } else {
  Object.defineProperty(this, 'stack', {

src/execution/__tests__/abstract-test.ts

@@ -19,6 +19,10 @@ import { buildSchema } from '../../utilities/buildASTSchema.js';
 
 import { execute, executeSync } from '../execute.js';
 
+interface Context {
+ async: boolean;
+}
+
 async function executeQuery(args: {
  schema: GraphQLSchema;
  query: string;
@@ -30,13 +34,13 @@ async function executeQuery(args: {
  schema,
  document,
  rootValue,
- contextValue: { async: false },
+ contextValue: { async: false } satisfies Context,
  });
  const asyncResult = await execute({
  schema,
  document,
  rootValue,
- contextValue: { async: true },
+ contextValue: { async: true } satisfies Context,
  });
 
  expectJSON(result).toDeepEqual(asyncResult);
@@ -72,7 +76,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const DogType = new GraphQLObjectType({
+ const DogType = new GraphQLObjectType<Dog, { async: boolean }>({
  name: 'Dog',
  interfaces: [PetType],
  isTypeOf(obj, context) {
@@ -85,7 +89,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const CatType = new GraphQLObjectType({
+ const CatType = new GraphQLObjectType<Cat, { async: boolean }>({
  name: 'Cat',
  interfaces: [PetType],
  isTypeOf(obj, context) {
@@ -151,7 +155,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const DogType = new GraphQLObjectType({
+ const DogType = new GraphQLObjectType<Dog, Context>({
  name: 'Dog',
  interfaces: [PetType],
  isTypeOf(_source, context) {
@@ -167,7 +171,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const CatType = new GraphQLObjectType({
+ const CatType = new GraphQLObjectType<Cat, Context>({
  name: 'Cat',
  interfaces: [PetType],
  isTypeOf: undefined,
@@ -233,7 +237,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const DogType = new GraphQLObjectType({
+ const DogType = new GraphQLObjectType<Dog, Context>({
  name: 'Dog',
  interfaces: [PetType],
  isTypeOf(_source, context) {
@@ -280,7 +284,7 @@ describe('Execute: Handles execution of abstract types', () => {
  });
 
  it('isTypeOf used to resolve runtime type for Union', async () => {
- const DogType = new GraphQLObjectType({
+ const DogType = new GraphQLObjectType<Dog, Context>({
  name: 'Dog',
  isTypeOf(obj, context) {
  const isDog = obj instanceof Dog;
@@ -292,7 +296,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const CatType = new GraphQLObjectType({
+ const CatType = new GraphQLObjectType<Cat, Context>({
  name: 'Cat',
  isTypeOf(obj, context) {
  const isCat = obj instanceof Cat;
@@ -357,7 +361,7 @@ describe('Execute: Handles execution of abstract types', () => {
  name: 'Pet',
  resolveType(_source, context) {
  const error = new Error('We are testing this error');
- if (context.async) {
+ if (context.async === true) {
  return Promise.reject(error);
  }
  throw error;
@@ -367,7 +371,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const DogType = new GraphQLObjectType({
+ const DogType = new GraphQLObjectType<Dog, Context>({
  name: 'Dog',
  interfaces: [PetType],
  fields: {
@@ -376,7 +380,7 @@ describe('Execute: Handles execution of abstract types', () => {
  },
  });
 
- const CatType = new GraphQLObjectType({
+ const CatType = new GraphQLObjectType<Cat, Context>({
  name: 'Cat',
  interfaces: [PetType],
  fields: {

src/execution/__tests__/executor-test.ts

@@ -1143,11 +1143,11 @@ describe('Execute: Handles basic execution tasks', () => {
  }
  }
 
- const SpecialType = new GraphQLObjectType({
+ const SpecialType = new GraphQLObjectType<Special, { async: boolean }>({
  name: 'SpecialType',
  isTypeOf(obj, context) {
  const result = obj instanceof Special;
- return context?.async ? Promise.resolve(result) : result;
+ return context.async ? Promise.resolve(result) : result;
  },
  fields: { value: { type: GraphQLString } },
  });
@@ -1166,7 +1166,12 @@ describe('Execute: Handles basic execution tasks', () => {
  specials: [new Special('foo'), new NotSpecial('bar')],
  };
 
- const result = executeSync({ schema, document, rootValue });
+ const result = executeSync({
+ schema,
+ document,
+ rootValue,
+ contextValue: { async: false },
+ });
  expectJSON(result).toDeepEqual({
  data: {
  specials: [{ value: 'foo' }, null],
@@ -1181,12 +1186,11 @@ describe('Execute: Handles basic execution tasks', () => {
  ],
  });
 
- const contextValue = { async: true };
  const asyncResult = await execute({
  schema,
  document,
  rootValue,
- contextValue,
+ contextValue: { async: true },
  });
  expect(asyncResult).to.deep.equal(result);
  });

src/execution/__tests__/stream-test.ts

@@ -1839,7 +1839,7 @@ describe('Execute: stream directive', () => {
  [Symbol.asyncIterator]: () => ({
  next: () => {
  const friend = friends[index++];
- if (!friend) {
+ if (friend == null) {
  return Promise.resolve({ done: true, value: undefined });
  }
  return Promise.resolve({ done: false, value: friend });
@@ -1898,7 +1898,7 @@ describe('Execute: stream directive', () => {
  [Symbol.asyncIterator]: () => ({
  next: () => {
  const friend = friends[index++];
- if (!friend) {
+ if (friend == null) {
  return Promise.resolve({ done: true, value: undefined });
  }
  return Promise.resolve({ done: false, value: friend });
@@ -1954,7 +1954,7 @@ describe('Execute: stream directive', () => {
  [Symbol.asyncIterator]: () => ({
  next: () => {
  const friend = friends[index++];
- if (!friend) {
+ if (friend == null) {
  return Promise.resolve({ done: true, value: undefined });
  }
  return Promise.resolve({ done: false, value: friend });

src/execution/collectFields.ts

@@ -191,7 +191,7 @@ function collectFieldsImpl(
 
  const fragment = fragments[fragName];
  if (
- !fragment ||
+ fragment == null ||
  !doesFragmentConditionMatch(schema, fragment, runtimeType)
  ) {
  continue;

src/execution/execute.ts

@@ -2082,7 +2082,7 @@ function getCompletedIncrementalResults(
  }
 
  incrementalResult.path = asyncPayloadRecord.path;
- if (asyncPayloadRecord.label) {
+ if (asyncPayloadRecord.label != null) {
  incrementalResult.label = asyncPayloadRecord.label;
  }
  if (asyncPayloadRecord.errors.length > 0) {

src/execution/values.ts

@@ -1,5 +1,4 @@
 import { inspect } from '../jsutils/inspect.js';
-import { keyMap } from '../jsutils/keyMap.js';
 import type { Maybe } from '../jsutils/Maybe.js';
 import type { ObjMap } from '../jsutils/ObjMap.js';
 import { printPathArray } from '../jsutils/printPathArray.js';
@@ -159,14 +158,14 @@ export function getArgumentValues(
  // FIXME: https:/graphql/graphql-js/issues/2203
  /* c8 ignore next */
  const argumentNodes = node.arguments ?? [];
- const argNodeMap = keyMap(argumentNodes, (arg) => arg.name.value);
+ const argNodeMap = new Map(argumentNodes.map((arg) => [arg.name.value, arg]));
 
  for (const argDef of def.args) {
  const name = argDef.name;
  const argType = argDef.type;
- const argumentNode = argNodeMap[name];
+ const argumentNode = argNodeMap.get(name);
 
- if (!argumentNode) {
+ if (argumentNode == null) {
  if (argDef.defaultValue !== undefined) {
  coercedValues[name] = argDef.defaultValue;
  } else if (isNonNullType(argType)) {

src/jsutils/didYouMean.ts

@@ -23,7 +23,7 @@ export function didYouMean(
  }
 
  let message = ' Did you mean ';
- if (subMessage) {
+ if (subMessage != null) {
  message += subMessage + ' ';
  }
 

src/language/printer.ts

@@ -143,7 +143,8 @@ const printDocASTReducer: ASTReducer<string> = {
  FloatValue: { leave: ({ value }) => value },
  StringValue: {
  leave: ({ value, block: isBlockString }) =>
- isBlockString ? printBlockString(value) : printString(value),
+ // @ts-expect-error FIXME: it's a problem with ASTReducer, will be fixed in separate PR
+ isBlockString === true ? printBlockString(value) : printString(value),
  },
  BooleanValue: { leave: ({ value }) => (value ? 'true' : 'false') },
  NullValue: { leave: () => 'null' },

src/language/visitor.ts

@@ -234,7 +234,7 @@ export function visit(
  edits = stack.edits;
  inArray = stack.inArray;
  stack = stack.prev;
- } else if (parent) {
+ } else if (parent != null) {
  key = inArray ? index : keys[index];
  node = parent[key];
  if (node === null || node === undefined) {
@@ -287,7 +287,7 @@ export function visit(
  keys = inArray ? node : (visitorKeys as any)[node.kind] ?? [];
  index = -1;
  edits = [];
- if (parent) {
+ if (parent != null) {
  ancestors.push(parent);
  }
  parent = node;

src/type/__tests__/enumType-test.ts

@@ -71,12 +71,12 @@ const QueryType = new GraphQLObjectType({
  provideBadValue: { type: GraphQLBoolean },
  },
  resolve(_source, { fromEnum, provideGoodValue, provideBadValue }) {
- if (provideGoodValue) {
+ if (provideGoodValue === true) {
  // Note: this is one of the references of the internal values which
  // ComplexEnum allows.
  return Complex2;
  }
- if (provideBadValue) {
+ if (provideBadValue === true) {
  // Note: similar shape, but not the same *reference*
  // as Complex2 above. Enum internal values require === equality.
  return { someRandomValue: 123 };

src/type/introspection.ts

@@ -112,7 +112,7 @@ export const __Directive: GraphQLObjectType = new GraphQLObjectType({
  },
  },
  resolve(field, { includeDeprecated }) {
- return includeDeprecated
+ return includeDeprecated === true
  ? field.args
  : field.args.filter((arg) => arg.deprecationReason == null);
  },
@@ -266,7 +266,7 @@ export const __Type: GraphQLObjectType = new GraphQLObjectType({
  resolve(type, { includeDeprecated }) {
  if (isObjectType(type) || isInterfaceType(type)) {
  const fields = Object.values(type.getFields());
- return includeDeprecated
+ return includeDeprecated === true
  ? fields
  : fields.filter((field) => field.deprecationReason == null);
  }
@@ -296,7 +296,7 @@ export const __Type: GraphQLObjectType = new GraphQLObjectType({
  resolve(type, { includeDeprecated }) {
  if (isEnumType(type)) {
  const values = type.getValues();
- return includeDeprecated
+ return includeDeprecated === true
  ? values
  : values.filter((field) => field.deprecationReason == null);
  }
@@ -313,7 +313,7 @@ export const __Type: GraphQLObjectType = new GraphQLObjectType({
  resolve(type, { includeDeprecated }) {
  if (isInputObjectType(type)) {
  const values = Object.values(type.getFields());
- return includeDeprecated
+ return includeDeprecated === true
  ? values
  : values.filter((field) => field.deprecationReason == null);
  }
@@ -351,7 +351,7 @@ export const __Field: GraphQLObjectType = new GraphQLObjectType({
  },
  },
  resolve(field, { includeDeprecated }) {
- return includeDeprecated
+ return includeDeprecated === true
  ? field.args
  : field.args.filter((arg) => arg.deprecationReason == null);
  },

src/type/validate.ts

@@ -373,7 +373,7 @@ function validateTypeImplementsInterface(
  const typeField = typeFieldMap[fieldName];
 
  // Assert interface field exists on type.
- if (!typeField) {
+ if (typeField == null) {
  context.reportError(
  `Interface field ${iface.name}.${fieldName} expected but ${type.name} does not provide it.`,
  [ifaceField.astNode, type.astNode, ...type.extensionASTNodes],