Require Node.js 8, add TypeScript definition (#4)

.editorconfig

@@ -7,6 +7,6 @@ charset = utf-8
 trim_trailing_whitespace = true
 insert_final_newline = true
 
-[{package.json,*.yml}]
+[*.yml]
 indent_style = space
 indent_size = 2

.gitattributes

@@ -1,2 +1 @@
-* text=auto
-*.js text eol=lf
+* text=auto eol=lf

.gitignore

@@ -1 +1,2 @@
 node_modules
+yarn.lock

.npmrc

@@ -0,0 +1 @@
+package-lock=false

.travis.yml

@@ -1,4 +1,4 @@
 language: node_js
 node_js:
- - '6'
- - '4'
+ - '10'
+ - '8'

index.d.ts

@@ -0,0 +1,17 @@
+/**
+ * Conditional promise chains. It's just a passthrough if `condition` is `false` and `doElse` is not provided.
+ *
+ * @param condition - Decides whether `doIf` or `doElse` is executed.
+ * @param doIf - Executed if `condition` is `true`. Expected to return a `Promise` or value.
+ * @param doElse - Executed if `condition` is `false`. Expected to return a `Promise` or value.
+ * @returns A [thunk](https://en.m.wikipedia.org/wiki/Thunk) that returns a `Promise`.
+ */
+export default function pIf<
+ ValueType,
+ DoIfReturnType,
+ DoElseReturnType = ValueType
+>(
+ condition: boolean | ((value: ValueType) => boolean | PromiseLike<boolean>),
+ doIf: (value: ValueType) => DoIfReturnType | PromiseLike<DoIfReturnType>,
+ doElse?: (value: ValueType) => DoElseReturnType | PromiseLike<DoElseReturnType>
+): (value: ValueType) => Promise<DoIfReturnType | DoElseReturnType>;

index.js

@@ -1,12 +1,16 @@
 'use strict';
 
-module.exports = (cond, doIf, doElse) => val => {
- const chooseFn = bool => bool === true ? doIf(val) : (doElse ? doElse(val) : val);
+const pIf = (condition, doIf, doElse) => async value => {
+ const chooseFn = bool =>
+ bool === true ? doIf(value) : doElse ? doElse(value) : value;
 
- if (typeof cond === 'function') {
- return Promise.resolve(cond(val)).then(chooseFn);
+ if (typeof condition === 'function') {
+ const conditionResult = await condition(value);
+ return chooseFn(conditionResult);
  }
 
- return chooseFn(cond);
+ return chooseFn(condition);
 };
 
+module.exports = pIf;
+module.exports.default = pIf;

index.test-d.ts

@@ -0,0 +1,106 @@
+import {expectType} from 'tsd-check';
+import pIf from '.';
+
+expectType<Promise<number | string>>(
+ pIf<number, string>(true, value => {
+ expectType<number>(value);
+ return 'foo';
+ })(1)
+);
+expectType<Promise<number | string>>(
+ pIf<number, string>(
+ value => {
+ expectType<number>(value);
+ return true;
+ },
+ value => {
+ expectType<number>(value);
+ return 'foo';
+ }
+ )(1)
+);
+expectType<Promise<number | string>>(
+ pIf<number, string>(
+ value => {
+ expectType<number>(value);
+ return Promise.resolve(true);
+ },
+ value => {
+ expectType<number>(value);
+ return 'foo';
+ }
+ )(1)
+);
+expectType<Promise<number | string>>(
+ pIf<number, string>(
+ value => {
+ expectType<number>(value);
+ return Promise.resolve(true);
+ },
+ value => {
+ expectType<number>(value);
+ return Promise.resolve('foo');
+ }
+ )(1)
+);
+expectType<Promise<symbol | string>>(
+ pIf<number, string, symbol>(
+ true,
+ value => {
+ expectType<number>(value);
+ return 'foo';
+ },
+ value => {
+ expectType<number>(value);
+ return Symbol();
+ }
+ )(1)
+);
+expectType<Promise<symbol | string>>(
+ pIf<number, string, symbol>(
+ value => {
+ expectType<number>(value);
+ return true;
+ },
+ value => {
+ expectType<number>(value);
+ return 'foo';
+ },
+ value => {
+ expectType<number>(value);
+ return Symbol();
+ }
+ )(1)
+);
+expectType<Promise<number | string | symbol>>(
+ pIf<number, string, symbol>(
+ value => {
+ expectType<number>(value);
+ return Promise.resolve(true);
+ },
+ value => {
+ expectType<number>(value);
+ return 'foo';
+ },
+ value => {
+ expectType<number>(value);
+ return Symbol();
+ }
+ )(1)
+);
+expectType<Promise<symbol | string>>(
+ pIf<number, string, symbol>(
+ value => {
+ expectType<number>(value);
+ return Promise.resolve(true);
+ },
+ value => {
+ expectType<number>(value);
+ return Promise.resolve('foo');
+ },
+ value => {
+ expectType<number>(value);
+ return Promise.resolve(Symbol());
+ }
+ )(1)
+);

package.json

@@ -1,44 +1,43 @@
 {
- "name": "p-if",
- "version": "1.1.0",
- "description": "Conditional promise chains",
- "license": "MIT",
- "repository": "sindresorhus/p-if",
- "author": {
- "name": "Sindre Sorhus",
- "email": "[email protected]",
- "url": "sindresorhus.com"
- },
- "engines": {
- "node": ">=4"
- },
- "scripts": {
- "test": "xo && ava"
- },
- "files": [
- "index.js"
- ],
- "keywords": [
- "promise",
- "if",
- "else",
- "conditional",
- "cond",
- "iff",
- "chain",
- "thunk",
- "function",
- "async",
- "await",
- "promises",
- "combinator",
- "bluebird"
- ],
- "devDependencies": {
- "ava": "*",
- "xo": "*"
- },
- "xo": {
- "esnext": true
- }
+ "name": "p-if",
+ "version": "1.1.0",
+ "description": "Conditional promise chains",
+ "license": "MIT",
+ "repository": "sindresorhus/p-if",
+ "author": {
+ "name": "Sindre Sorhus",
+ "email": "[email protected]",
+ "url": "sindresorhus.com"
+ },
+ "engines": {
+ "node": ">=8"
+ },
+ "scripts": {
+ "test": "xo && ava && tsd-check"
+ },
+ "files": [
+ "index.js",
+ "index.d.ts"
+ ],
+ "keywords": [
+ "promise",
+ "if",
+ "else",
+ "conditional",
+ "cond",
+ "iff",
+ "chain",
+ "thunk",
+ "function",
+ "async",
+ "await",
+ "promises",
+ "combinator",
+ "bluebird"
+ ],
+ "devDependencies": {
+ "ava": "^1.3.1",
+ "tsd-check": "^0.3.0",
+ "xo": "^0.24.0"
+ }
 }

test.js

@@ -1,56 +1,56 @@
 import test from 'ava';
-import m from './';
+import pIf from '.';
 
 const fixture = Symbol('fixture');
 
 test('if', async t => {
- const val = await Promise.resolve(fixture)
- .then(m(true, () => 'if', () => 'else'));
+ const value = await Promise.resolve(fixture)
+ .then(pIf(true, () => 'if', () => 'else'));
 
- t.is(val, 'if');
+ t.is(value, 'if');
 });
 
 test('else', async t => {
- const val = await Promise.resolve(fixture)
- .then(m(false, () => 'if', () => 'else'));
+ const value = await Promise.resolve(fixture)
+ .then(pIf(false, () => 'if', () => 'else'));
 
- t.is(val, 'else');
+ t.is(value, 'else');
 });
 
 test('passthrough', async t => {
- const val = await Promise.resolve(fixture)
- .then(m(false, () => 'if'));
+ const value = await Promise.resolve(fixture)
+ .then(pIf(false, () => 'if'));
 
- t.is(val, fixture);
+ t.is(value, fixture);
 });
 
 test('composability', async t => {
- const val = await Promise.resolve(fixture)
- .then(m(true, m(false, () => 'if', () => 'else')));
+ const value = await Promise.resolve(fixture)
+ .then(pIf(true, pIf(false, () => 'if', () => 'else')));
 
- t.is(val, 'else');
+ t.is(value, 'else');
 });
 
 test('condition can be a function', async t => {
  const isEmpty = arr => arr.length === 0;
 
- const valA = await Promise.resolve([])
- .then(m(isEmpty, arr => arr.concat(42)));
+ const valueA = await Promise.resolve([])
+ .then(pIf(isEmpty, arr => arr.concat(42)));
 
- const valB = await Promise.resolve([1])
- .then(m(isEmpty, arr => arr.concat(42)));
+ const valueB = await Promise.resolve([1])
+ .then(pIf(isEmpty, arr => arr.concat(42)));
 
- t.deepEqual(valA, [42]);
- t.deepEqual(valB, [1]);
+ t.deepEqual(valueA, [42]);
+ t.deepEqual(valueB, [1]);
 });
 
 test('condition can be an async function', async t => {
- const valA = await Promise.resolve([])
- .then(m(async () => true, arr => arr.concat(42)));
+ const valueA = await Promise.resolve([])
+ .then(pIf(async () => true, arr => arr.concat(42)));
 
- const valB = await Promise.resolve([1])
- .then(m(async () => false, arr => arr.concat(42)));
+ const valueB = await Promise.resolve([1])
+ .then(pIf(async () => false, arr => arr.concat(42)));
 
- t.deepEqual(valA, [42]);
- t.deepEqual(valB, [1]);
+ t.deepEqual(valueA, [42]);
+ t.deepEqual(valueB, [1]);
 });