Merge pull request #6 from github/add-string-replaceall

add string#replaceAll

Author: keithamus

src/index.ts

@@ -36,7 +36,7 @@ const baseSupport =
   //'allSettled' in Promise && // Polyfilled
   'matchAll' in String.prototype &&
   // ES2021
-  'replaceAll' in String.prototype &&
+  //'replaceAll' in String.prototype && // Polyfilled
   // 'any' in Promise && // Polyfilled
   // ES2022
   // 'at' in String.prototype && // Polyfilled

src/string-replaceall.ts

@@ -0,0 +1,38 @@
+export function stringReplaceAll(
+  this: string,
+  searchValue: RegExp | string,
+  replaceValue: ((substring: string, ...args: unknown[]) => string) | string
+): string {
+  if (searchValue instanceof RegExp) return this.replace(searchValue, replaceValue as unknown as string)
+  let pos = -1
+  let endOfLastMatch = 0
+  let result = ''
+  if (typeof replaceValue === 'function') {
+    const unwrapped = replaceValue
+    replaceValue = () => unwrapped(searchValue, pos, this)
+  }
+  pos = this.indexOf(searchValue, pos + 1)
+  while (pos !== -1) {
+    result += this.substring(endOfLastMatch, pos)
+    result += searchValue.replace(searchValue, replaceValue as string)
+    endOfLastMatch = pos + searchValue.length
+    pos = this.indexOf(searchValue, pos + 1)
+  }
+  return result + this.substring(endOfLastMatch)
+}
+
+/*#__PURE__*/
+export function isSupported(): boolean {
+  return 'replaceAll' in String.prototype && typeof String.prototype.replaceAll === 'function'
+}
+
+/*#__PURE__*/
+export function isPolyfilled(): boolean {
+  return String.prototype.replaceAll === stringReplaceAll
+}
+
+export function apply(): void {
+  if (!isSupported()) {
+    String.prototype.replaceAll = stringReplaceAll
+  }
+}

test/string-replaceall.js

@@ -0,0 +1,19 @@
+import {apply, isPolyfilled, isSupported, stringReplaceAll} from '../lib/string-replaceall.js'
+
+describe('String#replaceAll', () => {
+  it('has standard isSupported, isPolyfilled, apply API', () => {
+    expect(isSupported).to.be.a('function')
+    expect(isPolyfilled).to.be.a('function')
+    expect(apply).to.be.a('function')
+    expect(isSupported()).to.be.a('boolean')
+    expect(isPolyfilled()).to.equal(false)
+  })
+
+  it('replaces all ocurrences of a string', async () => {
+    expect(stringReplaceAll.call('aaa', 'a', 'bbb')).to.equal('bbbbbbbbb')
+    expect(stringReplaceAll.call('aaa', 'a', 'aba')).to.equal('abaabaaba')
+    expect(stringReplaceAll.call('_a_a_a_', 'a', 'b')).to.equal('_b_b_b_')
+    expect(stringReplaceAll.call('aaa', 'a', (match, i, whole) => match + i + whole)).to.equal('a0aaaa1aaaa2aaa')
+    expect(stringReplaceAll.call('aaa', /a/g, 'bbb')).to.equal('bbbbbbbbb')
+  })
+})