/String.prototype.matchAll

Spec-compliant polyfill for String.prototype.matchAll, in ES2020

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ES2020 spec-compliant shim for String.prototype.matchAll. Invoke its "shim" method to shim String.prototype.matchAll if it is unavailable or noncompliant.

This package implements the es-shim API interface. It works in an ES3-supported environment, and complies with the spec.

Most common usage:

const assert = require('assert');
const matchAll = require('string.prototype.matchall');

const str = 'aabc';
const nonRegexStr = 'ab';
const globalRegex = /[ac]/g;
const nonGlobalRegex = /[bc]/i;

// non-regex arguments are coerced into a global regex
assert.deepEqual(
	[...matchAll(str, nonRegexStr)],
	[...matchAll(str, new RegExp(nonRegexStr, 'g'))]
);

assert.deepEqual([...matchAll(str, globalRegex)], [
	Object.assign(['a'], { index: 0, input: str, groups: undefined }),
	Object.assign(['a'], { index: 1, input: str, groups: undefined }),
	Object.assign(['c'], { index: 3, input: str, groups: undefined }),
]);

assert.throws(() => matchAll(str, nonGlobalRegex)); // non-global regexes throw

matchAll.shim(); // will be a no-op if not needed

// non-regex arguments are coerced into a global regex
assert.deepEqual(
	[...str.matchAll(nonRegexStr)],
	[...str.matchAll(new RegExp(nonRegexStr, 'g'))]
);

assert.deepEqual([...str.matchAll(globalRegex)], [
	Object.assign(['a'], { index: 0, input: str, groups: undefined }),
	Object.assign(['a'], { index: 1, input: str, groups: undefined }),
	Object.assign(['c'], { index: 3, input: str, groups: undefined }),
]);

assert.throws(() => matchAll(str, nonGlobalRegex)); // non-global regexes throw

Tests

Simply clone the repo, npm install, and run npm test