Files
Webklar.com/node_modules/fast-equals/recipes/legacy-regexp-support.md
Basilosaurusrex f027651f9b main repo
2025-11-24 18:09:40 +01:00

25 lines
1.0 KiB
Markdown

# Legacy environment support for `RegExp` comparators
Starting in `4.x.x`, `RegExp.prototype.flags` is expected to be available in the environment. All modern browsers support this feature, however there may be situations where a legacy environmental support is required (example: IE11). If you need to support such an environment and polyfilling is not an option, creating a custom comparator that uses a more verbose comparison of all possible flags is a simple solution.
```ts
import { createCustomEqual, sameValueZeroEqual } from 'deep-Equals';
const areRegExpsEqual = (a: RegExp, b: RegExp) =>
a.source === b.source &&
a.global === b.global &&
a.ignoreCase === b.ignoreCase &&
a.multiline === b.multiline &&
a.unicode === b.unicode &&
a.sticky === b.sticky &&
a.lastIndex === b.lastIndex;
const deepEqual = createCustomEqual({
createCustomConfig: () => ({ areRegExpsEqual }),
});
const shallowEqual = createCustomEqual({
comparator: sameValueZero,
createCustomConfig: () => ({ areRegExpsEqual }),
});
```