@putout/plugin-regexp [![NPM version][NPMIMGURL]][NPMURL]

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[NPMURL]: https://npmjs.org/package/@putout/plugin-regexp "npm"

> Regular expressions are patterns used to match character combinations in strings.
>
> (c) MDN

🐊Putout plugin helps with Regular Expressions.

Install

``
npm i @putout/plugin-regexp -D
`

Rules

- ✅ apply-character-class;
- ✅ apply-ends-with;
- ✅ apply-global-regexp-to-replace-al;
- ✅ apply-literal-notation;
- ✅ apply-starts-with;
- ✅ convert-replace-to-replace-all;
- ✅ convert-to-string;
- ✅ optimize;
- ✅ remove-useless-group;
- ✅ remove-useless-regexp;
- ✅ remove-useless-escape;
- ✅ remove-duplicates-from-character-class;

Config

`json
{
"rules": {
"regexp/apply-character-class": "on",
"regexp/apply-global-regexp-to-replace-all": "on",
"regexp/apply-literal-notation": "on",
"regexp/apply-starts-with": "on",
"regexp/apply-ends-with": "on",
"regexp/optimize": "on",
"regexp/convert-to-string": "on",
"regexp/convert-replace-to-replace-all": "on",
"regexp/remove-useless-group": "on",
"regexp/remove-useless-escape": "on",
"regexp/remove-useless-regexp": "on",
"regexp/remove-duplicates-from-character-class": "on"
}
}
`

optimize

$3

`js
const a = /(ab|ab)/;
`

$3

`js
const a = /(ab)/;
`

apply-character-class

Checkout in:

- 🐊Putout Editor.
- AST Explorer.

$3

`js
/\)|\(/g;
`

$3

`js
/[)(]/g;
`

apply-global-regexp-to-replace-all

> Uncaught TypeError: String.prototype.replaceAll called with a non-global RegExp argument
>
> (c) MDN

Checkout in 🐊Putout Editor.

$3

`js
's'.replaceAll(/hello/, 's');
'abc'.matchAll(/./);
`

$3

`js
's'.replaceAll(/hello/g, 's');
'abc'.matchAll(/./g);
`

apply-literal-notation

$3

`js
const a = new RegExp('hello', 'i');
`

$3

`js
const a = /hello/i;
`

apply-starts-with

> The startsWith() method determines whether a string begins with the characters of a specified string, returning true or false as appropriate.
>
> (c) MDN

RegExp is overkill for such a simple task as determining that string located at the beginning. Check it out in 🐊 Putout Editor.

$3

`js
/^hello/.test(a);
`

$3

`js
a.startsWith('hello');
`

$3

Linter | Rule | Fix
--------|-------|------------|
🐊 Putout| regexp/apply-starts-with| ✅
🦕 TypeScript ESLint | prefer-string-starts-ends-with | ✅

apply-ends-with

> The startsWith() method determines whether a string ends with the characters of a specified string, returning true or false as appropriate.
>
> (c) MDN

RegExp is overkill for such a simple task as determining that string located at the end.

$3

`js
/hello$/.test(a);
`

$3

`js
a.endsWith('hello');
`

$3

Linter | Rule | Fix
--------|-------|------------|
🐊 Putout| regexp/apply-ends-with| ✅
🦕 TypeScript ESLint | prefer-string-starts-ends-with | ✅

convert-to-string

$3

`js
'hello'.replace(/hello/, 'world');
`

$3

`js
'hello'.replace('hello', 'world');
`

convert-replace-to-replace-all

Simplify code according to string-replace-all.

$3

`js
'hello'.replace(/hello/g, 'world');
`

$3

`js
'hello'.replaceAll('hello', 'world');
`

remove-useless-group

$3

`js
/(hello)/.test(str);
`

$3

`js
/hello/.test(str);
`

remove-useless-escape

Checkout in 🐊Putout Editor.

$3

`js
const cleanText = code.replaceAll(/[,;\(\)]/g, '');
`

$3

`js
const cleanText = code.replaceAll(/[,;()]/g, '');
`

$3

Linter | Rule | Fix
--------|-------|------------|
🐊 Putout| regexp/remove-useless-escape| ✅
⏣ ESLint | no-useless-escape | ❌

remove-useless-regexp

$3

`js
const a = /^\.hello$/.test(str);
`

$3

`js
const a = str === '.hello';
`

remove-duplicates-from-character-class

Checkout in AST Explorer.

$3

`js
/[aaabb]/.test(str);
`

$3

`js
/[ab]/.test(str);
``

License

MIT