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Add prefer-replace-all rule #488

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21 changes: 21 additions & 0 deletions docs/rules/prefer-replace-all.md
@@ -0,0 +1,21 @@
# Prefer `String#replaceAll()` over regex searches with the global flag

The [`String#replaceAll()`](https://github.com/tc39/proposal-string-replaceall) method is both faster and safer as you don't have to escape the regex if the string is not a literal.

This rule is fixable.

## Fail

```js
string.replace(/This has no special regex symbols/g, '');
string.replace(/\(It also checks for escaped regex symbols\)/g, '');
```

## Pass

```js
string.replace(/Non-literal characters .*/g, '');
string.replace(/Extra flags/gi, '');
string.replace('Not a regex expression', '')
string.replaceAll('Literal characters only', '');
```
1 change: 1 addition & 0 deletions index.js
Expand Up @@ -54,6 +54,7 @@ module.exports = {
'unicorn/prefer-node-remove': 'error',
'unicorn/prefer-query-selector': 'error',
'unicorn/prefer-reflect-apply': 'error',
'unicorn/prefer-replace-all': 'off',
'unicorn/prefer-spread': 'error',
'unicorn/prefer-starts-ends-with': 'error',
'unicorn/prefer-string-slice': 'error',
Expand Down
2 changes: 2 additions & 0 deletions readme.md
Expand Up @@ -72,6 +72,7 @@ Configure it in `package.json`.
"unicorn/prefer-node-remove": "error",
"unicorn/prefer-query-selector": "error",
"unicorn/prefer-reflect-apply": "error",
"unicorn/prefer-replace-all": "off",
"unicorn/prefer-spread": "error",
"unicorn/prefer-starts-ends-with": "error",
"unicorn/prefer-string-slice": "error",
Expand Down Expand Up @@ -125,6 +126,7 @@ Configure it in `package.json`.
- [prefer-node-remove](docs/rules/prefer-node-remove.md) - Prefer `node.remove()` over `parentNode.removeChild(node)` and `parentElement.removeChild(node)`. *(fixable)*
- [prefer-query-selector](docs/rules/prefer-query-selector.md) - Prefer `.querySelector()` over `.getElementById()`, `.querySelectorAll()` over `.getElementsByClassName()` and `.getElementsByTagName()`. *(partly fixable)*
- [prefer-reflect-apply](docs/rules/prefer-reflect-apply.md) - Prefer `Reflect.apply()` over `Function#apply()`. *(fixable)*
- [prefer-replace-all](docs/rules/prefer-replace-all.md) - Prefer `String#replaceAll()` over regex searches with the global flag. *(fixable)*
- [prefer-spread](docs/rules/prefer-spread.md) - Prefer the spread operator over `Array.from()`. *(fixable)*
- [prefer-starts-ends-with](docs/rules/prefer-starts-ends-with.md) - Prefer `String#startsWith()` & `String#endsWith()` over more complex alternatives.
- [prefer-string-slice](docs/rules/prefer-string-slice.md) - Prefer `String#slice()` over `String#substr()` and `String#substring()`. *(partly fixable)*
Expand Down
67 changes: 67 additions & 0 deletions rules/prefer-replace-all.js
@@ -0,0 +1,67 @@
'use strict';
const getDocumentationUrl = require('./utils/get-documentation-url');
const quoteString = require('./utils/quote-string');

function isRegexWithGlobalFlag(node) {
const {type, regex} = node;
return type === 'Literal' && regex && regex.flags === 'g';
}

function isLiteralCharactersOnly(node) {
const searchPattern = node.regex.pattern;
return !/[$()*+.?[\\\]^{}]/.test(searchPattern.replace(/\\[$()*+.?[\\\]^{}]/g, ''));
}

function removeEscapeCharacters(regexString) {
let fixedString = regexString;
let index = 0;
do {
index = fixedString.indexOf('\\', index);

if (index >= 0) {
fixedString = fixedString.slice(0, index) + fixedString.slice(index + 1);
index++;
}
} while (index >= 0);

return fixedString;
}

const create = context => {
return {
'CallExpression[callee.property.name="replace"]': node => {
const {arguments: arguments_} = node;

if (arguments_.length !== 2) {
return;
}

const [search] = arguments_;

if (!isRegexWithGlobalFlag(search) || !isLiteralCharactersOnly(search)) {
return;
}

context.report({
node,
message: 'Prefer `String#replaceAll()` over `String#replace()`.',
fix: fixer =>
[
fixer.insertTextAfter(node.callee, 'All'),
fixer.replaceText(search, quoteString(removeEscapeCharacters(search.regex.pattern)))
]
});
}
};
};

module.exports = {
create,
meta: {
type: 'suggestion',
docs: {
url: getDocumentationUrl(__filename)
},
fixable: 'code'
}
};
89 changes: 89 additions & 0 deletions test/prefer-replace-all.js
@@ -0,0 +1,89 @@
import test from 'ava';
import avaRuleTester from 'eslint-ava-rule-tester';
const rule = require('../rules/prefer-replace-all');

const ruleTester = avaRuleTester(test, {
env: {
es6: true
}
});

const error = {
ruleId: 'prefer-replace-all',
message: 'Prefer `String#replaceAll()` over `String#replace()`.'
};

ruleTester.run('prefer-replace-all', rule, {
valid: [
// No global flag
'foo.replace(/a/, bar)',
// Special characters
'foo.replace(/[a]/g, bar)',
'foo.replace(/a?/g, bar)',
'foo.replace(/.*/g, bar)',
'foo.replace(/\\W/g, bar)',
// Extra flag
'foo.replace(/a/gi, bar)',
// Not regex literal
'foo.replace(\'string\', bar)',
// Not 2 arguments
'foo.replace(/a/g)',
'foo.replace(/\\\\./g)',
// New
'new foo.replace(/a/g, bar)',
// Function call
'replace(/a/g, bar)',
// Not call
'foo.replace',
// Not replace
'foo.methodNotReplace(/a/g, bar);',
// `replace` is not Identifier
'foo[\'replace\'](/a/g, bar)'
],
invalid: [
{
code: 'foo.replace(/a/g, bar)',
output: 'foo.replaceAll(\'a\', bar)',
errors: [error]
},
// Comments
{
code: `
foo/* comment 1 */
.replace/* comment 2 */(
/* comment 3 */
/a/g // comment 4
,
bar
)
`,
output: `
foo/* comment 1 */
.replaceAll/* comment 2 */(
/* comment 3 */
'a' // comment 4
,
bar
)
`,
errors: [error]
},
// Quotes
{
code: 'foo.replace(/"\'/g, \'\\\'\')',
output: 'foo.replaceAll(\'"\\\'\', \'\\\'\')',
errors: [error]
},
// Escaped symbols
{
code: 'foo.replace(/\\./g, bar)',
output: 'foo.replaceAll(\'.\', bar)',
errors: [error]
},
{
code: 'foo.replace(/\\\\\\./g, bar)',
output: 'foo.replaceAll(\'\\.\', bar)',
errors: [error]
}
]
});