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Add prefer-modern-math-apis rule (#1780)
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‎configs/recommended.js

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@@ -84,6 +84,7 @@ module.exports = {
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'unicorn/prefer-keyboard-event-key': 'error',
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'unicorn/prefer-math-trunc': 'error',
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'unicorn/prefer-modern-dom-apis': 'error',
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'unicorn/prefer-modern-math-apis': 'error',
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'unicorn/prefer-module': 'error',
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'unicorn/prefer-negative-index': 'error',
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'unicorn/prefer-node-protocol': 'error',

‎docs/rules/prefer-modern-math-apis.md

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# Prefer modern `Math` APIs over legacy patterns
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<!-- Do not manually modify RULE_NOTICE part. Run: `npm run generate-rule-notices` -->
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<!-- RULE_NOTICE -->
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✅ *This rule is part of the [recommended](https://github.com/sindresorhus/eslint-plugin-unicorn#recommended-config) config.*
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🔧 *This rule is [auto-fixable](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems).*
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<!-- /RULE_NOTICE -->
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Math additions in ES2015:
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- [Math.sign()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/sign)
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- [Math.trunc()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/trunc)
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- [Math.cbrt()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/cbrt)
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- [Math.expm1()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/expm1)
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- [Math.log1p()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log1p)
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- [Math.log10()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log10)
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- [Math.log2()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/log2)
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- [Math.sinh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/sinh)
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- [Math.cosh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/cosh)
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- [Math.tanh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/tanh)
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- [Math.asinh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/asinh)
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- [Math.acosh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/acosh)
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- [Math.atanh()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/atanh)
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- [Math.hypot()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/hypot)
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- [Math.clz32()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/clz32)
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- [Math.imul()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/imul)
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- [Math.fround()](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Math/fround)
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Currently, we only check a few known cases, but we are open to add more patterns.
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If you find a suitable case for this rule, please [open an issue](https://github.com/sindresorhus/eslint-plugin-unicorn/issues/new?title=%20%60prefer-modern-math-apis%60%20%20change%20request&labels=evaluating).
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## Prefer `Math.log10(x)` over
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```js
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Math.log(x) * Math.LOG10E
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```
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```js
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Math.LOG10E * Math.log(x)
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```
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```js
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Math.log(x) / Math.LN10
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```
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## Prefer `Math.log2(x)` over
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```js
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Math.log(x) * Math.LOG2E
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```
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```js
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Math.LOG2E * Math.log(x)
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```
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```js
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Math.log(x) / Math.LN2
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```
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## Separate rule for `Math.trunc()`
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See [`unicorn/prefer-math-trunc`](./prefer-math-trunc.md) rule.

‎readme.md

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@@ -124,6 +124,7 @@ Each rule has emojis denoting:
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| [prefer-keyboard-event-key](docs/rules/prefer-keyboard-event-key.md) | Prefer `KeyboardEvent#key` over `KeyboardEvent#keyCode`. | ✅ | 🔧 | |
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| [prefer-math-trunc](docs/rules/prefer-math-trunc.md) | Enforce the use of `Math.trunc` instead of bitwise operators. | ✅ | 🔧 | 💡 |
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| [prefer-modern-dom-apis](docs/rules/prefer-modern-dom-apis.md) | Prefer `.before()` over `.insertBefore()`, `.replaceWith()` over `.replaceChild()`, prefer one of `.before()`, `.after()`, `.append()` or `.prepend()` over `insertAdjacentText()` and `insertAdjacentElement()`. | ✅ | 🔧 | |
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| [prefer-modern-math-apis](docs/rules/prefer-modern-math-apis.md) | Prefer modern `Math` APIs over legacy patterns. | ✅ | 🔧 | |
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| [prefer-module](docs/rules/prefer-module.md) | Prefer JavaScript modules (ESM) over CommonJS. | ✅ | 🔧 | 💡 |
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| [prefer-negative-index](docs/rules/prefer-negative-index.md) | Prefer negative index over `.length - index` for `{String,Array,TypedArray}#slice()`, `Array#splice()` and `Array#at()`. | ✅ | 🔧 | |
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| [prefer-node-protocol](docs/rules/prefer-node-protocol.md) | Prefer using the `node:` protocol when importing Node.js builtin modules. | ✅ | 🔧 | |

‎rules/prefer-modern-math-apis.js

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'use strict';
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const {getParenthesizedText} = require('./utils/parentheses.js');
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const MESSAGE_ID = 'prefer-modern-math-apis';
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const messages = {
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[MESSAGE_ID]: 'Prefer `{{replacement}}` over `{{description}}`.',
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};
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const isMathProperty = (node, property) =>
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node.type === 'MemberExpression'
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&& !node.optional
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&& !node.computed
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&& node.object.type === 'Identifier'
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&& node.object.name === 'Math'
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&& node.property.type === 'Identifier'
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&& node.property.name === property;
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const isMathMethodCall = (node, method) =>
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node.type === 'CallExpression'
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&& !node.optional
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&& isMathProperty(node.callee, method)
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&& node.arguments.length === 1
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&& node.arguments[0].type !== 'SpreadElement';
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// `Math.log(x) * Math.LOG10E` -> `Math.log10(x)`
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// `Math.LOG10E * Math.log(x)` -> `Math.log10(x)`
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// `Math.log(x) * Math.LOG2E` -> `Math.log2(x)`
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// `Math.LOG2E * Math.log(x)` -> `Math.log2(x)`
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function createLogCallTimesConstantCheck({constantName, replacementMethod}) {
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const replacement = `Math.${replacementMethod}(…)`;
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return function (node, context) {
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if (!(node.type === 'BinaryExpression' && node.operator === '*')) {
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return;
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}
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let mathLogCall;
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let description;
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if (isMathMethodCall(node.left, 'log') && isMathProperty(node.right, constantName)) {
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mathLogCall = node.left;
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description = `Math.log(…) * Math.${constantName}`;
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} else if (isMathMethodCall(node.right, 'log') && isMathProperty(node.left, constantName)) {
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mathLogCall = node.right;
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description = `Math.${constantName} * Math.log(…)`;
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}
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if (!mathLogCall) {
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return;
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}
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const [valueNode] = mathLogCall.arguments;
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return {
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node,
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messageId: MESSAGE_ID,
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data: {
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replacement,
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description,
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},
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fix: fixer => fixer.replaceText(node, `Math.${replacementMethod}(${getParenthesizedText(valueNode, context.getSourceCode())})`),
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};
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};
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}
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// `Math.log(x) / Math.LN10` -> `Math.log10(x)`
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// `Math.log(x) / Math.LN2` -> `Math.log2(x)`
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function createLogCallDivideConstantCheck({constantName, replacementMethod}) {
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const message = {
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messageId: MESSAGE_ID,
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data: {
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replacement: `Math.${replacementMethod}(…)`,
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description: `Math.log(…) / Math.${constantName}`,
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},
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};
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return function (node, context) {
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if (
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!(
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node.type === 'BinaryExpression'
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&& node.operator === '/'
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&& isMathMethodCall(node.left, 'log')
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&& isMathProperty(node.right, constantName)
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)
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) {
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return;
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}
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const [valueNode] = node.left.arguments;
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return {
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...message,
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node,
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fix: fixer => fixer.replaceText(node, `Math.${replacementMethod}(${getParenthesizedText(valueNode, context.getSourceCode())})`),
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};
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};
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}
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const checkFunctions = [
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createLogCallTimesConstantCheck({constantName: 'LOG10E', replacementMethod: 'log10'}),
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createLogCallTimesConstantCheck({constantName: 'LOG2E', replacementMethod: 'log2'}),
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createLogCallDivideConstantCheck({constantName: 'LN10', replacementMethod: 'log10'}),
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createLogCallDivideConstantCheck({constantName: 'LN2', replacementMethod: 'log2'}),
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];
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/** @param {import('eslint').Rule.RuleContext} context */
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const create = context => {
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const nodes = [];
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return {
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BinaryExpression(node) {
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nodes.push(node);
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},
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* 'Program:exit'() {
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for (const node of nodes) {
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for (const getProblem of checkFunctions) {
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const problem = getProblem(node, context);
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if (problem) {
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yield problem;
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}
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}
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}
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},
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};
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};
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/** @type {import('eslint').Rule.RuleModule} */
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module.exports = {
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create,
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meta: {
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type: 'suggestion',
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docs: {
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description: 'Prefer modern `Math` APIs over legacy patterns.',
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},
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fixable: 'code',
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messages,
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},
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};

‎test/package.mjs

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}
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const RULES_WITHOUT_PASS_FAIL_SECTIONS = new Set([
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'filename-case', // Doesn't show code samples since it's just focused on filenames.
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// Doesn't show code samples since it's just focused on filenames.
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'filename-case',
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// Intended to not use `pass`/`fail` section in this rule.
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'prefer-modern-math-apis',
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]);
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test('Every rule is defined in index file in alphabetical order', t => {

‎test/prefer-modern-math-apis.mjs

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import outdent from 'outdent';
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import {getTester} from './utils/test.mjs';
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const {test} = getTester(import.meta);
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// `Math.log10()` and `Math.log2()`
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const duplicateLog10Test = code => [
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code,
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// `Math.log2()` test
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code.replace(/Math\.LOG10E/g, 'Math.LOG2E').replace(/Math\.LN10/g, 'Math.LN2'),
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];
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test.snapshot({
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valid: [
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'Math.log(x) * Math.log(x)',
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'Math.LOG10E * Math.LOG10E',
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'Math.log(x) * Math[LOG10E]',
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'Math.log(x) * LOG10E',
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'Math[log](x) * Math.LOG10E',
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'foo.Math.log(x) * Math.LOG10E',
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'Math.log(x) * foo.Math.LOG10E',
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'Math.log(x) * Math.NOT_LOG10E',
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'Math.log(x) * Math?.LOG10E',
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'Math?.log(x) * Math.LOG10E',
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'log(x) * Math.LOG10E',
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'new Math.log(x) * Math.LOG10E',
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'Math.not_log(x) + Math.LOG10E',
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'Math.log(x)[Math.LOG10E]',
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'Math.log() * Math.LOG10E',
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'Math.log(x, extraArgument) * Math.LOG10E',
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'Math.log(...x) * Math.LOG10E',
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'Math.LN10 / Math.LN10',
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'Math.log(x) /Math[LN10]',
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'Math.log(x) / LN10',
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'Math[log](x) / Math.LN10',
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'foo.Math.log(x) / Math.LN10',
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'Math.log(x) / foo.Math.LN10',
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'Math.log(x) / Math.log(x)',
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'Math.log(x) / Math.NOT_LN10',
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'Math.log(x) / Math?.LN10',
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'Math?.log(x) / Math.LN10',
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'log(x) / Math.LN10',
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'new Math.log(x) / Math.LN10',
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'Math.not_log(x) + Math.LN10',
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'Math.log(x)[Math.LN10]',
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'Math.log() / Math.LN10',
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'Math.log(x, extraArgument) / Math.LN10',
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'Math.log(...x) / Math.LN10',
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].flatMap(code => duplicateLog10Test(code)),
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invalid: [
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'Math.log(x) * Math.LOG10E',
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'Math.LOG10E * Math.log(x)',
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'Math.log(x) / Math.LN10',
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'Math.log((( 0,x ))) * Math.LOG10E',
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'Math.LOG10E * Math.log((( 0,x )))',
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'Math.log((( 0,x ))) / Math.LN10',
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outdent`
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function foo(x) {
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return (
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Math.log(x)
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/ Math.LN10
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);
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}
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`,
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].flatMap(code => duplicateLog10Test(code)),
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});

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