Add prefer-array-some rule (#887)

docs/rules/prefer-array-some.md

@@ -0,0 +1,27 @@
+# Prefer `.some(…)` over `.find(…)`.
+
+Prefer using [`Array#some`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/some) over [`Array#find`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/find) when ensuring at least one element in the array passes a given check.
+
+## Fail
+
+```js
+if (array.find(element => element === '🦄')) {
+	// …
+}
+```
+
+```js
+const foo = array.find(element => element === '🦄') ? bar : baz;
+```
+
+## Pass
+
+```js
+if (array.some(element => element === '🦄')) {
+	// …
+}
+```
+
+```js
+const foo = array.find(element => element === '🦄') || bar;
+```

index.js

@@ -65,6 +65,7 @@ module.exports = {
 				'unicorn/numeric-separators-style': 'off',
 				'unicorn/prefer-add-event-listener': 'error',
 				'unicorn/prefer-array-find': 'error',
+				'unicorn/prefer-array-some': 'error',
 				'unicorn/prefer-dataset': 'error',
 				'unicorn/prefer-date-now': 'error',
 				'unicorn/prefer-default-parameters': 'error',

readme.md

@@ -70,6 +70,7 @@ Configure it in `package.json`.
 			"unicorn/numeric-separators-style": "off",
 			"unicorn/prefer-add-event-listener": "error",
 			"unicorn/prefer-array-find": "error",
+			"unicorn/prefer-array-some": "error",
 			"unicorn/prefer-dataset": "error",
 			"unicorn/prefer-date-now": "error",
 			"unicorn/prefer-default-parameters": "error",
@@ -140,6 +141,7 @@ Configure it in `package.json`.
 - [numeric-separators-style](docs/rules/numeric-separators-style.md) - Enforce the style of numeric separators by correctly grouping digits. *(fixable)*
 - [prefer-add-event-listener](docs/rules/prefer-add-event-listener.md) - Prefer `.addEventListener()` and `.removeEventListener()` over `on`-functions. *(partly fixable)*
 - [prefer-array-find](docs/rules/prefer-array-find.md) - Prefer `.find(…)` over the first element from `.filter(…)`. *(partly fixable)*
+- [prefer-array-some](docs/rules/prefer-array-some.md) - Prefer `.some(…)` over `.find(…)`.
 - [prefer-dataset](docs/rules/prefer-dataset.md) - Prefer using `.dataset` on DOM elements over `.setAttribute(…)`. *(fixable)*
 - [prefer-date-now](docs/rules/prefer-date-now.md) - Prefer `Date.now()` to get the number of milliseconds since the Unix Epoch. *(fixable)*
 - [prefer-default-parameters](docs/rules/prefer-default-parameters.md) - Prefer default parameters over reassignment. *(fixable)*

rules/explicit-length-check.js

@@ -2,6 +2,7 @@
 const {isParenthesized} = require('eslint-utils');
 const getDocumentationUrl = require('./utils/get-documentation-url');
 const isLiteralValue = require('./utils/is-literal-value');
+const {isBooleanNode, getBooleanAncestor} = require('./utils/boolean');
 
 const TYPE_NON_ZERO = 'non-zero';
 const TYPE_ZERO = 'zero';
@@ -12,23 +13,6 @@ const messages = {
 	[MESSAGE_ID_SUGGESTION]: 'Replace `.length` with `.length {{code}}`.'
 };
 
-const isLogicNot = node =>
-	node &&
-	node.type === 'UnaryExpression' &&
-	node.operator === '!';
-const isLogicNotArgument = node =>
-	isLogicNot(node.parent) &&
-	node.parent.argument === node;
-const isBooleanCall = node =>
-	node &&
-	node.type === 'CallExpression' &&
-	node.callee &&
-	node.callee.type === 'Identifier' &&
-	node.callee.name === 'Boolean' &&
-	node.arguments.length === 1;
-const isBooleanCallArgument = node =>
-	isBooleanCall(node.parent) &&
-	node.parent.arguments[0] === node;
 const isCompareRight = (node, operator, value) =>
 	node.type === 'BinaryExpression' &&
 	node.operator === operator &&
@@ -72,23 +56,6 @@ const lengthSelector = [
 	'[property.name="length"]'
 ].join('');
 
-function getBooleanAncestor(node) {
-	let isNegative = false;
-	// eslint-disable-next-line no-constant-condition
-	while (true) {
-		if (isLogicNotArgument(node)) {
-			isNegative = !isNegative;
-			node = node.parent;
-		} else if (isBooleanCallArgument(node)) {
-			node = node.parent;
-		} else {
-			break;
-		}
-	}
-
-	return {node, isNegative};
-}
-
 function getLengthCheckNode(node) {
 	node = node.parent;
 
@@ -135,37 +102,6 @@ function getLengthCheckNode(node) {
 	return {};
 }
 
-function isBooleanNode(node) {
-	if (
-		isLogicNot(node) ||
-		isLogicNotArgument(node) ||
-		isBooleanCall(node) ||
-		isBooleanCallArgument(node)
-	) {
-		return true;
-	}
-
-	const {parent} = node;
-	if (
-		(
-			parent.type === 'IfStatement' ||
-			parent.type === 'ConditionalExpression' ||
-			parent.type === 'WhileStatement' ||
-			parent.type === 'DoWhileStatement' ||
-			parent.type === 'ForStatement'
-		) &&
-		parent.test === node
-	) {
-		return true;
-	}
-
-	if (parent.type === 'LogicalExpression') {
-		return isBooleanNode(parent);
-	}
-
-	return false;
-}
-
 function create(context) {
 	const options = {
 		'non-zero': 'greater-than',

rules/prefer-array-some.js

@@ -0,0 +1,48 @@
+'use strict';
+const getDocumentationUrl = require('./utils/get-documentation-url');
+const methodSelector = require('./utils/method-selector');
+const {isBooleanNode} = require('./utils/boolean');
+
+const MESSAGE_ID_ERROR = 'error';
+const MESSAGE_ID_SUGGESTION = 'suggestion';
+const messages = {
+	[MESSAGE_ID_ERROR]: 'Prefer `.some(…)` over `.find(…)`.',
+	[MESSAGE_ID_SUGGESTION]: 'Replace `.find(…)` with `.some(…)`.'
+};
+
+const arrayFindCallSelector = methodSelector({
+	name: 'find',
+	min: 1,
+	max: 2
+});
+
+const create = context => {
+	return {
+		[arrayFindCallSelector](node) {
+			if (isBooleanNode(node)) {
+				node = node.callee.property;
+				context.report({
+					node,
+					messageId: MESSAGE_ID_ERROR,
+					suggest: [
+						{
+							messageId: MESSAGE_ID_SUGGESTION,
+							fix: fixer => fixer.replaceText(node, 'some')
+						}
+					]
+				});
+			}
+		}
+	};
+};
+
+module.exports = {
+	create,
+	meta: {
+		type: 'suggestion',
+		docs: {
+			url: getDocumentationUrl(__filename)
+		},
+		messages
+	}
+};

rules/prefer-event-key.js

@@ -171,7 +171,7 @@ const create = context => {
 
 			if (
 				references &&
-				references.find(reference => isPropertyOf(node, reference.identifier))
+				references.some(reference => isPropertyOf(node, reference.identifier))
 			) {
 				report(node);
 			}
@@ -201,7 +201,7 @@ const create = context => {
 			// Make sure initObject is a reference of eventVariable
 			if (
 				references &&
-				references.find(reference => reference.identifier === initObject)
+				references.some(reference => reference.identifier === initObject)
 			) {
 				report(node.value);
 				return;

rules/utils/boolean.js

@@ -0,0 +1,83 @@
+'use strict';
+
+const isLogicNot = node =>
+	node &&
+	node.type === 'UnaryExpression' &&
+	node.operator === '!';
+const isLogicNotArgument = node =>
+	isLogicNot(node.parent) &&
+	node.parent.argument === node;
+const isBooleanCallArgument = node =>
+	isBooleanCall(node.parent) &&
+	node.parent.arguments[0] === node;
+const isBooleanCall = node =>
+	node &&
+	node.type === 'CallExpression' &&
+	node.callee &&
+	node.callee.type === 'Identifier' &&
+	node.callee.name === 'Boolean' &&
+	node.arguments.length === 1;
+
+/**
+Check if the value of node is a `boolean`.
+
+@param {Node} node
+@returns {boolean}
+*/
+function isBooleanNode(node) {
+	if (
+		isLogicNot(node) ||
+		isLogicNotArgument(node) ||
+		isBooleanCall(node) ||
+		isBooleanCallArgument(node)
+	) {
+		return true;
+	}
+
+	const {parent} = node;
+	if (
+		(
+			parent.type === 'IfStatement' ||
+			parent.type === 'ConditionalExpression' ||
+			parent.type === 'WhileStatement' ||
+			parent.type === 'DoWhileStatement' ||
+			parent.type === 'ForStatement'
+		) &&
+		parent.test === node
+	) {
+		return true;
+	}
+
+	if (parent.type === 'LogicalExpression') {
+		return isBooleanNode(parent);
+	}
+
+	return false;
+}
+
+/**
+Get the boolean type-casting ancestor.
+
+@typedef {{ node: Node, isNegative: boolean }} Result
+
+@param {Node} node
+@returns {Result}
+*/
+function getBooleanAncestor(node) {
+	let isNegative = false;
+	// eslint-disable-next-line no-constant-condition
+	while (true) {
+		if (isLogicNotArgument(node)) {
+			isNegative = !isNegative;
+			node = node.parent;
+		} else if (isBooleanCallArgument(node)) {
+			node = node.parent;
+		} else {
+			break;
+		}
+	}
+
+	return {node, isNegative};
+}
+
+module.exports = {isBooleanNode, getBooleanAncestor};