prefer-date-now: Use simple selectors (#2110)

Author: fisker

rules/prefer-date-now.js

@@ -1,10 +1,9 @@
 'use strict';
 const {
-	matches,
-	methodCallSelector,
-	newExpressionSelector,
-	callExpressionSelector,
-} = require('./selectors/index.js');
+	isMethodCall,
+	isCallExpression,
+	isNewExpression,
+} = require('./ast/index.js');
 const {fixSpaceAroundKeyword} = require('./fix/index.js');
 
 const MESSAGE_ID_DEFAULT = 'prefer-date';
@@ -16,42 +15,7 @@ const messages = {
 	[MESSAGE_ID_NUMBER]: 'Prefer `Date.now()` over `Number(new Date())`.',
 };
 
-const createNewDateSelector = path => newExpressionSelector({path, name: 'Date', argumentsLength: 0});
-const operatorsSelector = (...operators) => matches(operators.map(operator => `[operator="${operator}"]`));
-// `new Date()`
-const newDateSelector = createNewDateSelector();
-// `new Date().{getTime,valueOf}()`
-const methodsSelector = [
-	methodCallSelector({
-		methods: ['getTime', 'valueOf'],
-		argumentsLength: 0,
-	}),
-	createNewDateSelector('callee.object'),
-].join('');
-// `{Number,BigInt}(new Date())`
-const builtinObjectSelector = [
-	callExpressionSelector({names: ['Number', 'BigInt'], argumentsLength: 1}),
-	createNewDateSelector('arguments.0'),
-].join('');
-// https://github.com/estree/estree/blob/master/es5.md#unaryoperator
-const unaryExpressionsSelector = [
-	'UnaryExpression',
-	operatorsSelector('+', '-'),
-	createNewDateSelector('argument'),
-].join('');
-const assignmentExpressionSelector = [
-	'AssignmentExpression',
-	operatorsSelector('-=', '*=', '/=', '%=', '**='),
-	'>',
-	`${newDateSelector}.right`,
-].join('');
-const binaryExpressionSelector = [
-	'BinaryExpression',
-	operatorsSelector('-', '*', '/', '%', '**'),
-	// Both `left` and `right` properties
-	'>',
-	newDateSelector,
-].join('');
+const isNewDate = node => isNewExpression(node, {name: 'Date', argumentsLength: 0});
 
 const getProblem = (node, problem, sourceCode) => ({
 	node,
@@ -68,36 +32,92 @@ const getProblem = (node, problem, sourceCode) => ({
 
 /** @param {import('eslint').Rule.RuleContext} context */
 const create = context => ({
-	[methodsSelector](node) {
-		const method = node.callee.property;
-		return getProblem(node, {
-			node: method,
-			messageId: MESSAGE_ID_METHOD,
-			data: {method: method.name},
-		});
-	},
-	[builtinObjectSelector](node) {
-		const {name} = node.callee;
-		if (name === 'Number') {
-			return getProblem(node, {
-				messageId: MESSAGE_ID_NUMBER,
+	CallExpression(callExpression) {
+		// `new Date().{getTime,valueOf}()`
+		if (
+			isMethodCall(callExpression, {
+				methods: ['getTime', 'valueOf'],
+				argumentsLength: 0,
+				optionalCall: false,
+				optionalMember: false,
+			})
+			&& isNewDate(callExpression.callee.object)
+		) {
+			const method = callExpression.callee.property;
+			return getProblem(callExpression, {
+				node: method,
+				messageId: MESSAGE_ID_METHOD,
+				data: {method: method.name},
 			});
 		}
 
-		return getProblem(node.arguments[0]);
+		// `{Number,BigInt}(new Date())`
+		if (
+			isCallExpression(callExpression, {
+				names: ['Number', 'BigInt'],
+				argumentsLength: 1,
+				optional: false,
+			})
+			&& isNewDate(callExpression.arguments[0])
+		) {
+			const {name} = callExpression.callee;
+			if (name === 'Number') {
+				return getProblem(callExpression, {
+					messageId: MESSAGE_ID_NUMBER,
+				});
+			}
+
+			return getProblem(callExpression.arguments[0]);
+		}
 	},
-	[unaryExpressionsSelector](node) {
-		return getProblem(
-			node.operator === '-' ? node.argument : node,
-			{},
-			context.sourceCode,
-		);
+	UnaryExpression(unaryExpression) {
+		// https://github.com/estree/estree/blob/master/es5.md#unaryoperator
+		if (
+			unaryExpression.operator !== '+'
+			&& unaryExpression.operator !== '-'
+		) {
+			return;
+		}
+
+		if (isNewDate(unaryExpression.argument)) {
+			return getProblem(
+				unaryExpression.operator === '-' ? unaryExpression.argument : unaryExpression,
+				{},
+				context.sourceCode,
+			);
+		}
 	},
-	[assignmentExpressionSelector](node) {
-		return getProblem(node);
+	AssignmentExpression(assignmentExpression) {
+		if (
+			assignmentExpression.operator !== '-='
+			&& assignmentExpression.operator !== '*='
+			&& assignmentExpression.operator !== '/='
+			&& assignmentExpression.operator !== '%='
+			&& assignmentExpression.operator !== '**='
+		) {
+			return;
+		}
+
+		if (isNewDate(assignmentExpression.right)) {
+			return getProblem(assignmentExpression.right);
+		}
 	},
-	[binaryExpressionSelector](node) {
-		return getProblem(node);
+	* BinaryExpression(binaryExpression) {
+		if (
+			binaryExpression.operator !== '-'
+			&& binaryExpression.operator !== '*'
+			&& binaryExpression.operator !== '/'
+			&& binaryExpression.operator !== '%'
+			&& binaryExpression.operator !== '**'
+		) {
+			return;
+		}
+
+		for (const node of [binaryExpression.left, binaryExpression.right]) {
+			if (isNewDate(node)) {
+				yield getProblem(node);
+			}
+		}
 	},
 });