no-array-for-each: Improve parameter reassign detection (#1823)

sindresorhus · May 25, 2022 · 56df468 · 56df468
1 parent 330d1dd
commit 56df468
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Showing 4 changed files with 836 additions and 9 deletions.
diff --git a/rules/no-array-for-each.js b/rules/no-array-for-each.js
@@ -317,18 +317,34 @@ function isFunctionParametersSafeToFix(callbackFunction, {context, scope, callEx
 	return true;
 }
 
+// TODO[@fisker]: Improve `./utils/is-left-hand-side.js` with similar logic
+function isAssignmentLeftHandSide(node) {
+	const {parent} = node;
+
+	switch (parent.type) {
+		case 'AssignmentExpression':
+			return parent.left === node;
+		case 'UpdateExpression':
+			return parent.argument === node;
+		case 'Property':
+			return parent.value === node && isAssignmentLeftHandSide(parent);
+		case 'AssignmentPattern':
+			return parent.left === node && isAssignmentLeftHandSide(parent);
+		case 'ArrayPattern':
+			return parent.elements.includes(node) && isAssignmentLeftHandSide(parent);
+		case 'ObjectPattern':
+			return parent.properties.includes(node) && isAssignmentLeftHandSide(parent);
+		default:
+			return false;
+	}
+}
+
 function isFunctionParameterVariableReassigned(callbackFunction, context) {
 	return context.getDeclaredVariables(callbackFunction)
 		.filter(variable => variable.defs[0].type === 'Parameter')
-		.some(variable => {
-			const {references} = variable;
-			return references.some(reference => {
-				const node = reference.identifier;
-				const {parent} = node;
-				return parent.type === 'UpdateExpression'
-					|| (parent.type === 'AssignmentExpression' && parent.left === node);
-			});
-		});
+		.some(variable =>
+			variable.references.some(reference => isAssignmentLeftHandSide(reference.identifier)),
+		);
 }
 
 function isFixable(callExpression, {scope, functionInfo, allIdentifiers, context}) {

diff --git a/test/no-array-for-each.mjs b/test/no-array-for-each.mjs
@@ -441,6 +441,67 @@ test.snapshot({
 		// Arrow function body
 		'array.forEach((arrayInArray) => arrayInArray.forEach(element => bar(element)));',
 		'array.forEach((arrayInArray) => arrayInArray?.forEach(element => bar(element)));',
+
+		// Destructuring assign
+		...[
+			'({element} = bar)',
+			'({element: a} = bar)',
+			'({a: element} = bar)',
+			'({[element]: a} = bar)',
+			'({[a]: element} = bar)',
+			'({element = a} = bar)',
+			'({a = element} = bar)',
+			'[element] = bar',
+			'[element = a] = bar',
+			'[a = element] = bar',
+			'({deep: {element}} = bar)',
+			'({deep: {element: a}} = bar)',
+			'({deep: {a: element}} = bar)',
+			'({deep: {[element]: a}} = bar)',
+			'({deep: {[a]: element}} = bar)',
+			'({deep: {element = a}} = bar)',
+			'({deep: {a = element}} = bar)',
+			'({deep: [element]} = bar)',
+			'({deep: [element = a]} = bar)',
+			'({deep: [a = element]} = bar)',
+			'[{element}] = bar',
+			'[{element: a}] = bar',
+			'[{a: element}] = bar',
+			'[{[element]: a}] = bar',
+			'[{[a]: element}] = bar',
+			'[{element = a}] = bar',
+			'[{a = element}] = bar',
+			'[[element]] = bar',
+			'[[element = a]] = bar',
+			'[[a = element]] = bar',
+		].map(code => outdent`
+			foo.forEach(element => {
+				${code};
+			});
+		`),
+		outdent`
+			foo.forEach(element => {
+				[
+					bar = ((element) => {
+						[element] = array;
+					})(element)
+				] = baz;
+			});
+		`,
+		outdent`
+			foo.forEach(element => {
+				[
+					bar = ((element = array) => element)(element)
+				] = baz;
+			});
+		`,
+		outdent`
+			foo.forEach(element => {
+				[
+					bar = (([element] = array) => element)(element)
+				] = baz;
+			});
+		`,
 	],
 });