prefer-optional-catch-binding: Support checking destructured errors (sindresorhus#1229)

Author: fisker

docs/rules/prefer-optional-catch-binding.md

@@ -7,7 +7,11 @@ This rule is fixable.
 ## Fail
 
 ```js
-try {} catch (usedError) {}
+try {} catch (notUsedError) {}
+```
+
+```js
+try {} catch ({message}) {}
 ```
 
 ## Pass

rules/prefer-optional-catch-binding.js

@@ -1,36 +1,35 @@
 'use strict';
 const getDocumentationUrl = require('./utils/get-documentation-url');
-const {findVariable, isOpeningParenToken, isClosingParenToken} = require('eslint-utils');
+const {isOpeningParenToken, isClosingParenToken} = require('eslint-utils');
 const assertToken = require('./utils/assert-token');
 
-const ERROR_MESSAGE_ID = 'error';
+const MESSAGE_ID_WITH_NAME = 'with-name';
+const MESSAGE_ID_WITHOUT_NAME = 'without-name';
 const messages = {
-	[ERROR_MESSAGE_ID]: 'Remove unused catch binding `{{name}}`.'
+	[MESSAGE_ID_WITH_NAME]: 'Remove unused catch binding `{{name}}`.',
+	[MESSAGE_ID_WITHOUT_NAME]: 'Remove unused catch binding.'
 };
 
 const selector = [
 	'CatchClause',
 	'>',
-	'Identifier.param'
+	'.param'
 ].join('');
 
 const create = context => {
-	const sourceCode = context.getSourceCode();
-
 	return {
 		[selector]: node => {
-			const scope = context.getScope();
-			const variable = findVariable(scope, node);
+			const variables = context.getDeclaredVariables(node.parent);
 
-			if (variable.references.length > 0) {
+			if (variables.some(variable => variable.references.length > 0)) {
 				return;
 			}
 
-			const {name, parent} = node;
+			const {type, name, parent} = node;
 
 			context.report({
 				node,
-				messageId: ERROR_MESSAGE_ID,
+				messageId: type === 'Identifier' ? MESSAGE_ID_WITH_NAME : MESSAGE_ID_WITHOUT_NAME,
 				data: {name},
 				* fix(fixer) {
 					const tokenBefore = context.getTokenBefore(node);
@@ -53,7 +52,7 @@ const create = context => {
 
 					const [, endOfClosingParenthesis] = tokenAfter.range;
 					const [startOfCatchClauseBody] = parent.body.range;
-					const text = sourceCode.text.slice(endOfClosingParenthesis, startOfCatchClauseBody);
+					const text = context.getSourceCode().text.slice(endOfClosingParenthesis, startOfCatchClauseBody);
 					const leadingSpacesLength = text.length - text.trimStart().length;
 					if (leadingSpacesLength !== 0) {
 						yield fixer.removeRange([endOfClosingParenthesis, endOfClosingParenthesis + leadingSpacesLength]);

test/prefer-optional-catch-binding.mjs

@@ -3,8 +3,7 @@ import {getTester} from './utils/test.mjs';
 
 const {test} = getTester(import.meta);
 
-const ERROR_MESSAGE_ID = 'error';
-const generateError = name => ({messageId: ERROR_MESSAGE_ID, data: {name}});
+const generateError = name => ({messageId: 'with-name', data: {name}});
 
 test({
 	valid: [
@@ -27,10 +26,7 @@ test({
 					}
 				}
 			}
-		`,
-		// We are not checking destructuring
-		'try {} catch({message}) {}',
-		'try {} catch({nonExistsProperty = thisWillExecute()}) {}'
+		`
 	],
 	invalid: [
 		{
@@ -173,3 +169,18 @@ test({
 		}
 	]
 });
+
+test.snapshot({
+	valid: [
+		'try {} catch ({message}) {alert(message)}',
+		'try {} catch ({cause: {message}}) {alert(message)}',
+		// Not sure about this case
+		'try {} catch({nonExistsProperty = thisWillExecute()}) {}'
+	],
+	invalid: [
+		'try {} catch ({}) {}',
+		'try {} catch ({message}) {}',
+		'try {} catch ({message: notUsedMessage}) {}',
+		'try {} catch ({cause: {message}}) {}'
+	]
+});

test/snapshots/prefer-optional-catch-binding.mjs.md

@@ -0,0 +1,69 @@
+# Snapshot report for `test/prefer-optional-catch-binding.mjs`
+
+The actual snapshot is saved in `prefer-optional-catch-binding.mjs.snap`.
+
+Generated by [AVA](https://avajs.dev).
+
+## Invalid #1
+      1 | try {} catch ({}) {}
+
+> Output
+
+    `␊
+      1 | try {} catch {}␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | try {} catch ({}) {}␊
+        |               ^^ Remove unused catch binding.␊
+    `
+
+## Invalid #2
+      1 | try {} catch ({message}) {}
+
+> Output
+
+    `␊
+      1 | try {} catch {}␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | try {} catch ({message}) {}␊
+        |               ^^^^^^^^^ Remove unused catch binding.␊
+    `
+
+## Invalid #3
+      1 | try {} catch ({message: notUsedMessage}) {}
+
+> Output
+
+    `␊
+      1 | try {} catch {}␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | try {} catch ({message: notUsedMessage}) {}␊
+        |               ^^^^^^^^^^^^^^^^^^^^^^^^^ Remove unused catch binding.␊
+    `
+
+## Invalid #4
+      1 | try {} catch ({cause: {message}}) {}
+
+> Output
+
+    `␊
+      1 | try {} catch {}␊
+    `
+
+> Error 1/1
+
+    `␊
+    > 1 | try {} catch ({cause: {message}}) {}␊
+        |               ^^^^^^^^^^^^^^^^^^ Remove unused catch binding.␊
+    `