fix: improve autofix for the prefer-const rule (#16292)

* fix: avoid incorrect autofix in the `prefer-const` rule * test: add more test cases * test: add more cases * fix: improve autofix and add more cases
eslint · Sep 12, 2022 · 734b54e · 734b54e
1 parent 6a923ff
commit 734b54e
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diff --git a/lib/rules/prefer-const.js b/lib/rules/prefer-const.js
@@ -446,7 +446,19 @@ module.exports = {
 
                         reportCount += nodesToReport.length;
 
-                        shouldFix = shouldFix && (reportCount === varDeclParent.declarations.length);
+                        let totalDeclarationsCount = 0;
+
+                        varDeclParent.declarations.forEach(declaration => {
+                            if (declaration.id.type === "ObjectPattern") {
+                                totalDeclarationsCount += declaration.id.properties.length;
+                            } else if (declaration.id.type === "ArrayPattern") {
+                                totalDeclarationsCount += declaration.id.elements.length;
+                            } else {
+                                totalDeclarationsCount += 1;
+                            }
+                        });
+
+                        shouldFix = shouldFix && (reportCount === totalDeclarationsCount);
                     }
                 }
 

diff --git a/tests/lib/rules/prefer-const.js b/tests/lib/rules/prefer-const.js
@@ -684,6 +684,78 @@ ruleTester.run("prefer-const", rule, {
             errors: [
                 { messageId: "useConst", data: { name: "a" }, type: "Identifier" }
             ]
+        },
+
+        // https://github.com/eslint/eslint/issues/16266
+        {
+            code: `
+            let { itemId, list } = {},
+            obj = [],
+            total = 0;
+            total = 9;
+            console.log(itemId, list, obj, total);
+            `,
+            output: null,
+            options: [{ destructuring: "any", ignoreReadBeforeAssign: true }],
+            parserOptions: { ecmaVersion: 2022 },
+            errors: [
+                { messageId: "useConst", data: { name: "itemId" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "list" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "obj" }, type: "Identifier" }
+            ]
+        },
+        {
+            code: `
+            let { itemId, list } = {},
+            obj = [];
+            console.log(itemId, list, obj);
+            `,
+            output: `
+            const { itemId, list } = {},
+            obj = [];
+            console.log(itemId, list, obj);
+            `,
+            options: [{ destructuring: "any", ignoreReadBeforeAssign: true }],
+            parserOptions: { ecmaVersion: 2022 },
+            errors: [
+                { messageId: "useConst", data: { name: "itemId" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "list" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "obj" }, type: "Identifier" }
+            ]
+        },
+        {
+            code: `
+            let [ itemId, list ] = [],
+            total = 0;
+            total = 9;
+            console.log(itemId, list, total);
+            `,
+            output: null,
+            options: [{ destructuring: "any", ignoreReadBeforeAssign: true }],
+            parserOptions: { ecmaVersion: 2022 },
+            errors: [
+                { messageId: "useConst", data: { name: "itemId" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "list" }, type: "Identifier" }
+            ]
+        },
+        {
+            code: `
+            let [ itemId, list ] = [],
+            obj = [];
+            console.log(itemId, list, obj);
+            `,
+            output: `
+            const [ itemId, list ] = [],
+            obj = [];
+            console.log(itemId, list, obj);
+            `,
+            options: [{ destructuring: "any", ignoreReadBeforeAssign: true }],
+            parserOptions: { ecmaVersion: 2022 },
+            errors: [
+                { messageId: "useConst", data: { name: "itemId" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "list" }, type: "Identifier" },
+                { messageId: "useConst", data: { name: "obj" }, type: "Identifier" }
+            ]
         }
     ]
 });