Chore: reflect review comments (refs eslint#12545)

t-mangoe · Mar 27, 2021 · 44be9d3 · 44be9d3
1 parent bcf8026
commit 44be9d3
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Showing 3 changed files with 48 additions and 8 deletions.
diff --git a/docs/rules/no-multi-assign.md b/docs/rules/no-multi-assign.md
@@ -47,15 +47,32 @@ let b = c;
 
 This rule has an object option:
 
-* `"ignoreNonDeclaration": false` (default) disallows using multiple assignments to already declared variables.
+* `"ignoreNonDeclaration"`: When set to `true`, the rule allows chains that don't include initializing a variable in a declaration. Default is `false`.
+
+### ignoreNonDeclaration
 
 Examples of **correct** code for the `{ "ignoreNonDeclaration": true }` option:
 
 ```js
 /*eslint no-multi-assign: ["error", { ignoreNonDeclaration: true }]*/
+
+let a;
+let b;
+a = b = "baz";
+
 const x = {};
 const y = {};
-x.one = y.one = 1; // this is allowed.
+x.one = y.one = 1;
+```
+
+Examples of **incorrect** code for the `{ "ignoreNonDeclaration": true }` option:
+
+```js
+/*eslint no-multi-assign: ["error", { ignoreNonDeclaration: true }]*/
+
+let a = b = "baz";
+
+const foo = bar = 1;
 ```
 
 ## Related Rules

diff --git a/lib/rules/no-multi-assign.js b/lib/rules/no-multi-assign.js
@@ -45,12 +45,11 @@ module.exports = {
         const options = context.options[0] || {
             ignoreNonDeclaration: false
         };
+        const targetParent = options.ignoreNonDeclaration ? ["VariableDeclarator"] : ["AssignmentExpression", "VariableDeclarator"];
 
         return {
             AssignmentExpression(node) {
-                const target = options.ignoreNonDeclaration ? ["VariableDeclarator"] : ["AssignmentExpression", "VariableDeclarator"];
-
-                if (target.indexOf(node.parent.type) !== -1) {
+                if (targetParent.indexOf(node.parent.type) !== -1) {
                     context.report({
                         node,
                         messageId: "unexpectedChain"

diff --git a/tests/lib/rules/no-multi-assign.js b/tests/lib/rules/no-multi-assign.js
@@ -39,7 +39,6 @@ function errorAt(line, column, type) {
 //------------------------------------------------------------------------------
 
 const ruleTester = new RuleTester();
-const options = [{ ignoreNonDeclaration: true }];
 
 ruleTester.run("no-mutli-assign", rule, {
     valid: [
@@ -53,7 +52,8 @@ ruleTester.run("no-mutli-assign", rule, {
         { code: "for(const a = 0, b = 0;;){}", parserOptions: { ecmaVersion: 6 } },
         { code: "export let a, b;", parserOptions: { ecmaVersion: 6, sourceType: "module" } },
         { code: "export let a,\n b = 0;", parserOptions: { ecmaVersion: 6, sourceType: "module" } },
-        { code: "const x = {};const y = {};x.one = y.one = 1;", options, parserOptions: { ecmaVersion: 6 } }
+        { code: "const x = {};const y = {};x.one = y.one = 1;", options: [{ ignoreNonDeclaration: true }], parserOptions: { ecmaVersion: 6 } },
+        { code: "let a, b;a = b = 1", options: [{ ignoreNonDeclaration: true }], parserOptions: { ecmaVersion: 6 } }
     ],
 
     invalid: [
@@ -142,12 +142,36 @@ ruleTester.run("no-mutli-assign", rule, {
         },
         {
             code: "const x = {};\nconst y = x.one = 1;",
-            options,
+            options: [{ ignoreNonDeclaration: true }],
             parserOptions: { ecmaVersion: 6 },
             errors: [
                 errorAt(2, 11, "AssignmentExpression")
             ]
 
+        },
+        {
+            code: "let a, b;a = b = 1",
+            options: [{}],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                errorAt(1, 14, "AssignmentExpression")
+            ]
+        },
+        {
+            code: "let x, y;x = y = 'baz'",
+            options: [{ ignoreNonDeclaration: false }],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                errorAt(1, 14, "AssignmentExpression")
+            ]
+        },
+        {
+            code: "const a = b = 1",
+            options: [{ ignoreNonDeclaration: true }],
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                errorAt(1, 11, "AssignmentExpression")
+            ]
         }
     ]
 });