Update: add ignoreNonDeclaration to no-multi-assign rule (fixes #12545)

lib/rules/no-multi-assign.js

@@ -21,7 +21,16 @@ module.exports = {
             url: "https://eslint.org/docs/rules/no-multi-assign"
         },
 
-        schema: [],
+        schema: [{
+            type: "object",
+            properties: {
+                ignoreNonDeclaration: {
+                    type: "boolean",
+                    default: false
+                }
+            },
+            additionalProperties: false
+        }],
 
         messages: {
             unexpectedChain: "Unexpected chained assignment."
@@ -33,10 +42,15 @@ module.exports = {
         //--------------------------------------------------------------------------
         // Public
         //--------------------------------------------------------------------------
+        const options = context.options[0] || {
+            ignoreNonDeclaration: false
+        };
 
         return {
             AssignmentExpression(node) {
-                if (["AssignmentExpression", "VariableDeclarator"].indexOf(node.parent.type) !== -1) {
+                const target = options.ignoreNonDeclaration ? ["VariableDeclarator"] : ["AssignmentExpression", "VariableDeclarator"];
+
+                if (target.indexOf(node.parent.type) !== -1) {
                     context.report({
                         node,
                         messageId: "unexpectedChain"

tests/lib/rules/no-multi-assign.js

@@ -39,6 +39,7 @@ function errorAt(line, column, type) {
 //------------------------------------------------------------------------------
 
 const ruleTester = new RuleTester();
+const options = [{ ignoreNonDeclaration: true }];
 
 ruleTester.run("no-mutli-assign", rule, {
     valid: [
@@ -51,7 +52,8 @@ ruleTester.run("no-mutli-assign", rule, {
         { code: "for(let a = 0, b = 0;;){}", parserOptions: { ecmaVersion: 6 } },
         { 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: "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 } }
     ],
 
     invalid: [
@@ -137,6 +139,15 @@ ruleTester.run("no-mutli-assign", rule, {
             errors: [
                 errorAt(1, 5, "AssignmentExpression")
             ]
+        },
+        {
+            code: "const x = {};\nconst y = x.one = 1;",
+            options,
+            parserOptions: { ecmaVersion: 6 },
+            errors: [
+                errorAt(2, 11, "AssignmentExpression")
+            ]
+
         }
     ]
 });