Fix: prefer-object-spread false positives with accessors (fixes #12086)…

… (#12784)

lib/rules/prefer-object-spread.js

@@ -25,6 +25,36 @@ function hasArraySpread(node) {
     return node.arguments.some(arg => arg.type === "SpreadElement");
 }
 
+/**
+ * Determines whether the given node is an accessor property (getter/setter).
+ * @param {ASTNode} node Node to check.
+ * @returns {boolean} `true` if the node is a getter or a setter.
+ */
+function isAccessorProperty(node) {
+    return node.type === "Property" &&
+        (node.kind === "get" || node.kind === "set");
+}
+
+/**
+ * Determines whether the given object expression node has accessor properties (getters/setters).
+ * @param {ASTNode} node `ObjectExpression` node to check.
+ * @returns {boolean} `true` if the node has at least one getter/setter.
+ */
+function hasAccessors(node) {
+    return node.properties.some(isAccessorProperty);
+}
+
+/**
+ * Determines whether the given call expression node has object expression arguments with accessor properties (getters/setters).
+ * @param {ASTNode} node `CallExpression` node to check.
+ * @returns {boolean} `true` if the node has at least one argument that is an object expression with at least one getter/setter.
+ */
+function hasArgumentsWithAccessors(node) {
+    return node.arguments
+        .filter(arg => arg.type === "ObjectExpression")
+        .some(hasAccessors);
+}
+
 /**
  * Helper that checks if the node needs parentheses to be valid JS.
  * The default is to wrap the node in parentheses to avoid parsing errors.
@@ -249,7 +279,11 @@ module.exports = {
                     if (
                         node.arguments.length >= 1 &&
                         node.arguments[0].type === "ObjectExpression" &&
-                        !hasArraySpread(node)
+                        !hasArraySpread(node) &&
+                        !(
+                            node.arguments.length > 1 &&
+                            hasArgumentsWithAccessors(node)
+                        )
                     ) {
                         const messageId = node.arguments.length === 1
                             ? "useLiteralMessage"

tests/lib/rules/prefer-object-spread.js

@@ -59,7 +59,19 @@ ruleTester.run("prefer-object-spread", rule, {
         `
         import { Object, Array } from 'globals';
         Object.assign({ foo: 'bar' });
-        `
+        `,
+
+        // ignore Object.assign() with > 1 arguments if any of the arguments is an object expression with a getter/setter
+        "Object.assign({ get a() {} }, {})",
+        "Object.assign({ set a(val) {} }, {})",
+        "Object.assign({ get a() {} }, foo)",
+        "Object.assign({ set a(val) {} }, foo)",
+        "Object.assign({ foo: 'bar', get a() {}, baz: 'quux' }, quuux)",
+        "Object.assign({ foo: 'bar', set a(val) {} }, { baz: 'quux' })",
+        "Object.assign({}, { get a() {} })",
+        "Object.assign({}, { set a(val) {} })",
+        "Object.assign({}, { foo: 'bar', get a() {} }, {})",
+        "Object.assign({ foo }, bar, {}, { baz: 'quux', set a(val) {}, quuux }, {})"
     ],
 
     invalid: [
@@ -834,6 +846,20 @@ ruleTester.run("prefer-object-spread", rule, {
                     column: 1
                 }
             ]
+        },
+
+        // report Object.assign() with getters/setters if the function call has only 1 argument
+        {
+            code: "Object.assign({ get a() {}, set b(val) {} })",
+            output: "({get a() {}, set b(val) {}})",
+            errors: [
+                {
+                    messageId: "useLiteralMessage",
+                    type: "CallExpression",
+                    line: 1,
+                    column: 1
+                }
+            ]
         }
     ]
 });