Libraries: Move to Userland/Libraries/

Author: https://github.com/awesomekling
Commit: 13d7c09125

Userland/Libraries/LibJS/Tests/functions/function-duplicate-parameters.js

@@ -0,0 +1,45 @@
+test("function with duplicate parameter names", () => {
+    function foo(bar, _, bar) {
+        return bar;
+    }
+    expect(foo(1, 2, 3)).toBe(3);
+});
+
+test("syntax errors", () => {
+    // Regular function in strict mode
+    expect(`
+        "use strict";
+        function foo(bar, bar) {}
+    `).not.toEval();
+
+    // Arrow function in strict mode
+    expect(`
+        "use strict";
+        const foo = (bar, bar) => {};
+    `).not.toEval();
+
+    // Arrow function in non-strict mode
+    expect(`
+        const foo = (bar, bar) => {};
+    `).not.toEval();
+
+    // Regular function with rest parameter
+    expect(`
+        function foo(bar, ...bar) {}
+    `).not.toEval();
+
+    // Arrow function with rest parameter
+    expect(`
+        const foo = (bar, ...bar) => {};
+    `).not.toEval();
+
+    // Regular function with default parameter
+    expect(`
+        function foo(bar, bar = 1) {}
+    `).not.toEval();
+
+    // Arrow function with default parameter
+    expect(`
+        const foo = (bar, bar = 1) => {};
+    `).not.toEval();
+});