LibJS: Reorganize tests into subfolders

Libraries/LibJS/Tests/functions/function-rest-params.js

@@ -0,0 +1,57 @@
+load("test-common.js");
+
+try {
+    function foo(...a) {
+        assert(a instanceof Array);
+        assert(a.length === 0);
+    }
+    foo();
+
+    function foo1(...a) {
+        assert(a instanceof Array);
+        assert(a.length === 4);
+        assert(a[0] === "foo");
+        assert(a[1] === 123);
+        assert(a[2] === undefined);
+        assert(a[3].foo === "bar");
+    }
+    foo1("foo", 123, undefined, { foo: "bar" });
+
+    function foo2(a, b, ...c) {
+        assert(a === "foo");
+        assert(b === 123);
+        assert(c instanceof Array);
+        assert(c.length === 0);
+    }
+    foo2("foo", 123);
+
+    function foo3(a, b, ...c) {
+        assert(a === "foo");
+        assert(b === 123);
+        assert(c instanceof Array);
+        assert(c.length === 2);
+        assert(c[0] === undefined);
+        assert(c[1].foo === "bar");
+    }
+    foo3("foo", 123, undefined, { foo: "bar" });
+
+    var foo = (...a) => {
+        assert(a instanceof Array);
+        assert(a.length === 0);
+    };
+    foo();
+
+    var foo = (a, b, ...c) => {
+        assert(a === "foo");
+        assert(b === 123);
+        assert(c instanceof Array);
+        assert(c.length === 2);
+        assert(c[0] === undefined);
+        assert(c[1].foo === "bar");
+    };
+    foo("foo", 123, undefined, { foo: "bar" });
+
+    console.log("PASS");
+} catch (e) {
+    console.log("FAIL: " + e);
+}