LibJS: Move tests to /Tests/LibJS

Author: https://github.com/gmta
Commit: https://github.com/LadybirdBrowser/ladybird/commit/e3faa9b5add
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/7572
Reviewed-by: https://github.com/trflynn89 ✅

Tests/LibJS/Runtime/builtins/Array/array-basic.js

@@ -0,0 +1,65 @@
+test("basic functionality", () => {
+    var a = [1, 2, 3];
+
+    expect(typeof a).toBe("object");
+    expect(a).toHaveLength(3);
+    expect(a[0]).toBe(1);
+    expect(a[1]).toBe(2);
+    expect(a[2]).toBe(3);
+
+    a[1] = 5;
+    expect(a[1]).toBe(5);
+    expect(a).toHaveLength(3);
+
+    a.push(7);
+    expect(a[3]).toBe(7);
+    expect(a).toHaveLength(4);
+
+    a = [,];
+    expect(a).toHaveLength(1);
+    expect(a.toString()).toBe("");
+    expect(a[0]).toBeUndefined();
+
+    a = [, , , ,];
+    expect(a).toHaveLength(4);
+    expect(a.toString()).toBe(",,,");
+    expect(a[0]).toBeUndefined();
+    expect(a[1]).toBeUndefined();
+    expect(a[2]).toBeUndefined();
+    expect(a[3]).toBeUndefined();
+
+    a = [1, , 2, , , 3];
+    expect(a).toHaveLength(6);
+    expect(a.toString()).toBe("1,,2,,,3");
+    expect(a[0]).toBe(1);
+    expect(a[1]).toBeUndefined();
+    expect(a[2]).toBe(2);
+    expect(a[3]).toBeUndefined();
+    expect(a[4]).toBeUndefined();
+    expect(a[5]).toBe(3);
+
+    a = [1, , 2, , , 3];
+    Object.defineProperty(a, 1, {
+        get() {
+            return this.getterSetterValue;
+        },
+        set(value) {
+            this.getterSetterValue = value;
+        },
+    });
+    expect(a).toHaveLength(6);
+    expect(a.toString()).toBe("1,,2,,,3");
+    expect(a.getterSetterValue).toBeUndefined();
+    a[1] = 20;
+    expect(a).toHaveLength(6);
+    expect(a.toString()).toBe("1,20,2,,,3");
+    expect(a.getterSetterValue).toBe(20);
+});
+
+test("assigning array expression with destination referenced in array expression", () => {
+    function go(i) {
+        var i = [i];
+        return i;
+    }
+    expect(go("foo")).toEqual(["foo"]);
+});