LibJS: Implement Date.prototype.setUTCSeconds

Userland/Libraries/LibJS/Tests/builtins/Date/Date.prototype.setUTCSeconds.js

@@ -0,0 +1,46 @@
+describe("errors", () => {
+    test("called on non-Date object", () => {
+        expect(() => {
+            Date.prototype.setUTCSeconds();
+        }).toThrowWithMessage(TypeError, "Not an object of type Date");
+    });
+
+    test("called with non-numeric parameters", () => {
+        expect(() => {
+            new Date().setUTCSeconds(Symbol.hasInstance);
+        }).toThrowWithMessage(TypeError, "Cannot convert symbol to number");
+
+        expect(() => {
+            new Date().setUTCSeconds(1989, Symbol.hasInstance);
+        }).toThrowWithMessage(TypeError, "Cannot convert symbol to number");
+    });
+});
+
+describe("correct behavior", () => {
+    const d = new Date(2000, 2, 1);
+
+    test("basic functionality", () => {
+        d.setUTCSeconds(50);
+        expect(d.getUTCSeconds()).toBe(50);
+
+        d.setUTCSeconds(50, 600);
+        expect(d.getUTCSeconds()).toBe(50);
+        expect(d.getUTCMilliseconds()).toBe(600);
+
+        d.setUTCSeconds("");
+        expect(d.getUTCSeconds()).toBe(0);
+
+        d.setUTCSeconds("a");
+        expect(d.getUTCSeconds()).toBe(NaN);
+    });
+
+    test("NaN", () => {
+        d.setUTCSeconds(NaN);
+        expect(d.getUTCSeconds()).toBeNaN();
+    });
+
+    test("time clip", () => {
+        d.setUTCSeconds(8.65e15);
+        expect(d.getUTCSeconds()).toBeNaN();
+    });
+});