test: add performance object test

Author: edusperoni

TestRunner/app/tests/RuntimeImplementedAPIs.js

@@ -16,3 +16,31 @@ describe("Runtime exposes", function () {
     expect(Math.abs(dateDelta - timeDelta)).toBeLessThan(dateDelta * 0.25);
   });
 });
+
+describe("Performance object", () => {
+  it("should be available", () => {
+    expect(performance).toBeDefined();
+  });
+  it("should have a now function", () => {
+    expect(performance.now).toBeDefined();
+  });
+  it("should have a now function that returns a number", () => {
+    expect(typeof performance.now()).toBe("number");
+  });
+  it("should have timeOrigin", () => {
+    expect(performance.timeOrigin).toBeDefined();
+  });
+  it("should have timeOrigin that is a number", () => {
+    expect(typeof performance.timeOrigin).toBe("number");
+  });
+  it("should have timeOrigin that is greater than 0", () => {
+    expect(performance.timeOrigin).toBeGreaterThan(0);
+  });
+  it("should be close to the current time", () => {
+    const dateNow = Date.now();
+    const performanceNow = performance.now();
+    const timeOrigin = performance.timeOrigin;
+    const performanceAccurateNow = timeOrigin + performanceNow;
+    expect(Math.abs(dateNow - performanceAccurateNow)).toBeLessThan(10);
+  });
+});