1 files changed, 89 insertions, 0 deletions
diff --git a/browser/components/newtab/test/unit/content-src/lib/perf-service.test.js b/browser/components/newtab/test/unit/content-src/lib/perf-service.test.js
new file mode 100644
index 0000000000..9cabfb5029
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+++ b/browser/components/newtab/test/unit/content-src/lib/perf-service.test.js
@@ -0,0 +1,89 @@
+/* globals assert, beforeEach, describe, it */
+import { _PerfService } from "content-src/lib/perf-service";
+import { FakePerformance } from "test/unit/utils.js";
+
+let perfService;
+
+describe("_PerfService", () => {
+  let sandbox;
+  let fakePerfObj;
+
+  beforeEach(() => {
+    sandbox = sinon.createSandbox();
+    fakePerfObj = new FakePerformance();
+    perfService = new _PerfService({ performanceObj: fakePerfObj });
+  });
+
+  afterEach(() => {
+    sandbox.restore();
+  });
+
+  describe("#absNow", () => {
+    it("should return a number > the time origin", () => {
+      const absNow = perfService.absNow();
+
+      assert.isAbove(absNow, perfService.timeOrigin);
+    });
+  });
+  describe("#getEntriesByName", () => {
+    it("should call getEntriesByName on the appropriate Window.performance", () => {
+      sandbox.spy(fakePerfObj, "getEntriesByName");
+
+      perfService.getEntriesByName("monkey", "mark");
+
+      assert.calledOnce(fakePerfObj.getEntriesByName);
+      assert.calledWithExactly(fakePerfObj.getEntriesByName, "monkey", "mark");
+    });
+
+    it("should return entries with the given name", () => {
+      sandbox.spy(fakePerfObj, "getEntriesByName");
+      perfService.mark("monkey");
+      perfService.mark("dog");
+
+      let marks = perfService.getEntriesByName("monkey", "mark");
+
+      assert.isArray(marks);
+      assert.lengthOf(marks, 1);
+      assert.propertyVal(marks[0], "name", "monkey");
+    });
+  });
+
+  describe("#getMostRecentAbsMarkStartByName", () => {
+    it("should throw an error if there is no mark with the given name", () => {
+      function bogusGet() {
+        perfService.getMostRecentAbsMarkStartByName("rheeeet");
+      }
+
+      assert.throws(bogusGet, Error, /No marks with the name/);
+    });
+
+    it("should return the Number from the most recent mark with the given name + the time origin", () => {
+      perfService.mark("dog");
+      perfService.mark("dog");
+
+      let absMarkStart = perfService.getMostRecentAbsMarkStartByName("dog");
+
+      // 2 because we want the result of the 2nd call to mark, and an instance
+      // of FakePerformance just returns the number of time mark has been
+      // called.
+      assert.equal(absMarkStart - perfService.timeOrigin, 2);
+    });
+  });
+
+  describe("#mark", () => {
+    it("should call the wrapped version of mark", () => {
+      sandbox.spy(fakePerfObj, "mark");
+
+      perfService.mark("monkey");
+
+      assert.calledOnce(fakePerfObj.mark);
+      assert.calledWithExactly(fakePerfObj.mark, "monkey");
+    });
+  });
+
+  describe("#timeOrigin", () => {
+    it("should get the origin of the wrapped performance object", () => {
+      assert.equal(perfService.timeOrigin, fakePerfObj.timeOrigin);
+    });
+  });
+});