Bug 1430173 - Add Timer Rounding tests backported from -central to -esr. r=baku, a=RyanVM

MozReview-Commit-ID: Jl4WZAamgrI

--HG--
extra : transplant_source : E%DC%91lU%1C%A4l%2C%C8%23PCz%EB%F2%81%25%1F%90

dom/tests/browser/browser_performanceAPI.js

@@ -0,0 +1,139 @@
+/**
+ * Bug 1369303 - A test for making sure that performance APIs have been correctly
+ *   spoofed or disabled.
+ */
+
+const TEST_PATH = "http://example.net/browser/" +
+                  "dom/tests/browser/";
+
+const PERFORMANCE_TIMINGS = [
+  "navigationStart",
+  "unloadEventStart",
+  "unloadEventEnd",
+  "redirectStart",
+  "redirectEnd",
+  "fetchStart",
+  "domainLookupStart",
+  "domainLookupEnd",
+  "connectStart",
+  "connectEnd",
+  "requestStart",
+  "responseStart",
+  "responseEnd",
+  "domLoading",
+  "domInteractive",
+  "domContentLoadedEventStart",
+  "domContentLoadedEventEnd",
+  "domComplete",
+  "loadEventStart",
+  "loadEventEnd",
+];
+
+let isRounded = (x, expectedPrecision) => {
+  let rounded = (Math.floor(x / expectedPrecision) * expectedPrecision);
+  // First we do the perfectly normal check that should work just fine
+  if (rounded === x || x === 0)
+    return true;
+
+  // When we're diving by non-whole numbers, we may not get perfect
+  // multiplication/division because of floating points
+  if (Math.abs(rounded - x + expectedPrecision) < .0000001) {
+    return true;
+  } else if (Math.abs(rounded - x) < .0000001) {
+    return true;
+  }
+
+  // Then we handle the case where you're sub-millisecond and the timer is not
+  // We check that the timer is not sub-millisecond by assuming it is not if it
+  // returns an even number of milliseconds
+  if (expectedPrecision < 1 && Math.round(x) == x) {
+    if (Math.round(rounded) == x) {
+      return true;
+    }
+  }
+
+  ok(false, "Looming Test Failure, Additional Debugging Info: Expected Precision: " + expectedPrecision + " Measured Value: " + x +
+    " Rounded Vaue: " + rounded + " Fuzzy1: " + Math.abs(rounded - x + expectedPrecision) +
+    " Fuzzy 2: " + Math.abs(rounded - x));
+
+  return false;
+};
+
+// ================================================================================================
+// ================================================================================================
+add_task(function* () {
+  let tab = yield BrowserTestUtils.openNewForegroundTab(
+    gBrowser, TEST_PATH + "dummy.html");
+
+  yield ContentTask.spawn(tab.linkedBrowser, {
+      list: PERFORMANCE_TIMINGS,
+      precision: 2,
+      isRoundedFunc: isRounded.toString()
+    }, (data) => {
+    let timerlist = data.list;
+    let expectedPrecision = data.precision;
+    // eslint beleives that isrounded is available in this scope, but if you
+    // remove the assignment, you will see it is not
+    // eslint-disable-next-line
+    let isRounded = eval(data.isRoundedFunc);
+
+    // Check that whether the performance timing API is correctly spoofed.
+    for (let time of timerlist) {
+      ok(isRounded(content.performance.timing[time], expectedPrecision), `For reduceTimerPrecision(` + expectedPrecision + `), the timing(${time}) is not correctly rounded: ` + content.performance.timing[time]);
+    }
+
+    // Try to add some entries.
+    content.performance.mark("Test");
+    content.performance.mark("Test-End");
+    content.performance.measure("Test-Measure", "Test", "Test-End");
+
+    // Check the entries for performance.getEntries/getEntriesByType/getEntriesByName.
+    is(content.performance.getEntries().length, 3, "For reduceTimerPrecision, there should be 3 entries for performance.getEntries()");
+    for (var i = 0; i < 3; i++) {
+      let startTime = content.performance.getEntries()[i].startTime;
+      let duration = content.performance.getEntries()[i].duration;
+      ok(isRounded(startTime, expectedPrecision), "For reduceTimerPrecision(" + expectedPrecision + "), performance.getEntries(" + i + ").startTime is not rounded: " + startTime);
+      ok(isRounded(duration, expectedPrecision), "For reduceTimerPrecision(" + expectedPrecision + "), performance.getEntries(" + i + ").duration is not rounded: " + duration);
+    }
+    is(content.performance.getEntriesByType("mark").length, 2, "For reduceTimerPrecision, there should be 2 entries for performance.getEntriesByType()");
+    is(content.performance.getEntriesByName("Test", "mark").length, 1, "For reduceTimerPrecision, there should be 1 entry for performance.getEntriesByName()");
+    content.performance.clearMarks();
+    content.performance.clearMeasures();
+    content.performance.clearResourceTimings();
+  });
+  gBrowser.removeTab(tab);
+});
+
+// ================================================================================================
+// ================================================================================================
+add_task(function*() {
+  let tab = yield BrowserTestUtils.openNewForegroundTab(
+    gBrowser, TEST_PATH + "dummy.html");
+
+  yield ContentTask.spawn(tab.linkedBrowser, {
+    list: PERFORMANCE_TIMINGS,
+    precision: 2,
+    isRoundedFunc: isRounded.toString()
+  }, (data) => {
+    let expectedPrecision = data.precision;
+    let workerCall = data.workerCall;
+    return new Promise(resolve => {
+      let worker = new content.Worker("file_workerPerformance.js");
+      worker.onmessage = function(e) {
+        if (e.data.type == "status") {
+          ok(e.data.status, e.data.msg);
+        } else if (e.data.type == "finish") {
+          worker.terminate();
+          resolve();
+        } else {
+          ok(false, "Unknown message type");
+          worker.terminate();
+          resolve();
+        }
+      };
+    worker.postMessage({precision: expectedPrecision});
+    });
+  });
+
+  gBrowser.removeTab(tab);
+});