Revert "Refactor Reader Mode's JavaScript tests to use Mocha."

This reverts commit 7de90169.

Reason for revert: Suspicious to have broken DomDistillerViewerSourceBrowserTest.UISetsPrefs in browser_tests.
https://ci.chromium.org/p/chromium/builders/ci/Linux%20Chromium%20OS%20ASan%20LSan%20Tests%20%281%29/37476


Original change's description:
> Refactor Reader Mode's JavaScript tests to use Mocha.
> 
> The tests did not previously use an established test framework, making
> tasks like executing certain code before or after every test and testing
> asynchronous code more difficult. It should also be easier for
> developers familiar with JavaScript testing in general and WebUI testing
> in particular to read and write JavaScript tests for DOM Distiller and
> Reader Mode.
> 
> Follow-up work includes replacing the custom assert methods with Chai,
> as well as writing more tests to cover existing functionality.
> 
> Bug: 1027612
> Change-Id: I39acc923a0424881d2694281d9aa0323c8f9a913
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1992504
> Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
> Commit-Queue: Aran Gilman <gilmanmh@google.com>
> Cr-Commit-Position: refs/heads/master@{#762551}

TBR=wychen@chromium.org,gilmanmh@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1027612
Change-Id: I78b6b82e98c8f47951ab88e2056595de878f1ab1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2166219Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Yuki Shiino <yukishiino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762720}

components/BUILD.gn

@@ -561,7 +561,6 @@ if (!is_ios && !is_fuchsia) {
       "security_state/content/testdata/",
       "//content/test/data/",
       "//third_party/dom_distiller_js/dist/test/data/",
-      "//third_party/mocha",
     ]
 
     deps = [

components/dom_distiller/content/browser/test/distilled_page_js_browsertest.cc

@@ -22,6 +22,22 @@
 namespace dom_distiller {
 namespace {
 
+base::Value ExecuteJsScript(content::WebContents* web_contents,
+                            const std::string& script) {
+  base::Value result;
+  base::RunLoop run_loop;
+  web_contents->GetMainFrame()->ExecuteJavaScriptForTests(
+      base::UTF8ToUTF16(script),
+      base::BindOnce(
+          [](base::Closure callback, base::Value* out, base::Value result) {
+            (*out) = std::move(result);
+            callback.Run();
+          },
+          run_loop.QuitClosure(), &result));
+  run_loop.Run();
+  return result;
+}
+
 class DistilledPageJsTest : public content::ContentBrowserTest {
  protected:
   explicit DistilledPageJsTest()
@@ -37,13 +53,14 @@ class DistilledPageJsTest : public content::ContentBrowserTest {
     distilled_page_ = SetUpTestServerWithDistilledPage(embedded_test_server());
   }
 
-  void LoadAndExecuteTestScript(const std::string& file) {
+  void LoadAndExecuteTestScript(const std::string& file,
+                                const std::string& fixture_name) {
     distilled_page_->AppendScriptFile(file);
     distilled_page_->Load(embedded_test_server(), shell()->web_contents());
-    bool allTestsPassed;
-    ASSERT_TRUE(content::ExecuteScriptAndExtractBool(
-        shell()->web_contents(), "mocha.run()", &allTestsPassed));
-    EXPECT_TRUE(allTestsPassed);
+    const base::Value result = ExecuteJsScript(
+        shell()->web_contents(), base::StrCat({fixture_name, ".run()"}));
+    ASSERT_EQ(base::Value::Type::BOOLEAN, result.type());
+    EXPECT_TRUE(result.GetBool());
   }
 
   std::unique_ptr<FakeDistilledPage> distilled_page_;
@@ -55,7 +72,7 @@ class DistilledPageJsTest : public content::ContentBrowserTest {
 #define MAYBE_Pinch Pinch
 #endif
 IN_PROC_BROWSER_TEST_F(DistilledPageJsTest, MAYBE_Pinch) {
-  LoadAndExecuteTestScript("pinch_tester.js");
+  LoadAndExecuteTestScript("pinch_tester.js", "pinchtest");
 }
 
 }  // namespace

components/dom_distiller/content/browser/test/test_util.cc

@@ -39,12 +39,10 @@ const char* kDistilledPagePath = "/distilled_page.html";
 void SetUpTestServerWithoutStarting(EmbeddedTestServer* server) {
   FilePath root_dir;
   PathService::Get(base::DIR_SOURCE_ROOT, &root_dir);
-
-  server->ServeFilesFromDirectory(
-      root_dir.AppendASCII("components/dom_distiller/core/javascript"));
   server->ServeFilesFromDirectory(
       root_dir.AppendASCII("components/test/data/dom_distiller"));
-  server->ServeFilesFromDirectory(root_dir.AppendASCII("third_party/mocha"));
+  server->ServeFilesFromDirectory(
+      root_dir.AppendASCII("components/dom_distiller/core/javascript"));
 }
 
 }  // namespace
@@ -60,8 +58,6 @@ FakeDistilledPage::FakeDistilledPage(EmbeddedTestServer* server)
   // DomDistillerRequestViewBase::SendCommonJavaScript(); however, this method
   // is impractical to use in testing.
   AppendScriptFile("dom_distiller_viewer.js");
-  AppendScriptFile("mocha.js");
-  AppendScriptFile("test_util.js");
 }
 
 FakeDistilledPage::~FakeDistilledPage() = default;

components/test/data/dom_distiller/pinch_tester.js

@@ -2,7 +2,6 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(gilmanmh): Consider replacing this with dispatched touch events.
 class Touch {
   constructor() {
     this.points = {};
@@ -45,61 +44,64 @@ class Touch {
   }
 }
 
-// TODO(gilmanmh): Replace these helpers with Chai's equivalents.
-function assertTrue(condition, message) {
-  if (!condition) {
-    message = message || 'Assertion failed';
-    console.trace();
-    throw new Error(message);
+class PinchTest {
+  /** @private */
+  assertTrue_(condition, message) {
+    if (!condition) {
+      message = message || 'Assertion failed';
+      console.trace();
+      throw new Error(message);
+    }
   }
-}
 
-function assertClose(a, b, message) {
-  if (Math.abs(a - b) > 1e-5) {
-    message = message || 'Assertion failed';
-    console.log('"', a, '" and "', b, '" are not close.');
-    console.trace();
-    throw new Error(message);
-  }
-}
-
-function isEquivalent(a, b) {
-  // Create arrays of property names
-  const aProps = Object.getOwnPropertyNames(a);
-  const bProps = Object.getOwnPropertyNames(b);
-
-  // If number of properties is different,
-  // objects are not equivalent
-  if (aProps.length != bProps.length) {
-    return false;
+  /** @private */
+  assertClose_(a, b, message) {
+    if (Math.abs(a - b) > 1e-5) {
+      message = message || 'Assertion failed';
+      console.log('"', a, '" and "', b, '" are not close.');
+      console.trace();
+      throw new Error(message);
+    }
   }
 
-  for (let i = 0; i < aProps.length; i++) {
-    const propName = aProps[i];
+  /** @private */
+  isEquivalent_(a, b) {
+    // Create arrays of property names
+    const aProps = Object.getOwnPropertyNames(a);
+    const bProps = Object.getOwnPropertyNames(b);
 
-    // If values of same property are not equal,
+    // If number of properties is different,
     // objects are not equivalent
-    if (a[propName] !== b[propName]) {
+    if (aProps.length != bProps.length) {
       return false;
     }
-  }
 
-  // If we made it this far, objects
-  // are considered equivalent
-  return true;
-}
+    for (let i = 0; i < aProps.length; i++) {
+      const propName = aProps[i];
+
+      // If values of same property are not equal,
+      // objects are not equivalent
+      if (a[propName] !== b[propName]) {
+        return false;
+      }
+    }
 
-function assertEqual(a, b, message) {
-  if (!isEquivalent(a, b)) {
-    message = message || 'Assertion failed';
-    console.log('"', a, '" and "', b, '" are not equal');
-    console.trace();
-    throw new Error(message);
+    // If we made it this far, objects
+    // are considered equivalent
+    return true;
+  }
+
+  /** @private */
+  assertEqual_(a, b, message) {
+    if (!this.isEquivalent_(a, b)) {
+      message = message || 'Assertion failed';
+      console.log('"', a, '" and "', b, '" are not equal');
+      console.trace();
+      throw new Error(message);
+    }
   }
-}
 
-suite('Pincher', function() {
-  test('Zoom Out', function() {
+  testZoomOut() {
     pincher.reset();
     const t = new Touch();
 
@@ -107,57 +109,57 @@ suite('Pincher', function() {
     let oldState = pincher.status();
     t.addTouchPoint(100, 100);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(300, 300);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     // Make sure extra move event doesn't change state
     pincher.handleTouchMove(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     t.updateTouchPoint(0, 150, 150);
     t.updateTouchPoint(1, 250, 250);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale < 0.9);
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
 
     // Make sure end event doesn't change state
     oldState = pincher.status();
     t.releaseTouchPoint(1);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
-  });
+    this.assertEqual_(oldState, pincher.status());
+  }
 
-  test('Zoom In', function() {
+  testZoomIn() {
     pincher.reset();
     const t = new Touch();
 
     let oldState = pincher.status();
     t.addTouchPoint(150, 150);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(250, 250);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     t.updateTouchPoint(0, 100, 100);
     t.updateTouchPoint(1, 300, 300);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale > 1.1);
+    this.assertTrue_(pincher.status().clampedScale > 1.1);
 
     oldState = pincher.status();
     t.releaseTouchPoint(1);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
-  });
+    this.assertEqual_(oldState, pincher.status());
+  }
 
-  test('Zomm Out And Pan', function() {
+  testZoomOutAndPan() {
     pincher.reset();
     const t = new Touch();
     t.addTouchPoint(100, 100);
@@ -175,12 +177,12 @@ suite('Pincher', function() {
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
 
-    assertClose(pincher.status().shiftX, 10);
-    assertClose(pincher.status().shiftY, -5);
-    assertTrue(pincher.status().clampedScale < 0.9);
-  });
+    this.assertClose_(pincher.status().shiftX, 10);
+    this.assertClose_(pincher.status().shiftY, -5);
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
+  }
 
-  test('Reversible', function() {
+  testReversible() {
     pincher.reset();
     const t = new Touch();
     t.addTouchPoint(100, 100);
@@ -205,26 +207,26 @@ suite('Pincher', function() {
     pincher.handleTouchEnd(t.events());
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
-    assertClose(pincher.status().clampedScale, 1);
-  });
+    this.assertClose_(pincher.status().clampedScale, 1);
+  }
 
-  test('Multitouch Zoom Out', function() {
+  testMultitouchZoomOut() {
     pincher.reset();
     const t = new Touch();
 
     let oldState = pincher.status();
     t.addTouchPoint(100, 100);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(300, 300);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(100, 300);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(300, 100);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     // Multi-touch zoom out.
     t.updateTouchPoint(0, 150, 150);
@@ -236,60 +238,60 @@ suite('Pincher', function() {
     oldState = pincher.status();
     t.releaseTouchPoint(3);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(2);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(1);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
-    assertTrue(pincher.status().clampedScale < 0.9);
-  });
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
+  }
 
-  test('Zoom Out Then Multi', function() {
+  testZoomOutThenMulti() {
     pincher.reset();
     const t = new Touch();
 
     let oldState = pincher.status();
     t.addTouchPoint(100, 100);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.addTouchPoint(300, 300);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     // Zoom out.
     t.updateTouchPoint(0, 150, 150);
     t.updateTouchPoint(1, 250, 250);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale < 0.9);
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
 
     // Make sure adding and removing more point doesn't change state
     oldState = pincher.status();
     t.addTouchPoint(600, 600);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
     t.releaseTouchPoint(2);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     // More than two fingers.
     t.addTouchPoint(150, 250);
     pincher.handleTouchStart(t.events());
     t.addTouchPoint(250, 150);
     pincher.handleTouchStart(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     t.updateTouchPoint(0, 100, 100);
     t.updateTouchPoint(1, 300, 300);
     t.updateTouchPoint(2, 100, 300);
     t.updateTouchPoint(3, 300, 100);
     pincher.handleTouchMove(t.events());
-    assertClose(pincher.status().scale, 1);
+    this.assertClose_(pincher.status().scale, 1);
 
     oldState = pincher.status();
     t.releaseTouchPoint(3);
@@ -297,10 +299,10 @@ suite('Pincher', function() {
     t.releaseTouchPoint(1);
     t.releaseTouchPoint(0);
     pincher.handleTouchEnd(t.events());
-    assertEqual(oldState, pincher.status());
-  });
+    this.assertEqual_(oldState, pincher.status());
+  }
 
-  test('Cancel', function() {
+  testCancel() {
     pincher.reset();
     const t = new Touch();
 
@@ -311,13 +313,13 @@ suite('Pincher', function() {
     t.updateTouchPoint(0, 150, 150);
     t.updateTouchPoint(1, 250, 250);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale < 0.9);
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
 
     const oldState = pincher.status();
     t.releaseTouchPoint(1);
     t.releaseTouchPoint(0);
     pincher.handleTouchCancel(t.events());
-    assertEqual(oldState, pincher.status());
+    this.assertEqual_(oldState, pincher.status());
 
     t.addTouchPoint(150, 150);
     pincher.handleTouchStart(t.events());
@@ -326,10 +328,10 @@ suite('Pincher', function() {
     t.updateTouchPoint(0, 100, 100);
     t.updateTouchPoint(1, 300, 300);
     pincher.handleTouchMove(t.events());
-    assertClose(pincher.status().clampedScale, 1);
-  });
+    this.assertClose_(pincher.status().clampedScale, 1);
+  }
 
-  test('Singularity', function() {
+  testSingularity() {
     pincher.reset();
     const t = new Touch();
 
@@ -340,14 +342,14 @@ suite('Pincher', function() {
     t.updateTouchPoint(0, 150, 150);
     t.updateTouchPoint(1, 50, 50);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale > 1.1);
-    assertTrue(pincher.status().clampedScale < 100);
-    assertTrue(pincher.status().scale < 100);
+    this.assertTrue_(pincher.status().clampedScale > 1.1);
+    this.assertTrue_(pincher.status().clampedScale < 100);
+    this.assertTrue_(pincher.status().scale < 100);
 
     pincher.handleTouchCancel();
-  });
+  }
 
-  test('Min Span', function() {
+  testMinSpan() {
     pincher.reset();
     const t = new Touch();
 
@@ -358,17 +360,17 @@ suite('Pincher', function() {
     t.updateTouchPoint(0, 100, 100);
     t.updateTouchPoint(1, 100, 100);
     pincher.handleTouchMove(t.events());
-    assertTrue(pincher.status().clampedScale < 0.9);
-    assertTrue(pincher.status().clampedScale > 0);
-    assertTrue(pincher.status().scale > 0);
+    this.assertTrue_(pincher.status().clampedScale < 0.9);
+    this.assertTrue_(pincher.status().clampedScale > 0);
+    this.assertTrue_(pincher.status().scale > 0);
 
     pincher.handleTouchCancel();
-  });
+  }
 
-  test('Font Scaling', function() {
+  testFontScaling() {
     pincher.reset();
     useFontScaling(1.5);
-    assertClose(pincher.status().clampedScale, 1.5);
+    this.assertClose_(pincher.status().clampedScale, 1.5);
 
     let t = new Touch();
 
@@ -385,11 +387,12 @@ suite('Pincher', function() {
     pincher.handleTouchMove(t.events());
 
     // Verify scale is smaller.
-    assertTrue(pincher.status().clampedScale < 0.9 * oldState.clampedScale);
+    this.assertTrue_(
+        pincher.status().clampedScale < 0.9 * oldState.clampedScale);
     pincher.handleTouchCancel();
 
     useFontScaling(0.8);
-    assertClose(pincher.status().clampedScale, 0.8);
+    this.assertClose_(pincher.status().clampedScale, 0.8);
 
     // Start touch.
     t = new Touch();
@@ -405,7 +408,25 @@ suite('Pincher', function() {
     pincher.handleTouchMove(t.events());
 
     // Verify scale is larger.
-    assertTrue(pincher.status().clampedScale > 1.1 * oldState.clampedScale);
+    this.assertTrue_(
+        pincher.status().clampedScale > 1.1 * oldState.clampedScale);
     pincher.handleTouchCancel();
-  });
-});
+  }
+
+  run() {
+    this.testZoomOut();
+    this.testZoomIn();
+    this.testZoomOutAndPan();
+    this.testReversible();
+    this.testMultitouchZoomOut();
+    this.testZoomOutThenMulti();
+    this.testCancel();
+    this.testSingularity();
+    this.testMinSpan();
+    this.testFontScaling();
+    pincher.reset();
+
+    return true;
+  }
+}
+const pinchtest = new PinchTest;

components/test/data/dom_distiller/test_util.js

-// Copyright 2020 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Based on BrowserTestReporter() in //chrome/test/data/webui/mocha_adapter.js
-// TODO(crbug.com/1027612): Look into using that class directly.
-function TestReporter(runner) {
-  let passes = 0;
-  let failures = 0;
-
-  runner.on('pass', function(test) {
-    passes++;
-  });
-
-  runner.on('fail', function(test, err) {
-    failures++;
-    let message = 'Mocha test failed: ' + test.fullTitle() + '\n';
-
-    // Remove unhelpful mocha lines from stack trace.
-    if (err.stack) {
-      const stack = err.stack.split('\n');
-      for (let i = 0; i < stack.length; i++) {
-        if (stack[i].indexOf('mocha.js:') == -1) {
-          message += stack[i] + '\n';
-        }
-      }
-    } else {
-      message += err.toString();
-    }
-
-    console.error(message);
-  });
-
-  runner.on('end', function() {
-    window.domAutomationController.send(failures === 0 && passes > 0);
-  });
-}
-
-mocha.setup({
-  ui: 'tdd',
-  reporter: TestReporter,
-  enableTimeouts: false,
-});