Factor out common code in distiller page browser test.

ExecuteJsScript() is used only once in this CL but will be used in
new tests added by https://crrev.com/c/1922788.

This CL also runs clang-format on pinch_tester.js and modifies it to
return a bool instead of a dict. The latter simplifies verification
of script execution in the C++ portion of the test.

Bug: 1016615
Change-Id: I2c847eb53556a30e991d988fb676c6a3fa5aee8a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1971702
Commit-Queue: Aran Gilman <gilmanmh@google.com>
Reviewed-by: Wei-Yin Chen (陳威尹) <wychen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#726585}

components/dom_distiller/content/browser/distiller_page_web_contents_browsertest.cc

@@ -83,6 +83,24 @@ namespace dom_distiller {
 
 const char* kSimpleArticlePath = "/simple_article.html";
 const char* kVideoArticlePath = "/video_article.html";
+const char* kDistilledPagePath = "/distilled_page.html";
+
+void 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();
+  ASSERT_EQ(base::Value::Type::BOOLEAN, result.type());
+  EXPECT_TRUE(result.GetBool());
+}
 
 class DistillerPageWebContentsTest : public ContentBrowserTest {
  public:
@@ -112,11 +130,6 @@ class DistillerPageWebContentsTest : public ContentBrowserTest {
     quit_closure.Run();
   }
 
-  void OnJsExecutionDone(base::Closure callback, base::Value value) {
-    js_result_ = std::move(value);
-    callback.Run();
-  }
-
  private:
   void AddComponentsResources() {
     base::FilePath pak_file;
@@ -143,7 +156,7 @@ class DistillerPageWebContentsTest : public ContentBrowserTest {
         path.AppendASCII("components/dom_distiller/core/javascript"));
 
     response_ = std::make_unique<net::test_server::ControllableHttpResponse>(
-        embedded_test_server(), "/pinch_tester.html");
+        embedded_test_server(), kDistilledPagePath);
 
     ASSERT_TRUE(embedded_test_server()->Start());
   }
@@ -155,7 +168,6 @@ class DistillerPageWebContentsTest : public ContentBrowserTest {
 
   DistillerPageWebContents* distiller_page_;
   std::unique_ptr<proto::DomDistillerResult> distiller_result_;
-  base::Value js_result_;
 
   std::unique_ptr<net::test_server::ControllableHttpResponse> response_;
 };
@@ -533,7 +545,7 @@ IN_PROC_BROWSER_TEST_F(DistillerPageWebContentsTest, MAYBE_TestPinch) {
   WebContentsMainFrameHelper main_frame_loaded(
       web_contents, url_loaded_runner.QuitClosure(), true);
   web_contents->GetController().LoadURL(
-      embedded_test_server()->GetURL("/pinch_tester.html"), content::Referrer(),
+      embedded_test_server()->GetURL(kDistilledPagePath), content::Referrer(),
       ui::PAGE_TRANSITION_TYPED, std::string());
 
   const std::string html_template = viewer::GetArticleTemplateHtml(
@@ -550,19 +562,7 @@ IN_PROC_BROWSER_TEST_F(DistillerPageWebContentsTest, MAYBE_TestPinch) {
   response_->Done();
   url_loaded_runner.Run();
 
-  // Execute the JS to run the tests, and wait until it has finished.
-  base::RunLoop run_loop;
-  web_contents->GetMainFrame()->ExecuteJavaScriptForTests(
-      base::UTF8ToUTF16("(function() {return pinchtest.run();})();"),
-      base::BindOnce(&DistillerPageWebContentsTest::OnJsExecutionDone,
-                     base::Unretained(this), run_loop.QuitClosure()));
-  run_loop.Run();
-
-  ASSERT_TRUE(js_result_.is_dict());
-
-  base::Optional<bool> value = js_result_.FindBoolKey("success");
-  ASSERT_TRUE(value.has_value());
-  EXPECT_TRUE(value.value());
+  ExecuteJsScript(web_contents, "pinchtest.run()");
 }
 
 }  // namespace dom_distiller

components/test/data/dom_distiller/pinch_tester.js

@@ -7,15 +7,15 @@ const pinchtest = (function() {
 
   function assertTrue(condition, message) {
     if (!condition) {
-      message = message || "Assertion failed";
+      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";
+    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);
@@ -50,7 +50,7 @@ const pinchtest = (function() {
 
   function assertEqual(a, b, message) {
     if (!isEquivalent(a, b)) {
-      message = message || "Assertion failed";
+      message = message || 'Assertion failed';
       console.log('"', a, '" and "', b, '" are not equal');
       console.trace();
       throw new Error(message);
@@ -62,22 +62,17 @@ const pinchtest = (function() {
     const points = {};
     function lowestID() {
       let ans = -1;
-      for(const key in points) {
+      for (const key in points) {
         ans = Math.max(ans, key);
       }
       return ans + 1;
     }
-    function changeTouchPoint (key, x, y, offsetX, offsetY) {
-      const e = {
-        clientX: x,
-        clientY: y,
-        pageX: x,
-        pageY: y
-      };
-      if (typeof(offsetX) === 'number') {
+    function changeTouchPoint(key, x, y, offsetX, offsetY) {
+      const e = {clientX: x, clientY: y, pageX: x, pageY: y};
+      if (typeof (offsetX) === 'number') {
         e.clientX += offsetX;
       }
-      if (typeof(offsetY) === 'number') {
+      if (typeof (offsetY) === 'number') {
         e.clientY += offsetY;
       }
       points[key] = e;
@@ -92,13 +87,10 @@ const pinchtest = (function() {
       },
       events: function() {
         const arr = [];
-        for(const key in points) {
+        for (const key in points) {
           arr.push(points[key]);
         }
-        return {
-          touches: arr,
-          preventDefault: function(){}
-        };
+        return {touches: arr, preventDefault: function() {}};
       }
     };
   });
@@ -414,7 +406,7 @@ const pinchtest = (function() {
   }
 
   return {
-    run: function(){
+    run: function() {
       testZoomOut();
       testZoomIn();
       testZoomOutAndPan();
@@ -427,7 +419,7 @@ const pinchtest = (function() {
       testFontScaling();
       pincher.reset();
 
-      return {success: true};
+      return true;
     }
   };
 }());