MD Settings: Adding some unit tests for <settings-main>.

chrome/test/data/webui/settings/settings_main_test.js

Index: chrome/test/data/webui/settings/settings_main_test.js
diff --git a/chrome/test/data/webui/settings/settings_main_test.js b/chrome/test/data/webui/settings/settings_main_test.js
new file mode 100644
index 0000000000000000000000000000000000000000..5a1baef07e6ec043a496da5ae0646e29a8b6c196
--- /dev/null
+++ b/chrome/test/data/webui/settings/settings_main_test.js
@@ -0,0 +1,98 @@
+// Copyright 2016 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.
+
+cr.define('settings_main_page', function() {
+  /**
+   * @implements {SearchManager}
+   */
+  var TestSearchManager = function() {
+    /** @private {boolean} */
+    this.matchesFound_ = true;
+  }
+
+  TestSearchManager.prototype = {
+    /**
+     * @param {boolean} matchesFound
+     */
+    setMatchesFound: function(matchesFound) {
+      this.matchesFound_ = matchesFound;
+    },
+
+    /** @override */
+    search: function(text, page) {
+      var searchRequest = new settings.SearchRequest(text);
+      searchRequest.finished = true;
+      searchRequest.updateMatches(this.matchesFound_);
+      searchRequest.resolver.resolve(searchRequest);
+      return searchRequest.resolver.promise;
+    },
+  };
+
+  function registerTests() {

[michaelpg, 2016/07/30 05:38:44]

nit: new tests shouldn't use the cr.define/registerTests() paradigm -- just call
the suite functions here at the top level (or inside an IIFE if you like), and
the TEST_F merely calls mocha.run.

see route_tests.js 

[dpapad, 2016/08/02 22:33:15]

Unfortunately removing the registerTests() call, messes up with the
initialization timing and ends up in a console error

[20719:20719:0802/151025:INFO:CONSOLE(47)] "Uncaught ReferenceError: settings is
not defined", source: settings_main_test.js (51)

Because route.js is evaled after line 47.

+    var settingsPrefs = null;
+
+    suiteSetup(function() {
+      settingsPrefs = document.createElement('settings-prefs');
+    });
+
+    suite('SearchTests', function() {
+      /** @type {?TestSearchManager} */
+      var searchManager = null;
+
+      /** @type {?SettingsMainElement} */
+      var page = null;

[michaelpg, 2016/07/30 05:38:44]

nit: page already has too many meaninsg

[dpapad, 2016/08/02 22:33:15]

Done.

+
+      // TODO(tommycli): Remove once settings.navigateTo is no longer a stub.
+      settings.navigateTo = function(route) {
+        page.currentRoute = route;
+      };
+
+      setup(function() {
+        searchManager = new TestSearchManager();
+        settings.setSearchManagerForTesting(searchManager);
+        PolymerTest.clearBody();
+        page = document.createElement('settings-main');
+        page.prefs = settingsPrefs.prefs;
+        page.toolbarSpinnerActive = false;
+        document.body.appendChild(page);
+      });
+
+      teardown(function() { page.remove(); });
+
+      test('NoResultsPageShowsHides', function() {

[michaelpg, 2016/07/30 05:38:44]

nit... this is just a string, it doesn't have to be CamelCase -- 'no results
page shows and hides' is friendlier

[dpapad, 2016/08/02 22:33:15]

Done.

+        var noSearchResults = page.$.noSearchResults;
+        assertTrue(!!noSearchResults);
+        assertTrue(noSearchResults.hidden);
+
+        searchManager.setMatchesFound(false);
+        return page.searchContents('foo').then(function() {
+          assertFalse(noSearchResults.hidden);
+
+          searchManager.setMatchesFound(true);
+          return page.searchContents('foo');
+        }).then(function() {
+          assertTrue(noSearchResults.hidden);
+        });
+      });
+
+      // Ensure that when the user clears the search box, the "no results" page
+      // is hidden.
+      test('NoResultsPageHidesOnClear', function() {
+        var noSearchResults = page.$.noSearchResults;
+        assertTrue(!!noSearchResults);
+        assertTrue(noSearchResults.hidden);
+        searchManager.setMatchesFound(false);

[michaelpg, 2016/07/30 05:38:44]

assert first that noSearchResults is unhidden?

[michaelpg, 2016/08/02 20:45:20]

ping, did you miss this file? this one is slightly higher priority than a nit
:-)

to catch a bug where setMatchesFound(false) would hide noSearchResults

[dpapad, 2016/08/02 22:33:15]

I don't fully understand your comment "to catch a bug where
setMatchesFound(false) would hide noSearchResults"

When the searchContents() is invoked with an empty string, there are no matches
found, but the "no results" page should still remain hidden. In other words, the
behavior you describe as a "bug" is the expected behavior here, and this test
ensures it is happening.

It really does not matter what the prior state of noSearchResult visibility is.
Once searchContents() executes it will decide whether to hide or show the
noResultsPage (by updating the showNoResultsFound_ boolean.

+
+        // Clearing the search box is effectively a search for the empty string.
+        return page.searchContents('').then(function() {
+          assertTrue(noSearchResults.hidden);
+        });
+      });
+    });
+  }
+
+  return {
+    registerTests: registerTests,
+  };
+});