Adds tests for checking interstitials

lighthouse-core/audits/interstitial.js

@@ -0,0 +1,54 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'use strict';
+
+const Audit = require('./audit');
+
+class Interstitial extends Audit {
+  /**
+   * @return {!AuditMeta}
+   */
+  static get meta() {
+    return {
+      category: 'UX',
+      name: 'interstitial',
+      description: 'The page does not place interstitials over the page content',
+      requiredArtifacts: ['Interstitial']
+    };
+  }
+
+  /**
+   * @param {!Artifacts} artifacts
+   * @return {!AuditResult}
+   */
+  static audit(artifacts) {
+    if (typeof artifacts.Interstitial === 'undefined' ||
+        !Array.isArray(artifacts.Interstitial)) {
+      return Interstitial.generateAuditResult({
+        rawValue: false,
+        debugString: 'Unable to retrieve element information.'
+      });
+    }
+
+    return Interstitial.generateAuditResult({
+      rawValue: (artifacts.Interstitial.length === 0)
+    });
+  }
+}
+
+module.exports = Interstitial;

lighthouse-core/config/default.json

@@ -16,7 +16,8 @@
       "critical-request-chains",
       "speedline",
       "content-width",
-      "cache-contents"
+      "cache-contents",
+      "interstitial"
     ]
   },
   {
@@ -65,7 +66,8 @@
     "label",
     "tabindex",
     "content-width",
-    "cache-start-url"
+    "cache-start-url",
+    "interstitial"
   ],
 
   "aggregations": [{
@@ -230,6 +232,10 @@
         "content-width": {
           "value": true,
           "weight": 1
+        },
+        "interstitial": {
+          "value": true,
+          "weight": 1
         }
       }
     }]

lighthouse-core/driver/gatherers/interstitial.js

@@ -0,0 +1,66 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+const Gather = require('./gather');
+
+/* global window, document, __returnResults */
+
+/* istanbul ignore next */
+function getInterstitial() {
+  const viewportSize = window.outerWidth * window.outerHeight;
+
+  // Walk the tree of elements
+  const candidates = [...document.querySelectorAll('*')]
+    .filter(e => {
+      // Check for position fixed.
+      const isFixed = window.getComputedStyle(e).position === 'fixed';
+
+      // Check for nav elements.
+      const regExpNav = /menu|nav|sidebar|drawer/i;
+      const isNav = regExpNav.test(e.className) || regExpNav.test(e.id);
+
+      // Get the size of the element.
+      const eBCR = e.getBoundingClientRect();
+      const size = eBCR.width * eBCR.height;
+
+      // Only allow through fixed, non-nav elements whose size makes them cover
+      // over 50% of the available viewport.
+      return isFixed && !isNav && (size / viewportSize > 0.5);
+    });
+
+  // __returnResults is injected by evaluateAsync for passing back the result.
+  __returnResults(candidates);
+}
+
+class Interstitial extends Gather {
+
+  afterPass(options) {
+    const driver = options.driver;
+
+    return driver.evaluateAsync(`(${getInterstitial.toString()}())`)
+
+    .then(returnedValue => {
+      this.artifact = returnedValue;
+    }, _ => {
+      this.artifact = -1;
+      return;
+    });
+  }
+}
+
+module.exports = Interstitial;

lighthouse-core/test/audits/intersitial.js

@@ -0,0 +1,45 @@
+/**
+ * Copyright 2016 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+const Audit = require('../../audits/interstitial.js');
+const assert = require('assert');
+
+/* global describe, it*/
+
+describe('Mobile-friendly: interstitial audit', () => {
+  it('fails when no input present', () => {
+    return assert.equal(Audit.audit({}).rawValue, false);
+  });
+
+  it('fails when input is of incorrect type', () => {
+    return assert.equal(Audit.audit({
+      Interstitial: 3
+    }).rawValue, false);
+  });
+
+  it('fails when element array is non-empty', () => {
+    return assert.equal(Audit.audit({
+      Interstitial: [
+        'x'
+      ]
+    }).rawValue, false);
+  });
+
+  it('passes when widths match', () => {
+    return assert.equal(Audit.audit({
+      Interstitial: []
+    }).rawValue, true);
+  });
+});

lighthouse-core/test/driver/gatherers/interstitial.js

@@ -0,0 +1,56 @@
+/**
+ * Copyright 2016 Google Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+/* eslint-env mocha */
+
+const InterstitialGatherer = require('../../../driver/gatherers/interstitial');
+const assert = require('assert');
+let interstitialGatherer;
+
+describe('Interstitial gatherer', () => {
+  // Reset the Gatherer before each test.
+  beforeEach(() => {
+    interstitialGatherer = new InterstitialGatherer();
+  });
+
+  it('returns an artifact', () => {
+    return interstitialGatherer.afterPass({
+      driver: {
+        evaluateAsync() {
+          return Promise.resolve(['test']);
+        }
+      }
+    }).then(_ => {
+      assert.ok(Array.isArray(interstitialGatherer.artifact));
+      assert.equal(interstitialGatherer.artifact.length, 1);
+    });
+  });
+
+  it('handles driver failure', () => {
+    return interstitialGatherer.afterPass({
+      driver: {
+        evaluateAsync() {
+          return Promise.reject('such a fail');
+        }
+      }
+    }).then(_ => {
+      assert(false);
+    }).catch(_ => {
+      assert.equal(interstitialGatherer.artifact, -1);
+    });
+  });
+});