core: add new base artifact, HostFormFactor

lighthouse-cli/test/smokehouse/test-definitions/dobetterweb/dbw-expectations.js

@@ -12,6 +12,7 @@
 const expectations = [
   {
     artifacts: {
+      HostFormFactor: 'desktop',
       Stacks: [{
         id: 'jquery',
       }, {

lighthouse-core/gather/gather-runner.js

@@ -456,14 +456,15 @@ class GatherRunner {
 
     const {emulatedFormFactor} = options.settings;
     // Whether Lighthouse was run on a mobile device (i.e. not on a desktop machine).
-    const IsMobileHost = hostUserAgent.includes('Android') || hostUserAgent.includes('Mobile');
+    const HostFormFactor = /android|mobile/i.test(hostUserAgent) ? 'mobile' : 'desktop';
     const TestedAsMobileDevice = emulatedFormFactor === 'mobile' ||
-      (emulatedFormFactor !== 'desktop' && IsMobileHost);
+      (emulatedFormFactor !== 'desktop' && HostFormFactor === 'mobile');
 
     return {
       fetchTime: (new Date()).toJSON(),
       LighthouseRunWarnings: [],
       TestedAsMobileDevice,
+      HostFormFactor,
       HostUserAgent: hostUserAgent,
       NetworkUserAgent: '', // updated later
       BenchmarkIndex: 0, // updated later

lighthouse-core/scripts/build-report-for-autodeployment.js

@@ -77,6 +77,7 @@ async function generateErrorLHR() {
       `Something went wrong with recording the trace over your page load. Please run Lighthouse again. (NO_FCP)`, // eslint-disable-line max-len
     ],
     TestedAsMobileDevice: true,
+    HostFormFactor: 'desktop',
     HostUserAgent: 'Mozilla/5.0 ErrorUserAgent Chrome/66',
     NetworkUserAgent: 'Mozilla/5.0 ErrorUserAgent Chrome/66',
     BenchmarkIndex: 1000,

lighthouse-core/test/gather/gather-runner-test.js

@@ -234,6 +234,32 @@ describe('GatherRunner', function() {
     });
   });
 
+  describe.only('collects HostFormFactor as an artifact', () => {
+    const requestedUrl = 'https://example.com';
+
+    function test(name, userAgent, expectedValue) {
+      it(name, async () => {
+        const driver = Object.assign({}, fakeDriver, {
+          getBrowserVersion() {
+            return Promise.resolve({userAgent: 'Android'});
+          },
+        });
+        const config = new Config({
+          passes: [],
+          settings: {},
+        });
+        const options = {requestedUrl, driver, settings: config.settings};
+
+        const results = await GatherRunner.run(config.passes, options);
+        expect(results.HostFormFactor).toBe('mobile');
+      });
+    }
+
+    test('works when running on mobile device', 'some mobile ua', 'mobile');
+    test('works when running on android device', 'some android ua', 'mobile');
+    test('works when running on desktop device', 'some desktop ua', 'desktop');
+  });
+
   it('sets up the driver to begin emulation when all emulation flags are undefined', () => {
     const tests = {
       calledDeviceEmulation: false,

types/artifacts.d.ts

@@ -29,6 +29,8 @@ declare global {
       LighthouseRunWarnings: string[];
       /** Whether the page was loaded on either a real or emulated mobile device. */
       TestedAsMobileDevice: boolean;
+      /** Device which Chrome is running on. */
+      HostFormFactor: 'desktop'|'mobile';
       /** The user agent string of the version of Chrome used. */
       HostUserAgent: string;
       /** The user agent string that Lighthouse used to load the page. */