core: replace WebInspector traceparser with native JSON.parse (#6099)

lighthouse-core/lib/asset-saver.js

@@ -12,7 +12,6 @@ const stream = require('stream');
 const Simulator = require('./dependency-graph/simulator/simulator');
 const lanternTraceSaver = require('./lantern-trace-saver');
 const Metrics = require('./traces/pwmetrics-events');
-const TraceParser = require('./traces/trace-parser');
 const rimraf = require('rimraf');
 const mkdirp = require('mkdirp');
 
@@ -94,30 +93,20 @@ async function loadArtifacts(basePath) {
 
   // load devtoolsLogs
   artifacts.devtoolsLogs = {};
-  filenames.filter(f => f.endsWith(devtoolsLogSuffix)).map(filename => {
+  filenames.filter(f => f.endsWith(devtoolsLogSuffix)).forEach(filename => {
     const passName = filename.replace(devtoolsLogSuffix, '');
     const devtoolsLog = JSON.parse(fs.readFileSync(path.join(basePath, filename), 'utf8'));
     artifacts.devtoolsLogs[passName] = devtoolsLog;
   });
 
   // load traces
   artifacts.traces = {};
-  const promises = filenames.filter(f => f.endsWith(traceSuffix)).map(filename => {
-    return new Promise(resolve => {
-      const passName = filename.replace(traceSuffix, '');
-      const readStream = fs.createReadStream(path.join(basePath, filename), {
-        encoding: 'utf-8',
-        highWaterMark: 4 * 1024 * 1024, // TODO benchmark to find the best buffer size here
-      });
-      const parser = new TraceParser();
-      readStream.on('data', chunk => parser.parseChunk(chunk));
-      readStream.on('end', _ => {
-        artifacts.traces[passName] = parser.getTrace();
-        resolve();
-      });
-    });
+  filenames.filter(f => f.endsWith(traceSuffix)).forEach(filename => {
+    const file = fs.readFileSync(path.join(basePath, filename), {encoding: 'utf-8'});
+    const trace = JSON.parse(file);
+    const passName = filename.replace(traceSuffix, '');
+    artifacts.traces[passName] = Array.isArray(trace) ? {traceEvents: trace} : trace;
   });
-  await Promise.all(promises);
 
   return artifacts;
 }

lighthouse-core/lib/web-inspector.js

@@ -21,10 +21,6 @@ module.exports = (function() {
     global.self = global;
   }
 
-  if (typeof global.window === 'undefined') {
-    global.window = global;
-  }
-
   global.Node = {
     ELEMENT_NODE: 1,
     TEXT_NODE: 3,
@@ -45,28 +41,11 @@ module.exports = (function() {
   // See https://github.com/GoogleChrome/lighthouse/issues/73
   const _setImmediate = global.setImmediate;
 
-  global.Protocol = {
-    Agents() {},
-  };
-
   global.WebInspector = {};
   const WebInspector = global.WebInspector;
 
   // Shared Dependencies
-  require('chrome-devtools-frontend/front_end/common/Object.js');
-  require('chrome-devtools-frontend/front_end/common/UIString.js');
   require('chrome-devtools-frontend/front_end/platform/utilities.js');
-  require('chrome-devtools-frontend/front_end/sdk/Target.js');
-  require('chrome-devtools-frontend/front_end/sdk/TargetManager.js');
-
-  // Dependencies for timeline-model
-  WebInspector.console = {
-    error() {},
-  };
-
-  // used for streaming json parsing
-  require('chrome-devtools-frontend/front_end/common/TextUtils.js');
-  require('chrome-devtools-frontend/front_end/timeline/TimelineLoader.js');
 
   // Dependencies for effective CSS rule calculation.
   require('chrome-devtools-frontend/front_end/common/TextRange.js');

lighthouse-core/test/lib/asset-saver-test.js

@@ -170,4 +170,15 @@ describe('asset-saver helper', () => {
         });
     }, 40 * 1000);
   });
+
+  describe('loadArtifacts', () => {
+    it('loads artifacts from disk', async () => {
+      const artifactsPath = __dirname + '/../fixtures/artifacts/perflog/';
+      const artifacts = await assetSaver.loadArtifacts(artifactsPath);
+      assert.strictEqual(artifacts.LighthouseRunWarnings.length, 2);
+      assert.strictEqual(artifacts.URL.requestedUrl, 'https://www.reddit.com/r/nba');
+      assert.strictEqual(artifacts.devtoolsLogs.defaultPass.length, 555);
+      assert.strictEqual(artifacts.traces.defaultPass.traceEvents.length, 12);
+    });
+  });
 });

lighthouse-extension/app/src/lighthouse-ext-background.js

@@ -231,8 +231,8 @@ function isRunning() {
   return lighthouseIsRunning;
 }
 
-// Run when in extension context, but not in devtools.
-if ('chrome' in window && chrome.runtime) {
+// Run when in extension context, but not in devtools or unit tests.
+if (typeof window !== 'undefined' && 'chrome' in window && chrome.runtime) {
   chrome.runtime.onInstalled.addListener(details => {
     if (details.previousVersion) {
       // eslint-disable-next-line no-console

package.json

@@ -8,7 +8,7 @@
     "chrome-debug": "./lighthouse-core/scripts/manual-chrome-launcher.js"
   },
   "engines": {
-    "node": ">=8.9"
+    "node": ">=8.10"
   },
   "scripts": {
     "install-all": "npm-run-posix-or-windows install-all:task",