From 487bee6652fb3780f54bd05c4767fbd72eaca7cf Mon Sep 17 00:00:00 2001
From: Lorenzo Urbini <superluglor@gmail.com>
Date: Wed, 18 Oct 2017 01:15:05 +0200
Subject: [PATCH] core(errors-in-console): include runtime exceptions (#3494)

---
 .../test/fixtures/dobetterweb/dbw_tester.html |  3 +
 .../dobetterweb/dbw-expectations.js           |  6 +-
 lighthouse-core/audits/errors-in-console.js   | 33 ++++++---
 lighthouse-core/config/default.js             |  1 +
 .../gather/gatherers/runtime-exceptions.js    | 38 ++++++++++
 .../test/audits/errors-in-console-test.js     | 34 ++++++++-
 .../gatherers/runtime-exceptions-test.js      | 72 +++++++++++++++++++
 7 files changed, 173 insertions(+), 14 deletions(-)
 create mode 100644 lighthouse-core/gather/gatherers/runtime-exceptions.js
 create mode 100644 lighthouse-core/test/gather/gatherers/runtime-exceptions-test.js

diff --git a/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html b/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html
index 1bdd9f121884..209c7f22ea0d 100644
--- a/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html
+++ b/lighthouse-cli/test/fixtures/dobetterweb/dbw_tester.html
@@ -35,6 +35,9 @@
 <!-- FAIL: block rendering -->
 <script src="./dbw_tester.js"></script>
 
+<!-- FAIL(errors-in-console): exception thrown -->
+<script type="text/javascript">throw new Error('An error');</script>
+
 <style>
   body {
     color: #000;
diff --git a/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js b/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js
index e17b6a3f05b1..1c998ae3ac78 100644
--- a/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js
+++ b/lighthouse-cli/test/smokehouse/dobetterweb/dbw-expectations.js
@@ -15,11 +15,11 @@ module.exports = [
     audits: {
       'errors-in-console': {
         score: false,
-        rawValue: 3,
-        displayValue: '3',
+        rawValue: 4,
+        displayValue: '4',
         details: {
           items: {
-            length: 3,
+            length: 4,
           },
         },
       },
diff --git a/lighthouse-core/audits/errors-in-console.js b/lighthouse-core/audits/errors-in-console.js
index 63981f2dcf61..fbec0a88655c 100644
--- a/lighthouse-core/audits/errors-in-console.js
+++ b/lighthouse-core/audits/errors-in-console.js
@@ -24,7 +24,7 @@ class ErrorLogs extends Audit {
       helpText: 'Errors logged to the console indicate unresolved problems. ' +
         'They can come from network request failures and other browser concerns.',
       failureDescription: 'Browser errors were logged to the console',
-      requiredArtifacts: ['ChromeConsoleMessages'],
+      requiredArtifacts: ['ChromeConsoleMessages', 'RuntimeExceptions'],
     };
   }
 
@@ -33,14 +33,29 @@ class ErrorLogs extends Audit {
    * @return {!AuditResult}
    */
   static audit(artifacts) {
-    const entries = artifacts.ChromeConsoleMessages;
-    const tableRows = entries.filter(log => log.entry.level === 'error').map(item => {
-      return {
-        source: item.entry.source,
-        description: item.entry.text,
-        url: item.entry.url,
-      };
-    });
+    const consoleEntries = artifacts.ChromeConsoleMessages;
+    const runtimeExceptions = artifacts.RuntimeExceptions;
+    const consoleRows =
+      consoleEntries.filter(log => log.entry && log.entry.level === 'error')
+      .map(item => {
+        return {
+          source: item.entry.source,
+          description: item.entry.text,
+          url: item.entry.url,
+        };
+      });
+
+    const runtimeExRows =
+      runtimeExceptions.filter(entry => entry.exceptionDetails !== undefined)
+      .map(entry => {
+        return {
+          source: 'Runtime.exception',
+          description: entry.exceptionDetails.exception.description,
+          url: entry.exceptionDetails.url,
+        };
+      });
+
+    const tableRows = consoleRows.concat(runtimeExRows);
 
     const headings = [
       {key: 'url', itemType: 'url', text: 'URL'},
diff --git a/lighthouse-core/config/default.js b/lighthouse-core/config/default.js
index df2998efc5e8..c2321c28b6dd 100644
--- a/lighthouse-core/config/default.js
+++ b/lighthouse-core/config/default.js
@@ -22,6 +22,7 @@ module.exports = {
       'viewport-dimensions',
       'theme-color',
       'manifest',
+      'runtime-exceptions',
       'chrome-console-messages',
       'image-usage',
       'accessibility',
diff --git a/lighthouse-core/gather/gatherers/runtime-exceptions.js b/lighthouse-core/gather/gatherers/runtime-exceptions.js
new file mode 100644
index 000000000000..c47e5edd785d
--- /dev/null
+++ b/lighthouse-core/gather/gatherers/runtime-exceptions.js
@@ -0,0 +1,38 @@
+/**
+ * @license Copyright 2017 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.
+ */
+
+/**
+ * @fileoverview Gathers runtime exceptions.
+ */
+
+'use strict';
+
+const Gatherer = require('./gatherer');
+
+class RuntimeExceptions extends Gatherer {
+  constructor() {
+    super();
+    this._exceptions = [];
+    this._onRuntimeExceptionThrown = this.onRuntimeExceptionThrown.bind(this);
+  }
+
+  onRuntimeExceptionThrown(entry) {
+    this._exceptions.push(entry);
+  }
+
+  beforePass(options) {
+    const driver = options.driver;
+    driver.on('Runtime.exceptionThrown', this._onRuntimeExceptionThrown);
+  }
+
+  afterPass(options) {
+    return Promise.resolve()
+      .then(_ => options.driver.off('Runtime.exceptionThrown', this._onRuntimeExceptionThrown))
+      .then(_ => this._exceptions);
+  }
+}
+
+module.exports = RuntimeExceptions;
diff --git a/lighthouse-core/test/audits/errors-in-console-test.js b/lighthouse-core/test/audits/errors-in-console-test.js
index e17dc35ac723..dfddbb5d24e8 100644
--- a/lighthouse-core/test/audits/errors-in-console-test.js
+++ b/lighthouse-core/test/audits/errors-in-console-test.js
@@ -14,6 +14,7 @@ describe('Console error logs audit', () => {
   it('passes when no console messages were found', () => {
     const auditResult = ErrorLogsAudit.audit({
       ChromeConsoleMessages: [],
+      RuntimeExceptions: [],
     });
     assert.equal(auditResult.rawValue, 0);
     assert.equal(auditResult.score, true);
@@ -32,6 +33,7 @@ describe('Console error logs audit', () => {
           },
         },
       ],
+      RuntimeExceptions: [],
     });
     assert.equal(auditResult.rawValue, 0);
     assert.equal(auditResult.score, true);
@@ -57,10 +59,31 @@ describe('Console error logs audit', () => {
           },
         },
       ],
+      RuntimeExceptions: [{
+        'timestamp': 1506535813608.003,
+        'exceptionDetails': {
+          'url': 'http://example.com/fancybox.js',
+          'stackTrace': {
+            'callFrames': [
+              {
+                'url': 'http://example.com/fancybox.js',
+                'lineNumber': 28,
+                'columnNumber': 20,
+              },
+            ],
+          },
+          'exception': {
+            'className': 'TypeError',
+            'description': 'TypeError: Cannot read property \'msie\' of undefined',
+          },
+          'executionContextId': 3,
+        },
+      }],
     });
-    assert.equal(auditResult.rawValue, 2);
+
+    assert.equal(auditResult.rawValue, 3);
     assert.equal(auditResult.score, false);
-    assert.equal(auditResult.details.items.length, 2);
+    assert.equal(auditResult.details.items.length, 3);
     assert.equal(auditResult.details.items[0][0].type, 'url');
     assert.equal(auditResult.details.items[0][0].text, 'http://www.example.com/favicon.ico');
     assert.equal(auditResult.details.items[0][1].type, 'text');
@@ -71,6 +94,12 @@ describe('Console error logs audit', () => {
     assert.equal(auditResult.details.items[1][1].type, 'text');
     assert.equal(auditResult.details.items[1][1].text,
       'WebSocket connection failed: Unexpected response code: 500');
+    assert.equal(auditResult.details.items[2][0].type, 'url');
+    assert.equal(auditResult.details.items[2][0].text,
+      'http://example.com/fancybox.js');
+    assert.equal(auditResult.details.items[2][1].type, 'text');
+    assert.equal(auditResult.details.items[2][1].text,
+      'TypeError: Cannot read property \'msie\' of undefined');
   });
 
   it('handle the case when some logs fields are undefined', () => {
@@ -82,6 +111,7 @@ describe('Console error logs audit', () => {
           },
         },
       ],
+      RuntimeExceptions: [],
     });
     assert.equal(auditResult.rawValue, 1);
     assert.equal(auditResult.score, false);
diff --git a/lighthouse-core/test/gather/gatherers/runtime-exceptions-test.js b/lighthouse-core/test/gather/gatherers/runtime-exceptions-test.js
new file mode 100644
index 000000000000..ba92870e3a64
--- /dev/null
+++ b/lighthouse-core/test/gather/gatherers/runtime-exceptions-test.js
@@ -0,0 +1,72 @@
+/**
+* @license Copyright 2017 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 RuntimeExceptionsGatherer = require('../../../gather/gatherers/runtime-exceptions');
+const assert = require('assert');
+
+const mockDriver = {
+  off() {},
+};
+
+const wrapSendCommand = (mockDriver, runtimeEx) => {
+  mockDriver = Object.assign({}, mockDriver);
+
+  mockDriver.on = (name, cb) => {
+    if (name === 'Runtime.exceptionThrown') {
+      cb(runtimeEx);
+    }
+  };
+
+  mockDriver.sendCommand = () => {
+    return Promise.resolve();
+  };
+
+  return mockDriver;
+};
+
+describe('RuntimeExceptions', () => {
+  it('captures the exceptions raised', () => {
+    const runtimeExceptionsGatherer = new RuntimeExceptionsGatherer();
+    const runtimeEx =
+      {
+        'timestamp': 1506535813608.003,
+        'exceptionDetails': {
+          'url': 'http://www.example.com/fancybox.js',
+          'stackTrace': {
+            'callFrames': [
+              {
+                'url': 'http://www.example.com/fancybox.js',
+                'lineNumber': 28,
+                'columnNumber': 20,
+              },
+            ],
+          },
+          'exception': {
+            'className': 'TypeError',
+            'description': 'TypeError: Cannot read property \'msie\' of undefined',
+          },
+          'executionContextId': 3,
+        },
+      };
+
+    const options = {
+      driver: wrapSendCommand(mockDriver, runtimeEx),
+    };
+
+    return Promise.resolve(
+      runtimeExceptionsGatherer.beforePass(options))
+      .then(_ => runtimeExceptionsGatherer.afterPass(options))
+      .then((artifact) => {
+        assert.equal(artifact[0].exceptionDetails.exception.description,
+          `TypeError: Cannot read property 'msie' of undefined`);
+        assert.equal(artifact[0].exceptionDetails.url,
+          'http://www.example.com/fancybox.js');
+      });
+  });
+});