core(source-maps): use Scripts as a dependency (#15293)

GoogleChrome · Jul 21, 2023 · f60f4e4 · f60f4e4
1 parent 42ffe53
commit f60f4e4
Show file tree

Hide file tree

Showing 3 changed files with 68 additions and 116 deletions.
diff --git a/core/gather/gatherers/scripts.js b/core/gather/gatherers/scripts.js
@@ -48,8 +48,11 @@ function isLighthouseRuntimeEvaluateScript(script) {
  * @fileoverview Gets JavaScript file contents.
  */
 class Scripts extends BaseGatherer {
+  static symbol = Symbol('Scripts');
+
   /** @type {LH.Gatherer.GathererMeta} */
   meta = {
+    symbol: Scripts.symbol,
     supportedModes: ['timespan', 'navigation'],
   };
 
@@ -91,11 +94,6 @@ class Scripts extends BaseGatherer {
 
     session.off('Debugger.scriptParsed', this.onScriptParsed);
 
-    // Without this line the Debugger domain will be off in FR runner,
-    // because only the legacy gatherer has special handling for multiple,
-    // overlapped enabled/disable calls.
-    await session.sendCommand('Debugger.enable');
-
     // If run on a mobile device, be sensitive to memory limitations and only
     // request one at a time.
     this._scriptContents = await runInSeriesOrParallel(

diff --git a/core/gather/gatherers/source-maps.js b/core/gather/gatherers/source-maps.js
@@ -6,23 +6,18 @@
 
 import SDK from '../../lib/cdt/SDK.js';
 import BaseGatherer from '../base-gatherer.js';
+import Scripts from './scripts.js';
 
 /**
  * @fileoverview Gets JavaScript source maps.
  */
 class SourceMaps extends BaseGatherer {
-  /** @type {LH.Gatherer.GathererMeta} */
+  /** @type {LH.Gatherer.GathererMeta<'Scripts'>} */
   meta = {
     supportedModes: ['timespan', 'navigation'],
+    dependencies: {Scripts: Scripts.symbol},
   };
 
-  constructor() {
-    super();
-    /** @type {LH.Crdp.Debugger.ScriptParsedEvent[]} */
-    this._scriptParsedEvents = [];
-    this.onScriptParsed = this.onScriptParsed.bind(this);
-  }
-
   /**
    * @param {LH.Gatherer.Driver} driver
    * @param {string} sourceMapUrl
@@ -45,15 +40,6 @@ class SourceMaps extends BaseGatherer {
     return SDK.SourceMap.parseSourceMap(buffer.toString());
   }
 
-  /**
-   * @param {LH.Crdp.Debugger.ScriptParsedEvent} event
-   */
-  onScriptParsed(event) {
-    if (event.sourceMapURL) {
-      this._scriptParsedEvents.push(event);
-    }
-  }
-
   /**
    * @param {string} url
    * @param {string} base
@@ -69,27 +55,27 @@ class SourceMaps extends BaseGatherer {
 
   /**
    * @param {LH.Gatherer.Driver} driver
-   * @param {LH.Crdp.Debugger.ScriptParsedEvent} event
+   * @param {LH.Artifacts.Script} script
    * @return {Promise<LH.Artifacts.SourceMap>}
    */
-  async _retrieveMapFromScriptParsedEvent(driver, event) {
-    if (!event.sourceMapURL) {
+  async _retrieveMapFromScript(driver, script) {
+    if (!script.sourceMapURL) {
       throw new Error('precondition failed: event.sourceMapURL should exist');
     }
 
     // `sourceMapURL` is simply the URL found in either a magic comment or an x-sourcemap header.
     // It has not been resolved to a base url.
-    const isSourceMapADataUri = event.sourceMapURL.startsWith('data:');
-    const scriptUrl = event.url;
+    const isSourceMapADataUri = script.sourceMapURL.startsWith('data:');
+    const scriptUrl = script.name;
     const rawSourceMapUrl = isSourceMapADataUri ?
-        event.sourceMapURL :
-        this._resolveUrl(event.sourceMapURL, event.url);
+        script.sourceMapURL :
+        this._resolveUrl(script.sourceMapURL, script.name);
 
     if (!rawSourceMapUrl) {
       return {
-        scriptId: event.scriptId,
+        scriptId: script.scriptId,
         scriptUrl,
-        errorMessage: `Could not resolve map url: ${event.sourceMapURL}`,
+        errorMessage: `Could not resolve map url: ${script.sourceMapURL}`,
       };
     }
 
@@ -109,14 +95,14 @@ class SourceMaps extends BaseGatherer {
         map.sections = map.sections.filter(section => section.map);
       }
       return {
-        scriptId: event.scriptId,
+        scriptId: script.scriptId,
         scriptUrl,
         sourceMapUrl,
         map,
       };
     } catch (err) {
       return {
-        scriptId: event.scriptId,
+        scriptId: script.scriptId,
         scriptUrl,
         sourceMapUrl,
         errorMessage: err.toString(),
@@ -125,30 +111,13 @@ class SourceMaps extends BaseGatherer {
   }
 
   /**
-   * @param {LH.Gatherer.Context} context
-   */
-  async startSensitiveInstrumentation(context) {
-    const session = context.driver.defaultSession;
-    session.on('Debugger.scriptParsed', this.onScriptParsed);
-    await session.sendCommand('Debugger.enable');
-  }
-
-  /**
-   * @param {LH.Gatherer.Context} context
-   */
-  async stopSensitiveInstrumentation(context) {
-    const session = context.driver.defaultSession;
-    await session.sendCommand('Debugger.disable');
-    session.off('Debugger.scriptParsed', this.onScriptParsed);
-  }
-
-  /**
-   * @param {LH.Gatherer.Context} context
+   * @param {LH.Gatherer.Context<'Scripts'>} context
    * @return {Promise<LH.Artifacts['SourceMaps']>}
    */
   async getArtifact(context) {
-    const eventProcessPromises = this._scriptParsedEvents
-      .map((event) => this._retrieveMapFromScriptParsedEvent(context.driver, event));
+    const eventProcessPromises = context.dependencies.Scripts
+      .filter(script => script.sourceMapURL)
+      .map(script => this._retrieveMapFromScript(context.driver, script));
     return Promise.all(eventProcessPromises);
   }
 }