Now we keep a collection to determine if a script needs to be added, removed or changed on the client

src/chrome/chromeDebugAdapter.ts

@@ -156,6 +156,8 @@ export abstract class ChromeDebugAdapter implements IDebugAdapter {
 
     public readonly events: StepProgressEventsEmitter;
 
+    private _loadedSourcesByScriptId = new Map<Crdp.Runtime.ScriptId, CrdpScript>();
+
     public constructor({ chromeConnection, lineColTransformer, sourceMapTransformer, pathTransformer, targetFilter, enableSourceMapCaching }: IChromeDebugAdapterOpts,
         session: ChromeDebugSession) {
         telemetry.setupEventHandler(e => session.sendEvent(e));
@@ -603,8 +605,7 @@ export abstract class ChromeDebugAdapter implements IDebugAdapter {
         this.clearTargetContext();
         return this.doAfterProcessingSourceEvents(async () => { // This will not execute until all the on-flight 'new' source events have been processed
             for (let scriptedParseEvent of cachedScriptParsedEvents) {
-                const scriptEvent = await this.scriptToLoadedSourceEvent('removed', scriptedParseEvent);
-                this._session.sendEvent(scriptEvent);
+                this.sendLoadedSourceEvent(scriptedParseEvent, 'removed');
             }
         });
     }
@@ -856,7 +857,28 @@ export abstract class ChromeDebugAdapter implements IDebugAdapter {
     }
 
     protected async sendLoadedSourceEvent(script: Crdp.Debugger.ScriptParsedEvent, loadedSourceEventReason: LoadedSourceEventReason = 'new'): Promise<void> {
+        switch (loadedSourceEventReason) {
+            case 'new':
+            case 'changed':
+                if (this._loadedSourcesByScriptId.get(script.scriptId)) {
+                    loadedSourceEventReason = 'changed';
+                } else {
+                    loadedSourceEventReason = 'new';
+                }
+                this._loadedSourcesByScriptId.set(script.scriptId, script);
+                break;
+            case 'removed':
+                if (!this._loadedSourcesByScriptId.delete(script.scriptId)) {
+                    telemetry.reportEvent('LoadedSourceEventError', { issue: 'Tried to remove non-existent script', scriptId: script.scriptId });
+                    return;
+                }
+                break;
+            default:
+                telemetry.reportEvent('LoadedSourceEventError', { issue: 'Unknown reason', reason: loadedSourceEventReason });
+        }
+
         const scriptEvent = await this.scriptToLoadedSourceEvent(loadedSourceEventReason, script);
+
         this._session.sendEvent(scriptEvent);
     }
 

test/chrome/chromeDebugAdapter.test.ts

@@ -24,7 +24,7 @@ import * as testUtils from '../testUtils';
 import * as utils from '../../src/utils';
 
 /** Not mocked - use for type only */
-import {ChromeDebugAdapter as _ChromeDebugAdapter, LoadedSourceEventReason } from '../../src/chrome/chromeDebugAdapter';
+import {ChromeDebugAdapter as _ChromeDebugAdapter } from '../../src/chrome/chromeDebugAdapter';
 import { InitializedEvent, LoadedSourceEvent, Source, BreakpointEvent } from 'vscode-debugadapter/lib/debugSession';
 
 const MODULE_UNDER_TEST = '../../src/chrome/chromeDebugAdapter';
@@ -559,17 +559,29 @@ suite('ChromeDebugAdapter', () => {
             });
         });
 
-        // This is needed for Edge debug adapter, please keep the signature and logic of sendLoadedSourceEvent() method intact.
-        test('tests that sendLoadedSourceEvent can accept an additional paramter to override the `reason` parameter', () => {
-            const loadedSourceEventReason: LoadedSourceEventReason = 'changed';
+        // This is needed for Edge debug adapter, please keep the logic of sendLoadedSourceEvent()
+        test('tests that sendLoadedSourceEvent will set the `reason` parameter based on our internal view of the events we sent to the client', () => {
+            let eventIndex = 0;
             sendEventHandler = (event) => {
-                assert.equal('loadedSource', event.event);
-                assert.notEqual(null, event.body);
-                assert.equal(loadedSourceEventReason, event.body.reason);
+                switch (eventIndex) {
+                    case 0:
+                        assert.equal('loadedSource', event.event);
+                        assert.notEqual(null, event.body);
+                        assert.equal('new', event.body.reason);
+                        break;
+                    case 1:
+                        assert.equal('loadedSource', event.event);
+                        assert.notEqual(null, event.body);
+                        assert.equal('changed', event.body.reason);
+                        break;
+                    default:
+                        throw new RangeError('Unexpected event index');
+                }
+                ++eventIndex;
             };
 
-            return chromeDebugAdapter.attach(ATTACH_ARGS).then(() => {
-                return (<any>chromeDebugAdapter).sendLoadedSourceEvent({
+            return chromeDebugAdapter.attach(ATTACH_ARGS).then(async () => {
+                await (<any>chromeDebugAdapter).sendLoadedSourceEvent({
                     scriptId: 1,
                     url: '',
                     startLine: 0,
@@ -578,7 +590,17 @@ suite('ChromeDebugAdapter', () => {
                     endColumn: 0,
                     executionContextId: 0,
                     hash: ''
-                }, loadedSourceEventReason);
+                });
+                await (<any>chromeDebugAdapter).sendLoadedSourceEvent({
+                    scriptId: 1,
+                    url: '',
+                    startLine: 0,
+                    startColumn: 0,
+                    endLine: 0,
+                    endColumn: 0,
+                    executionContextId: 0,
+                    hash: ''
+                });
             });
         });