feat: add support for debug with hmr

Add support for Debug + HMR - currently it is not working, as when a hot-module is applied, VSCode does not know that the current hot-module is mapped to the actual changed file (main-view-model) for example.
To fix this, add SourceMapTransformer and plug in the scriptParsed method. When breakpoint is set, cache it (in nativeScriptDebugAdapter), so once hot-module is applied, set the breakpoints from its original file (i.e. main-view-model) in the newly applied hot module.
This is exactly how Chrome works.

Also, add logic in pathTransformer to map files from `platforms` dir when debugging on iOS.

Author: rosen-vladimirov

Diff for: package.json

@@ -29,7 +29,7 @@
     "semver": "5.6.0",
     "universal-analytics": "0.4.15",
     "uuid": "3.3.2",
-    "vscode-chrome-debug-core": "6.7.45",
+    "vscode-chrome-debug-core": "6.7.46",
     "vscode-debugadapter": "1.34.0"
   },
   "devDependencies": {

Diff for: src/debug-adapter/nativeScriptDebug.ts

@@ -3,6 +3,7 @@ import * as path from 'path';
 import { chromeConnection, ChromeDebugSession } from 'vscode-chrome-debug-core';
 import { NativeScriptDebugAdapter } from './nativeScriptDebugAdapter';
 import { NativeScriptPathTransformer } from './nativeScriptPathTransformer';
+import { NativeScriptSourceMapTransformer } from './nativeScriptSourceMapTransformer';
 import { NativeScriptTargetDiscovery } from './nativeScriptTargetDiscovery';
 
 class NSAndroidConnection extends chromeConnection.ChromeConnection {
@@ -18,4 +19,5 @@ ChromeDebugSession.run(ChromeDebugSession.getSession(
         extensionName: 'nativescript-extension',
         logFilePath: path.join(os.tmpdir(), 'nativescript-extension.txt'),
         pathTransformer: NativeScriptPathTransformer,
+        sourceMapTransformer: NativeScriptSourceMapTransformer,
     }));

Diff for: src/debug-adapter/nativeScriptDebugAdapter.ts

@@ -1,9 +1,17 @@
 import { existsSync, readFileSync } from 'fs';
+import * as _ from 'lodash';
 import { join } from 'path';
-import { ChromeDebugAdapter, IRestartRequestArgs } from 'vscode-chrome-debug-core';
+import {
+    ChromeDebugAdapter,
+    IRestartRequestArgs,
+    ISetBreakpointsArgs,
+    ISetBreakpointsResponseBody,
+    ITelemetryPropertyCollector,
+} from 'vscode-chrome-debug-core';
 import { Event, TerminatedEvent } from 'vscode-debugadapter';
 import { DebugProtocol } from 'vscode-debugprotocol';
 import * as extProtocol from '../common/extensionProtocol';
+import { NativeScriptSourceMapTransformer } from './nativeScriptSourceMapTransformer';
 
 const reconnectAfterLiveSyncTimeout = 10 * 1000;
 
@@ -14,6 +22,7 @@ export class NativeScriptDebugAdapter extends ChromeDebugAdapter {
     private portWaitingResolve: any;
     private isDisconnecting: boolean = false;
     private isLiveSyncRestart: boolean = false;
+    private breakPointsCache: { [file: string]: { args: ISetBreakpointsArgs, requestSeq: number, ids: number[] } } = {};
 
     public attach(args: any): Promise<void> {
         return this.processRequestAndAttach(args);
@@ -41,6 +50,27 @@ export class NativeScriptDebugAdapter extends ChromeDebugAdapter {
         super.disconnect(args);
     }
 
+    public async setCachedBreakpointsForScript(script: string): Promise<void> {
+        const breakPointData = this.breakPointsCache[script];
+
+        if (breakPointData) {
+            await this.setBreakpoints(breakPointData.args, null, breakPointData.requestSeq, breakPointData.ids);
+        }
+    }
+
+    public async setBreakpoints(
+        args: ISetBreakpointsArgs,
+        telemetryPropertyCollector: ITelemetryPropertyCollector,
+        requestSeq: number,
+        ids?: number[]): Promise<ISetBreakpointsResponseBody> {
+
+        if (args && args.source && args.source.path) {
+            this.breakPointsCache[args.source.path] = { args: _.cloneDeep(args), requestSeq, ids };
+        }
+
+        return super.setBreakpoints(args, telemetryPropertyCollector, requestSeq, ids);
+    }
+
     protected async terminateSession(reason: string, disconnectArgs?: DebugProtocol.DisconnectArguments, restart?: IRestartRequestArgs): Promise<void> {
         let restartRequestArgs = restart;
         let timeoutId;
@@ -113,6 +143,7 @@ export class NativeScriptDebugAdapter extends ChromeDebugAdapter {
         const appDirPath = this.getAppDirPath(transformedArgs.webRoot);
 
         (this.pathTransformer as any).setTransformOptions(args.platform, appDirPath, transformedArgs.webRoot);
+        (this.sourceMapTransformer as NativeScriptSourceMapTransformer).setDebugAdapter(this);
         (ChromeDebugAdapter as any).SET_BREAKPOINTS_TIMEOUT = 20000;
 
         this.isLiveSync = args.watch;
@@ -145,7 +176,7 @@ export class NativeScriptDebugAdapter extends ChromeDebugAdapter {
         }
 
         if (!args.sourceMapPathOverrides) {
-            args.sourceMapPathOverrides = { };
+            args.sourceMapPathOverrides = {};
         }
 
         if (!args.sourceMapPathOverrides['webpack:///*']) {

Diff for: src/debug-adapter/nativeScriptPathTransformer.ts

@@ -25,13 +25,14 @@ export class NativeScriptPathTransformer extends UrlPathTransformer {
         }
 
         const isAndroid = this.targetPlatform === 'android';
+        const isIOS = this.targetPlatform === 'ios';
 
         if (_.startsWith(scriptUrl, 'mdha:')) {
             scriptUrl = _.trimStart(scriptUrl, 'mdha:');
         }
 
         if (path.isAbsolute(scriptUrl) && fs.existsSync(scriptUrl)) {
-            return Promise.resolve(scriptUrl);
+            return scriptUrl;
         }
 
         const filePattern = this.filePatterns[this.targetPlatform];
@@ -56,20 +57,23 @@ export class NativeScriptPathTransformer extends UrlPathTransformer {
         let platformSpecificPath = this.getPlatformSpecificPath(absolutePath);
 
         if (platformSpecificPath) {
-            return Promise.resolve(platformSpecificPath);
+            return platformSpecificPath;
         }
 
         if (isAndroid) {
             // handle files like /data/data/internal/ts_helpers.ts
             absolutePath = path.resolve(path.join(this.webRoot, 'platforms', this.targetPlatform.toLowerCase(), 'app', 'src', 'main', 'assets', relativePath));
-            platformSpecificPath = this.getPlatformSpecificPath(absolutePath);
+        } else if (isIOS) {
+            absolutePath = path.resolve(path.join(this.webRoot, 'platforms', this.targetPlatform.toLowerCase(), this.getAppName(this.webRoot), relativePath));
+        }
 
-            if (platformSpecificPath) {
-                return Promise.resolve(platformSpecificPath);
-            }
+        platformSpecificPath = this.getPlatformSpecificPath(absolutePath);
+
+        if (platformSpecificPath) {
+            return platformSpecificPath;
         }
 
-        return Promise.resolve(scriptUrl);
+        return scriptUrl;
     }
 
     private getPlatformSpecificPath(rawPath: string): string {
@@ -89,4 +93,8 @@ export class NativeScriptPathTransformer extends UrlPathTransformer {
 
         return null;
     }
+
+    private getAppName(projectDir: string): string {
+        return _.filter(projectDir.split(''), (c) => /[a-zA-Z0-9]/.test(c)).join('');
+    }
 }

Diff for: src/debug-adapter/nativeScriptSourceMapTransformer.ts

@@ -0,0 +1,26 @@
+import { BaseSourceMapTransformer } from 'vscode-chrome-debug-core';
+import { NativeScriptDebugAdapter } from './nativeScriptDebugAdapter';
+
+export class NativeScriptSourceMapTransformer extends BaseSourceMapTransformer {
+    private debugAdapter: NativeScriptDebugAdapter;
+
+    constructor(sourceHandles: any) {
+        super(sourceHandles);
+    }
+
+    public setDebugAdapter(debugAdapter: NativeScriptDebugAdapter): void {
+        this.debugAdapter = debugAdapter;
+    }
+
+    public async scriptParsed(pathToGenerated: string, sourceMapURL: string): Promise<string[]> {
+        const scriptParsedResult = await super.scriptParsed(pathToGenerated, sourceMapURL);
+
+        if (scriptParsedResult && scriptParsedResult.length) {
+            for (const script of scriptParsedResult) {
+                await this.debugAdapter.setCachedBreakpointsForScript(script);
+            }
+        }
+
+        return scriptParsedResult;
+    }
+}

Diff for: src/main.ts

@@ -110,8 +110,8 @@ export function activate(context: vscode.ExtensionContext) {
             const method = service[request.method];
             const response = typeof method === 'function' ? service[request.method].call(service, ...request.args) : method;
 
-            if (response.then) {
-                response.then((result) => event.session.customRequest('onExtensionResponse', { requestId: request.id, result }),
+            if (response && response.then) {
+                response.then((result) => event.session && event.session.customRequest('onExtensionResponse', { requestId: request.id, result }),
                     (err: Error) => {
                         vscode.window.showErrorMessage(err.message);
                         event.session.customRequest('onExtensionResponse', { requestId: request.id, isError: true, message: err.message });

Diff for: src/tests/nativeScriptDebugAdapter.tests.ts

@@ -22,7 +22,7 @@ const defaultArgsMock: any = {
     platform: 'android',
     request: 'attach',
     stopOnEntry: true,
-    tnsArgs: [ 'mockArgs'],
+    tnsArgs: ['mockArgs'],
     watch: true,
 };
 
@@ -37,6 +37,7 @@ describe('NativeScriptDebugAdapter', () => {
     let chromeSessionMock: any;
     let chromeConnectionMock: any;
     let pathTransformerMock: any;
+    let sourceMapTransformer: any;
 
     beforeEach(() => {
         chromeSessionMock = {
@@ -61,16 +62,24 @@ describe('NativeScriptDebugAdapter', () => {
             setTransformOptions: () => ({}),
         };
 
-        nativeScriptDebugAdapter = new NativeScriptDebugAdapter(
-            { chromeConnection: mockConstructor(chromeConnectionMock), pathTransformer: mockConstructor(pathTransformerMock) },
+        sourceMapTransformer = {
+            clearTargetContext: () => undefined,
+            setDebugAdapter: () => undefined,
+        };
+
+        nativeScriptDebugAdapter = new NativeScriptDebugAdapter({
+            chromeConnection: mockConstructor(chromeConnectionMock),
+            pathTransformer: mockConstructor(pathTransformerMock),
+            sourceMapTransformer: mockConstructor(sourceMapTransformer),
+        },
             chromeSessionMock,
         );
 
         ChromeDebugAdapter.prototype.attach = () => Promise.resolve();
     });
 
-    const platforms = [ 'android', 'ios' ];
-    const launchMethods = [ 'launch', 'attach' ];
+    const platforms = ['android', 'ios'];
+    const launchMethods = ['launch', 'attach'];
 
     platforms.forEach((platform) => {
         launchMethods.forEach((method) => {