microsoft/vscode-react-native
Publicmirrored fromhttps://github.com/microsoft/vscode-react-nativeAvailable
src/debugger/forkedAppWorker.ts
102lines · modecode
| 1 | // Copyright (c) Microsoft Corporation. All rights reserved. |
| 2 | // Licensed under the MIT license. See LICENSE file in the project root for details. |
| 3 | |
| 4 | import * as Q from "q"; |
| 5 | import * as path from "path"; |
| 6 | import * as child_process from "child_process"; |
| 7 | import {ScriptImporter} from "./scriptImporter"; |
| 8 | |
| 9 | import { Log } from "../common/log/log"; |
| 10 | import { LogLevel } from "../common/log/logHelper"; |
| 11 | import { ErrorHelper } from "../common/error/errorHelper"; |
| 12 | import { IDebuggeeWorker, RNAppMessage } from "./appWorker"; |
| 13 | |
| 14 | function printDebuggingError(message: string, reason: any) { |
| 15 | Log.logWarning(ErrorHelper.getNestedWarning(reason, `${message}. Debugging won't work: Try reloading the JS from inside the app, or Reconnect the VS Code debugger`)); |
| 16 | } |
| 17 | |
| 18 | /** This class will run the RN App logic inside a forked Node process. The framework to run the logic is provided by the file |
| 19 | * debuggerWorker.js (designed to run on a WebWorker). We add a couple of tweaks (mostly to polyfill WebWorker API) to that |
| 20 | * file and load it inside of a process. |
| 21 | * On this side we listen to IPC messages and either respond to them or redirect them to packager via MultipleLifetimeAppWorker's |
| 22 | * instance. We also intercept packager's signal to load the bundle's code and mutate the message with path to file we've downloaded |
| 23 | * to let importScripts function take this file. |
| 24 | */ |
| 25 | export class ForkedAppWorker implements IDebuggeeWorker { |
| 26 | |
| 27 | private scriptImporter: ScriptImporter; |
| 28 | private debuggeeProcess: child_process.ChildProcess = null; |
| 29 | /** A deferred that we use to make sure that worker has been loaded completely defore start sending IPC messages */ |
| 30 | private workerLoaded = Q.defer<void>(); |
| 31 | |
| 32 | constructor( |
| 33 | private packagerPort: number, |
| 34 | private sourcesStoragePath: string, |
| 35 | private postReplyToApp: (message: any) => void |
| 36 | ) { |
| 37 | this.scriptImporter = new ScriptImporter(packagerPort, sourcesStoragePath); |
| 38 | } |
| 39 | |
| 40 | public stop() { |
| 41 | if (this.debuggeeProcess) { |
| 42 | Log.logInternalMessage(LogLevel.Info, `About to kill debuggee with pid ${this.debuggeeProcess.pid}`); |
| 43 | this.debuggeeProcess.kill(); |
| 44 | this.debuggeeProcess = null; |
| 45 | } |
| 46 | } |
| 47 | |
| 48 | public start(): Q.Promise<number> { |
| 49 | let scriptToRunPath = path.resolve(this.sourcesStoragePath, ScriptImporter.DEBUGGER_WORKER_FILENAME); |
| 50 | const port = Math.round(Math.random() * 40000 + 3000); |
| 51 | |
| 52 | // Note that we set --debug-brk flag to pause the process on the first line - this is |
| 53 | // required for debug adapter to set the breakpoints BEFORE the debuggee has started. |
| 54 | // The adapter will continue execution once it's done with breakpoints. |
| 55 | const nodeArgs = [`--inspect=${port}`, "--debug-brk", scriptToRunPath]; |
| 56 | // Start child Node process in debugging mode |
| 57 | this.debuggeeProcess = child_process.spawn("node", nodeArgs, { |
| 58 | stdio: ["pipe", "pipe", "pipe", "ipc"], |
| 59 | }) |
| 60 | .on("message", (message: any) => { |
| 61 | // 'workerLoaded' is a special message that indicates that worker is done with loading. |
| 62 | // We need to wait for it before doing any IPC because process.send doesn't seems to care |
| 63 | // about whether the messahe has been received or not and the first messages are often get |
| 64 | // discarded by spawned process |
| 65 | if (message && message.workerLoaded) { |
| 66 | this.workerLoaded.resolve(void 0); |
| 67 | return; |
| 68 | } |
| 69 | |
| 70 | this.postReplyToApp(message); |
| 71 | }) |
| 72 | .on("error", (error: Error) => { |
| 73 | Log.logWarning(error); |
| 74 | }); |
| 75 | |
| 76 | // Resolve with port debugger server is listening on |
| 77 | // This will be sent to subscribers of MLAppWorker in "connected" event |
| 78 | Log.logInternalMessage(LogLevel.Info, |
| 79 | `Spawned debuggee process with pid ${this.debuggeeProcess.pid} listening to ${port}`); |
| 80 | |
| 81 | return Q.resolve(port); |
| 82 | } |
| 83 | |
| 84 | public postMessage(rnMessage: RNAppMessage): void { |
| 85 | // Before sending messages, make sure that the worker is loaded |
| 86 | this.workerLoaded.promise |
| 87 | .then(() => { |
| 88 | if (rnMessage.method !== "executeApplicationScript") return Q.resolve(rnMessage); |
| 89 | |
| 90 | // When packager asks worker to load bundle we download that bundle and |
| 91 | // then set url field to point to that downloaded bundle, so the worker |
| 92 | // will take our modified bundle |
| 93 | Log.logInternalMessage(LogLevel.Info, "Packager requested runtime to load script from " + rnMessage.url); |
| 94 | return this.scriptImporter.downloadAppScript(rnMessage.url) |
| 95 | .then(downloadedScript => { |
| 96 | return Object.assign({}, rnMessage, { url: downloadedScript.filepath }); |
| 97 | }); |
| 98 | }) |
| 99 | .done((message: RNAppMessage) => this.debuggeeProcess.send({ data: message }), |
| 100 | reason => printDebuggingError(`Couldn't import script at <${rnMessage.url}>`, reason)); |
| 101 | } |
| 102 | } |
| 103 | |