fix: handle parcel shutdown race condition (#834)

Author: jonathanlab

apps/twig/src/main/services/file-watcher/service.ts

@@ -3,9 +3,11 @@ import fs from "node:fs/promises";
 import path from "node:path";
 import * as watcher from "@parcel/watcher";
 import { app } from "electron";
-import { injectable, preDestroy } from "inversify";
+import { inject, injectable, preDestroy } from "inversify";
+import { MAIN_TOKENS } from "../../di/tokens.js";
 import { logger } from "../../lib/logger.js";
 import { TypedEventEmitter } from "../../lib/typed-event-emitter.js";
+import type { ProcessTrackingService } from "../process-tracking/service.js";
 import {
   type DirectoryEntry,
   FileWatcherEvent,
@@ -35,6 +37,13 @@ interface RepoWatcher {
 export class FileWatcherService extends TypedEventEmitter<FileWatcherEvents> {
   private watchers = new Map<string, RepoWatcher>();
 
+  constructor(
+    @inject(MAIN_TOKENS.ProcessTrackingService)
+    private processTracking: ProcessTrackingService,
+  ) {
+    super();
+  }
+
   async listDirectory(dirPath: string): Promise<DirectoryEntry[]> {
     try {
       const entries = await fs.readdir(dirPath, { withFileTypes: true });
@@ -144,6 +153,7 @@ export class FileWatcherService extends TypedEventEmitter<FileWatcherEvents> {
     return watcher.subscribe(
       repoPath,
       (err, events) => {
+        if (this.processTracking.isShuttingDown) return;
         if (err) {
           this.handleWatcherError(err, repoPath);
           return;
@@ -221,6 +231,7 @@ export class FileWatcherService extends TypedEventEmitter<FileWatcherEvents> {
     try {
       const gitDir = await this.resolveGitDir(repoPath);
       return watcher.subscribe(gitDir, (err, events) => {
+        if (this.processTracking.isShuttingDown) return;
         if (err) {
           log.error("Git watcher error:", err);
           return;

apps/twig/src/main/services/focus/service.ts

@@ -15,10 +15,12 @@ import {
   StashPopSaga,
   StashPushSaga,
 } from "@twig/git/sagas/stash";
-import { injectable, preDestroy } from "inversify";
+import { inject, injectable, preDestroy } from "inversify";
+import { MAIN_TOKENS } from "../../di/tokens.js";
 import { logger } from "../../lib/logger";
 import { TypedEventEmitter } from "../../lib/typed-event-emitter";
 import { type FocusSession, focusStore } from "../../utils/store.js";
+import type { ProcessTrackingService } from "../process-tracking/service.js";
 import { getWorktreeLocation } from "../settingsStore";
 import type { FocusResult, StashResult } from "./schemas.js";
 
@@ -49,6 +51,13 @@ export class FocusService extends TypedEventEmitter<FocusServiceEvents> {
   private mainRepoWatcher: watcher.AsyncSubscription | null = null;
   private watchedMainRepo: string | null = null;
 
+  constructor(
+    @inject(MAIN_TOKENS.ProcessTrackingService)
+    private processTracking: ProcessTrackingService,
+  ) {
+    super();
+  }
+
   async startWatchingMainRepo(mainRepoPath: string): Promise<void> {
     if (this.watchedMainRepo === mainRepoPath && this.mainRepoWatcher) {
       return;
@@ -61,6 +70,10 @@ export class FocusService extends TypedEventEmitter<FocusServiceEvents> {
 
     this.watchedMainRepo = mainRepoPath;
     this.mainRepoWatcher = await watcher.subscribe(gitDir, (err, events) => {
+      if (this.processTracking.isShuttingDown) {
+        return;
+      }
+
       if (err) {
         log.error("Main repo watcher error:", err);
         return;

apps/twig/src/main/services/focus/sync-service.ts

@@ -8,8 +8,10 @@ import {
 } from "@twig/git/queries";
 import { ApplyPatchSaga } from "@twig/git/sagas/patch";
 import ignore, { type Ignore } from "ignore";
-import { injectable, preDestroy } from "inversify";
+import { inject, injectable, preDestroy } from "inversify";
+import { MAIN_TOKENS } from "../../di/tokens.js";
 import { logger } from "../../lib/logger.js";
+import type { ProcessTrackingService } from "../process-tracking/service.js";
 
 const log = logger.scope("focus-sync");
 
@@ -46,6 +48,11 @@ export class FocusSyncService {
   /** Files we recently wrote - map of absolute path to write timestamp */
   private recentWrites: Map<string, number> = new Map();
 
+  constructor(
+    @inject(MAIN_TOKENS.ProcessTrackingService)
+    private processTracking: ProcessTrackingService,
+  ) {}
+
   async startSync(mainRepoPath: string, worktreePath: string): Promise<void> {
     const [mainExists, worktreeExists] = await Promise.all([
       fs
@@ -99,6 +106,7 @@ export class FocusSyncService {
       const mainSubPromise = watcher.subscribe(
         mainRepoPath,
         (err, events) => {
+          if (this.processTracking.isShuttingDown) return;
           if (err) {
             log.error("Main repo watcher error:", err);
             return;
@@ -128,6 +136,7 @@ export class FocusSyncService {
       const worktreeSubPromise = watcher.subscribe(
         worktreePath,
         (err, events) => {
+          if (this.processTracking.isShuttingDown) return;
           if (err) {
             log.error("Worktree watcher error:", err);
             return;

apps/twig/src/main/services/process-tracking/service.ts

@@ -34,6 +34,12 @@ export interface ProcessSnapshot {
 
 @injectable()
 export class ProcessTrackingService {
+  private _isShuttingDown = false;
+
+  get isShuttingDown(): boolean {
+    return this._isShuttingDown;
+  }
+
   private processes = new Map<number, TrackedProcess>();
   private taskProcesses = new Map<string, Set<number>>();
 
@@ -235,6 +241,8 @@ export class ProcessTrackingService {
 
   @preDestroy()
   killAll(): void {
+    this._isShuttingDown = true;
+
     const count = this.processes.size;
     if (count > 0) {
       log.info(`Killing all tracked processes (${count} active)`);