Fix app config file watching on Windows

packages/app/src/cli/services/dev/app-events/file-watcher.test.ts

@@ -663,6 +663,64 @@ describe('file-watcher events', () => {
       mockedExtractImportPaths.mockReset()
     })
 
+    test('detects app config changes when chokidar reports backslash paths (Windows)', async () => {
+      // Simulates the Windows scenario where chokidar returns paths with backslashes
+      // but the app configuration stores paths with forward slashes
+      let eventHandler: any
+
+      mockExtensionWatchedFiles(extension1, ['/extensions/ui_extension_1/index.js'])
+      mockExtensionWatchedFiles(extension1B, ['/extensions/ui_extension_1/index.js'])
+      mockExtensionWatchedFiles(extension2, ['/extensions/ui_extension_2/index.js'])
+      mockExtensionWatchedFiles(functionExtension, ['/extensions/my-function/src/index.js'])
+      mockExtensionWatchedFiles(posExtension, [])
+      mockExtensionWatchedFiles(appAccessExtension, [])
+
+      const testApp = {
+        ...defaultApp,
+        allExtensions: defaultApp.allExtensions,
+        nonConfigExtensions: defaultApp.allExtensions.filter((ext) => !ext.isAppConfigExtension),
+        realExtensions: defaultApp.allExtensions,
+      }
+
+      const mockWatcher = {
+        on: vi.fn((event: string, listener: any) => {
+          if (event === 'all') {
+            eventHandler = listener
+          }
+          return mockWatcher
+        }),
+        close: vi.fn(() => Promise.resolve()),
+      }
+      vi.spyOn(chokidar, 'watch').mockReturnValue(mockWatcher as any)
+
+      const fileWatcher = new FileWatcher(testApp, outputOptions, 50)
+      const onChange = vi.fn()
+      fileWatcher.onChange(onChange)
+
+      await fileWatcher.start()
+      await flushPromises()
+
+      // Fire event with backslash path (as chokidar would on Windows)
+      // while app.configuration.path uses forward slashes
+      await eventHandler('change', '\\shopify.app.toml')
+
+      await vi.waitFor(
+        () => {
+          expect(onChange).toHaveBeenCalled()
+          const calls = onChange.mock.calls
+          const actualEvents = calls.find((call) => call[0].length > 0)?.[0]
+
+          if (!actualEvents) {
+            throw new Error('Expected onChange to be called with events, but all calls had empty arrays')
+          }
+
+          expect(actualEvents).toHaveLength(1)
+          expect(actualEvents[0].type).toBe('extensions_config_updated')
+        },
+        {timeout: 1000, interval: 50},
+      )
+    })
+
     test('handles rapid file changes without hanging', async () => {
       let eventHandler: any
       const events: WatcherEvent[] = []

packages/app/src/cli/services/dev/app-events/file-watcher.ts

@@ -230,13 +230,13 @@ export class FileWatcher {
   private readonly handleFileEvent = (event: string, path: string) => {
     const startTime = startHRTime()
     const normalizedPath = normalizePath(path)
-    const isConfigAppPath = path === this.app.configuration.path
+    const isConfigAppPath = normalizedPath === normalizePath(this.app.configuration.path)
     const isExtensionToml = path.endsWith('.extension.toml')
 
     outputDebug(`🌀: ${event} ${path.replace(this.app.directory, '')}\n`)
 
     if (isConfigAppPath) {
-      this.handleEventForExtension(event, path, this.app.directory, startTime, false)
+      this.handleEventForExtension(event, path, this.app.directory, startTime, false, isExtensionToml, isConfigAppPath)
     } else {
       const affectedExtensions = this.extensionWatchedFiles.get(normalizedPath)
       const isUnknownExtension = affectedExtensions === undefined || affectedExtensions.size === 0
@@ -249,10 +249,10 @@ export class FileWatcher {
       }
 
       for (const extensionPath of affectedExtensions ?? []) {
-        this.handleEventForExtension(event, path, extensionPath, startTime, false)
+        this.handleEventForExtension(event, path, extensionPath, startTime, false, isExtensionToml, isConfigAppPath)
       }
       if (isUnknownExtension) {
-        this.handleEventForExtension(event, path, this.app.directory, startTime, true)
+        this.handleEventForExtension(event, path, this.app.directory, startTime, true, isExtensionToml, isConfigAppPath)
       }
     }
     this.debouncedEmit()
@@ -264,9 +264,9 @@ export class FileWatcher {
     extensionPath: string,
     startTime: StartTime,
     isUnknownExtension: boolean,
+    isExtensionToml: boolean,
+    isConfigAppPath: boolean,
   ) {
-    const isExtensionToml = path.endsWith('.extension.toml')
-    const isConfigAppPath = path === this.app.configuration.path
 
     switch (event) {
       case 'change':