Appium log hangs forever when it gets to `Executing Flutter driver command 'click'`

Appium log hangs forever when it gets to Executing Flutter driver command 'click'.

The app launches fine. Then the last two lines I see are:

[debug] [FlutterDriver] Executing Flutter driver command 'click' [debug] [FlutterDriver] >>> {"command":"tap","finderType":"ByValueKey","keyValueString":"contact-button","keyValueType":"String"}

Below is the appium log from the point where flutter driver is first mentioned. I could post the entire log.

Does this mean…

• the element cannot be found?
• there’s something wrong with the setup?
• something else?

At the moment, I am quite clueless as to how to troubleshoot this.

[debug] [FlutterDriver] /Users/liamharris/Library/Android/sdk/platform-tools/adb -s emulator-5554 forward tcp:46427 tcp:46427
[FlutterDriver] Attempt #1
[FlutterDriver] Connecting to Dart Observatory: ws://127.0.0.1:46427/gY6q1iZE0u8=/ws
[FlutterDriver] Connected to ws://127.0.0.1:46427/gY6q1iZE0u8=/ws
[FlutterDriver] Listing all isolates: [{"type":"@Isolate","id":"isolates/1851195815643283","name":"main","number":"1851195815643283","isSystemIsolate":false}]
[FlutterDriver] "ext.flutter.driver" is not found in "extensionRPCs" ["ext.ui.window.scheduleFrame","ext.dart.io.getHttpEnableTimelineLogging","ext.dart.io.setHttpEnableTimelineLogging","ext.dart.io.httpEnableTimelineLogging","ext.dart.io.getSocketProfile","ext.dart.io.startSocketProfiling","ext.dart.io.pauseSocketProfiling","ext.dart.io.socketProfilingEnabled","ext.dart.io.clearSocketProfile","ext.dart.io.getVersion","ext.dart.io.getHttpProfile","ext.dart.io.getHttpProfileRequest","ext.dart.io.clearHttpProfile","ext.flutter.reassemble","ext.flutter.exit","ext.flutter.platformOverride","ext.flutter.brightnessOverride","ext.flutter.connectedVmServiceUri","ext.flutter.activeDevToolsServerAddress","ext.flutter.timeDilation","ext.flutter.evict","ext.flutter.invertOversizedImages","ext.flutter.debugPaint","ext.flutter.debugPaintBaselinesEnabled","ext.flutter.repaintRainbow","ext.flutter.debugCheckElevationsEnabled","ext.flutter.debugDumpLayerTree","ext.flutter.debugDumpRenderTree","ext.flutter.debugDumpSemanticsTreeInTraversalOrder","ext.flutter.debugDumpSemanticsTreeInInverseHitTestOrder","ext.flutter.debugDumpApp","ext.flutter.showPerformanceOverlay","ext.flutter.didSendFirstFrameEvent","ext.flutter.didSendFirstFrameRasterizedEvent","ext.flutter.fastReassemble","ext.flutter.profileWidgetBuilds","ext.flutter.debugAllowBanner","ext.flutter.debugWidgetInspector"]
[FlutterDriver] Waiting 300 seconds before trying...
[FlutterDriver] Attempt #2
[FlutterDriver] Connecting to Dart Observatory: ws://127.0.0.1:46427/gY6q1iZE0u8=/ws
[FlutterDriver] Connected to ws://127.0.0.1:46427/gY6q1iZE0u8=/ws
[FlutterDriver] Listing all isolates: [{"type":"@Isolate","id":"isolates/1851195815643283","name":"main","number":"1851195815643283","isSystemIsolate":false}]
[Appium] New FlutterDriver session created successfully, session e57475b6-a658-4457-bb90-03aa62bed580 added to master session list
[debug] [BaseDriver] Event 'newSessionStarted' logged at 1630690650505 (19:37:30 GMT+0200 (Central European Summer Time))
[debug] [MJSONWP (e57475b6)] Cached the protocol value 'MJSONWP' for the new session e57475b6-a658-4457-bb90-03aa62bed580
[debug] [MJSONWP (e57475b6)] Responding to client with driver.createSession() result: {"shell":false,"allowCors":false,"reboot":false,"ipa":null,"address":"0.0.0.0","port":4723,"basePath":"/wd/hub","keepAliveTimeout":null,"callbackAddress":null,"callbackPort":null,"bootstrapPort":4724,"backendRetries":3,"sessionOverride":false,"launch":false,"logFile":null,"loglevel":"debug","logTimestamp":false,"localTimezone":false,"logNoColors":false,"webhook":null,"safari":false,"defaultDevice":false,"forceIphone":false,"forceIpad":false,"automationTraceTemplatePath":null,"instrumentsPath":null,"nodeconfig":null,"robotAddress":"0.0.0.0","robotPort":-1,"chromedriverExecutable":null,"showConfig":false,"noPermsCheck":false,"enforceStrictCaps":false,"isolateSimDevice":false,"tmpDir":"/var/folders/nm/1rsxlpr13h99w167fps7q95m0000gn/T","traceDir":null,"debugLogSpacing":false,"suppressKillServer":false,"longStacktrace":false,"webkitDebugProxyPort":27753,"wdaLocalPort":8100,"defaultCapabilities":{},"relaxedSecurityEnabled":false,"allowInsecure":[],"denyInsecure":[],"defaultCommandTimeout":60,"keepArtifacts":fals...
[HTTP] <-- POST /wd/hub/session 200 321680 ms - 2121
[HTTP] 
[HTTP] --> POST /wd/hub/session/e57475b6-a658-4457-bb90-03aa62bed580/element/eyJmaW5kZXJUeXBlIjoiQnlWYWx1ZUtleSIsImtleVZhbHVlU3RyaW5nIjoiY29udGFjdC1idXR0b24iLCJrZXlWYWx1ZVR5cGUiOiJTdHJpbmcifQ==/click
[HTTP] {"id":"eyJmaW5kZXJUeXBlIjoiQnlWYWx1ZUtleSIsImtleVZhbHVlU3RyaW5nIjoiY29udGFjdC1idXR0b24iLCJrZXlWYWx1ZVR5cGUiOiJTdHJpbmcifQ==","sessionId":"e57475b6-a658-4457-bb90-03aa62bed580"}
[debug] [MJSONWP (e57475b6)] Calling AppiumDriver.click() with args: ["eyJmaW5kZXJUeXBlIjoiQnlWYWx1ZUtleSIsImtleVZhbHVlU3RyaW5nIjoiY29udGFjdC1idXR0b24iLCJrZXlWYWx1ZVR5cGUiOiJTdHJpbmcifQ==","e57475b6-a658-4457-bb90-03aa62bed580"]
[debug] [FlutterDriver] Executing Flutter driver command 'click'
[debug] [FlutterDriver] >>> {"command":"tap","finderType":"ByValueKey","keyValueString":"contact-button","keyValueType":"String"}

[arctouch-thiagowerner]

I solved this problem and identified the root cause.

By default, Flutter Driver waits until there is no pending frame scheduled in the app under test before executing an action. Because of this, some interactions such as click() may not work properly. To counter it, we use setFrameSync() function before and after the desired action.

So with that, the code would be:

    def tap_element(self, element: Element):
        self.driver.execute_script('flutter:setFrameSync', True, 5000)
        self.find(element).click()
        self.driver.execute_script('flutter:setFrameSync', False, 5000)

[KazuCocoa]

This behavior seems to be coming inside DartVM/Flutter. Close as not in this driver itself.