Stuck in "Waiting for window's root view controller's view to appear."

[BenBach]

Description

Detox gets stuck waiting for an element to appear. The element is visible only the screen and the testID ist set.

When running --debug-synchronization 3000 it shows App State: undefined

Steps to Reproduce

1. Waiting for an element to be visible

Detox, Node, Device, Xcode and macOS Versions

• Detox: 7.3.3
• React Native: 0.53.0
• Node: 8.6.0
• Device: iPhone 7 Simulator (iOS 11)
• Xcode: 9.2
• macOS: 10.12.6

Device and verbose Detox logs

If just running with --debug-synchronization

endless loop of:

...
detox info Sync App State: undefined 
detox info Sync Dispatch Queue: com.apple.main-thread
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread

If just running with --debug-synchronization --loglevel verbose

...
detox verb ws
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread
detox verb ws send: {"type":"currentStatus","params":{},"messageId":7}
detox verb ws onMessage: {"type":"currentStatusResult","messageId":7,"params":{"state":"busy","resources":[{"name":"App State","info":{"elements":["<UIViewController: 0x7fb5aa410b20>"],"appState":"Waiting for window's root view controller's view to appear."}},{"name":"Dispatch Queue","info":{"queue":"<OS_dispatch_queue_main: com.apple.main-thread[0x117bb6dc0] = { xref = -2147483648, ref = -2147483648, sref = 1, target = com.apple.root.default-qos.overcommit[0x117bb8300], width = 0x1, state = 0x001ffe9e00000400, dirty, max qos 6, in-flight = 0, thread = 0x403 }>","prettyPrint":"com.apple.main-thread"}}],"messageId":7}}
detox verb ws
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread
detox verb ws send: {"type":"currentStatus","params":{},"messageId":8}
detox verb ws onMessage: {"type":"currentStatusResult","messageId":8,"params":{"state":"busy","resources":[{"name":"App State","info":{"elements":["<UIViewController: 0x7fb5aa410b20>"],"appState":"Waiting for window's root view controller's view to appear."}},{"name":"Dispatch Queue","info":{"queue":"<OS_dispatch_queue_main: com.apple.main-thread[0x117bb6dc0] = { xref = -2147483648, ref = -2147483648, sref = 1, target = com.apple.root.default-qos.overcommit[0x117bb8300], width = 0x1, state = 0x001ffe9e00000400, dirty, max qos 6, in-flight = 0, thread = 0x403 }>","prettyPrint":"com.apple.main-thread"}}],"messageId":8}}
detox verb ws
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread
detox verb ws send: {"type":"currentStatus","params":{},"messageId":9}
detox verb ws onMessage: {"type":"currentStatusResult","messageId":9,"params":{"state":"busy","resources":[{"name":"App State","info":{"elements":["<UIViewController: 0x7fb5aa410b20>"],"appState":"Waiting for window's root view controller's view to appear."}},{"name":"Dispatch Queue","info":{"queue":"<OS_dispatch_queue_main: com.apple.main-thread[0x117bb6dc0] = { xref = -2147483648, ref = -2147483648, sref = 1, target = com.apple.root.default-qos.overcommit[0x117bb8300], width = 0x1, state = 0x001ffe9e00000400, dirty, max qos 6, in-flight = 0, thread = 0x403 }>","prettyPrint":"com.apple.main-thread"}}],"messageId":9}}
detox verb ws
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread
detox verb ws send: {"type":"currentStatus","params":{},"messageId":10}
detox verb ws onMessage: {"type":"currentStatusResult","messageId":10,"params":{"state":"busy","resources":[{"name":"App State","info":{"elements":["<UIViewController: 0x7fb5aa410b20>"],"appState":"Waiting for window's root view controller's view to appear."}},{"name":"Dispatch Queue","info":{"queue":"<OS_dispatch_queue_main: com.apple.main-thread[0x117bb6dc0] = { xref = -2147483648, ref = -2147483648, sref = 1, target = com.apple.root.default-qos.overcommit[0x117bb8300], width = 0x1, state = 0x001ffe9e00000400, dirty, max qos 6, in-flight = 0, thread = 0x403 }>","prettyPrint":"com.apple.main-thread"}}],"messageId":10}}
detox verb ws
detox info Sync App State: undefined
detox info Sync Dispatch Queue: com.apple.main-thread

I am not sure if App State: undefined is a bug that is why I posted it here in addition to stackoverflow

thank you very much in advance

[LeoNatan]

It's a bug in the Detox printer. We already have an issue on the topic of bad printing (#560).
The actual message is revealed in the verbose log:

Waiting for window's root view controller's view to appear.

Something is ill-defined in your app—I'd guess in how it is being started in the native part.

I'm tempted to close as "stack overflow", but let's see.

[LeoNatan]

I see you already have a question on Stack Overflow.

[support]

We use the issue tracker exclusively for bug reports and feature requests. This issue appears to be a general usage or support question. Instead, please ask a question on Stack Overflow with the detox tag.

[wildseansy]

I'm seeing the same thing, but only when having a .tap and reloadReactNative after the test. More details here: #691