Crash after updating to Fragment Testing library v1.1.0-alpha03 [122273087]

Fixed

Bug

Status Update

No update yet.

Description

or...@gmail.com

created issue #1

Jan 3, 2019 10:38AM

Component used:fragment-testing
Version used:1.1.0-alpha03
Devices/Android versions reproduced on:

as per

https://stackoverflow.com/questions/54012481/crash-after-updating-to-fragment-testing-library-v1-1-0-alpha03?noredirect=1#comment94863696_54012481

After updating to androidx.fragment:fragment-testing v1.0-alpha03 we're now getting following crash at end of test.

```
java.lang.NullPointerException: Attempt to invoke virtual method 'java.util.Collection java.util.concurrent.ConcurrentHashMap.values()' on a null object reference
at androidx.lifecycle.ViewModel.clear(ViewModel.java:125)
at androidx.lifecycle.ViewModelStore.clear(ViewModelStore.java:62)
```

Importantly this is test where we're mocking instance of ViewModel being used and issues seems to be related to associated changes to lifecycle-viewmodel v2.1.0-alpha01 which we now have a transitive dependency to. Specifically crash is occurring in following method because mBagOfTags is null

```
final void clear() {
mCleared = true;
for (Object value: mBagOfTags.values()) {
// see comment for the similar call in setTagIfAbsent
closeWithRuntimeException(value);
}
onCleared();
}
```

repo steps:

clone

https://github.com/joreilly/galway-bus-android
checkout `fragment_test_issue ` branch
run `RouteListFragmentTest`

Comments

se...@google.com <se...@google.com> #2Jan 7, 2019 04:07PM

Still crashing with Compose 1.7.4.
I also tried moving sharedElement to BoxWithConstraints (rather than in its content), but did not help.
So the layout hierarchy looks like this (with more details and with "..." I replaced series of "normal" layouts):
NavHost -> ... -> AnimatedVisibility -> ... -> BoxWithConstraints with sharedElement -> some content
\> ... -> AnimatedVisibility -> ... -> LazyList -> ... -> Animated Visibility -> Selection container -> BoxWithConstraints with sharedElement -> some content

Any ideas?

or...@gmail.com <or...@gmail.com> #3Jan 7, 2019 04:21PM

In your BoxWithConstraints do you do any conditional composition? Things like:

if (constraintsExceedsCertainThreshold) composeSomeContent() else someOtherContent()

or...@gmail.com <or...@gmail.com> #4Jan 7, 2019 04:29PM

No, it's just a `Text` which has different style depending on constraints.
Also note `sharedElement` is put on `BoxWithContraints` now, not on the content.
Thanks!

se...@google.com <se...@google.com> #5Jan 7, 2019 04:53PM

Based on the stacktrace, it seems like the item in question is composed but never placed. Do you use custom precompose or prefetch logic in your lazy list?

or...@gmail.com <or...@gmail.com> #6Jan 7, 2019 06:21PM

No, nothing custom. Just the default prefetch logic.
There is also one `AnimatedContent` above the `BoxWithConstraints`. Could this cause issues?
Thank you for looking into this.

il...@google.com <il...@google.com> #7Jan 8, 2019 10:58PM

Marked as fixed.

The AnimatedContent never skips measuring/placing children after it composes them. So I don't expect that to be the issue.

Since you mentioned the modifier is on BoxWithConstraints rather than on the children of BoxWithConstraints, my guess is it's most likely related to LazyList.

Can you clarify what type of LazyList you are using? Is it LazyColumn/Row or LazyGrid, or something else?

Issue 122273087