Fix VolumeScreenIndividualTest and VolumeScreenThemeTest

[luizgrp]

After merging #322, build step in main branch got green.

However, the PRs that are up to date with main branch started to fail with:

com.google.android.horologist.audio.ui.VolumeScreenIndividualTest > volumeScreenAtMaximum FAILED
    java.lang.NullPointerException at VolumeScreenIndividualTest.kt:66
com.google.android.horologist.audio.ui.VolumeScreenIndividualTest > volumeScreenAtMinimum FAILED
    java.lang.NullPointerException at VolumeScreenIndividualTest.kt:49
com.google.android.horologist.audio.ui.VolumeScreenIndividualTest > volumeScreenWithLongTest FAILED
    java.lang.NullPointerException at VolumeScreenIndividualTest.kt:83

---

Once again, main is green, but the PRs that are up to date with main branch started to fail with:

com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[0] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[1] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[2] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[3] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[4] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[5] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56
10 tests completed, 7 failed, 3 skipped
com.google.android.horologist.audio.ui.VolumeScreenThemeTest > volumeScreenThemes[6] FAILED
    java.lang.NullPointerException at VolumeScreenThemeTest.kt:56

[luizgrp]

These 2 classes were renamed in #223

We need to find out answers for:

• why we don't see these tests failing locally?
• why are those tests failing only for the builds for the PRs and not for the main branch?

These two things cross my mind to investigate:

1. caching that is being used in our builds in CI
2. this plugin to only trigger tests for modules which had files changed by the PR

[luizgrp]

Many tests (FigmaVolumeScreenTest, MediaPlayerScreenTest, PodcastPlayerScreenTest, MediaChipTest, ShowPlaylistChipTest, SecondaryChipTest) started failing now:

com.google.android.horologist.media.ui.FigmaVolumeScreenTest > volumePlayerScreen FAILED
    java.lang.NullPointerException at FigmaVolumeScreenTest.kt:46

...

53 tests completed, 35 failed
> Task :media-ui:testDebugUnitTest FAILED

Downloading the build artifacts I can see in the test report:

java.lang.NullPointerException: goldenImage must not be null
	at app.cash.paparazzi.SnapshotVerifier$newFrameHandler$1.handle(SnapshotVerifier.kt:53)
	at com.google.android.horologist.paparazzi.WearSnapshotHandler$newFrameHandler$1.handle(WearSnapshotHandler.kt:57)
	at app.cash.paparazzi.Paparazzi$takeSnapshots$1$2.invoke(Paparazzi.kt:302)
	at app.cash.paparazzi.Paparazzi$takeSnapshots$1$2.invoke(Paparazzi.kt:295)
	at app.cash.paparazzi.Paparazzi.withTime(Paparazzi.kt:336)
	at app.cash.paparazzi.Paparazzi.takeSnapshots(Paparazzi.kt:295)
	at app.cash.paparazzi.Paparazzi.snapshot(Paparazzi.kt:211)
	at app.cash.paparazzi.Paparazzi.snapshot(Paparazzi.kt:204)
	at app.cash.paparazzi.Paparazzi.snapshot$default(Paparazzi.kt:195)
	at com.google.android.horologist.media.ui.FigmaVolumeScreenTest.volumePlayerScreen(FigmaVolumeScreenTest.kt:46)

So it looks like it's something related to our custom snapshot handler.

[luizgrp]

Possible scenario for goldenImage to be null:

• SnapshotVerifier.kt:53 calls ImageIO.read(File) - code
• ImageIO.read(File) calls ImageIO.read(ImageInputStream) - code
• ImageIO.read(ImageInputStream) calls ImageIO.getImageReaders - code
• ImageIO.getImageReaders catches IllegalArgumentException and returns empty - code
• ImageIO.read(ImageInputStream) returns null - code
• ImageIO.read(File) returns null - code

[luizgrp]

After merging #337 (red in CI) into main branch (green in CI), main became red in CI with the same errors.

So going back to the points listed in #323 (comment):

1. Caching

Cache keys for the commit before and after are the same, however, the commit before could not find the cache:

Cache not found for input keys: gradle-317e5f085fa5f82709737fd17a8c56030dd712840d6d541df61930b48f0ea8f0

Whereas the commit after found it:

Cache restored from key: gradle-317e5f085fa5f82709737fd17a8c56030dd712840d6d541df61930b48f0ea8f0

2. affectedModuleDetector plugin

This #337 only changed one file: build.yml. Would that make the plugin indicate that all modules have been affected and hence now main is failing (because it is now testing these modules that were not being tested before)?

[luizgrp]

I can see in the archived logs for #336:

[INFO] [amd] unknownFiles: [.github/workflows/build.yml, build.gradle], changedProjects: [], buildAll: false
[INFO] [amd] checking whether I should include :audio and my answer is false
[INFO] [amd] checking whether I should include :composables and my answer is false
[INFO] [amd] checking whether I should include :compose-layout and my answer is false
[INFO] [amd] checking whether I should include :compose-tools and my answer is false
[INFO] [amd] checking whether I should include :audio-ui and my answer is false
[INFO] [amd] checking whether I should include :media-data and my answer is false
[INFO] [amd] checking whether I should include :media-sample and my answer is false
[INFO] [amd] checking whether I should include :media and my answer is false
[INFO] [amd] checking whether I should include :media-ui and my answer is false
[INFO] [amd] checking whether I should include :media3-backend and my answer is false
[INFO] [amd] checking whether I should include :paparazzi and my answer is false
[INFO] [amd] checking whether I should include :network-awareness and my answer is false
[INFO] [amd] checking whether I should include :sample and my answer is false
[INFO] [amd] checking whether I should include :tiles and my answer is false

Which seems to answer the question above that changes to build.yml would not trigger to test all modules.

[luizgrp]

Given the causes seems to be unrelated to VolumeScreenIndividualTest and VolumeScreenThemeTest themselves, this is been closed by #338 and a new issue was raised in #340