NonNullableMutableLiveDataDetector doesn't work in different cases [184830263]

Fixed

Bug

Status Update

No update yet.

Description

[Deleted User]

created issue #1

Apr 8, 2021 03:18PM

Component used: lifecycle lint Version used: 2.3.1 Devices/Android versions reproduced on:

private val liveData: MutableLiveData<String> = MutableLiveData<String>("Some string")

init {
  liveData.value = null // Lint gives error about this line

}

If I remove <String> from initialization, lint doesn't fail. This is not an error.

private val liveData: MutableLiveData<String> = MutableLiveData("Some string")

init {
  liveData.value = null // This is OK but lint should have failed
}

If I remove private modifier, lint doesn't fail. This is not an error.

private val liveData: MutableLiveData<String> = MutableLiveData<String>("Some string")

init {
  liveData.value = null // This is OK but lint should have failed
}

MutableLiveDataLintFail 2.zip

1.2 MB

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Comments

se...@google.com <se...@google.com> Apr 8, 2021 03:21PM

Reassigned to jb...@google.com.

[Deleted User] <[Deleted User]> #2Apr 8, 2021 03:22PM

./gradlew :app:lintDebug --no-daemon is used for running lint. But Android Studio also doesn't show any error on expected lines.

ko...@gmail.com <ko...@gmail.com> #3Apr 17, 2021 11:14AM

I opened a PR to improve NonNullableMutableLiveDataDetector's type references check.

https://github.com/androidx/androidx/pull/161

ap...@google.com <ap...@google.com> #4May 6, 2021 03:47PM

Marked as fixed.

Project: platform/frameworks/support
Branch: androidx-main

commit 655e08dca6e27aa15c862132914cb61b0ec29fdf
Author: Sinan Kozak <kozaxinan@gmail.com>
Date: Wed May 05 16:38:12 2021

[GH] [Lifecycle] [Lint] fixes

b/184830263

Lint should use check reference too

## Proposed Changes

- Fix NonNullableMutableLiveDataDetector for [different cases](

https://issuetracker.google.com/issues/184830263). It is possible to only set type reference and omit call's generic argument.
- Added check for generic values because default upper bound of generic (if none specified) is Any?. If generic is not specified as `<T : Any>`, `T` can be defined null at call site.

https://kotlinlang.org/docs/generics.html#upper-bounds

## Testing

Test: Run NonNullableMutableLiveDataDetectorTest with new edge cases.
`nullLiteralFailMultipleFields` : Added type reference
`justKotlinObject` : Add additional test to prevent ArrayIndexOutOfBoundsException. It is fixed in

https://github.com/androidx/androidx/commit/428f0ec685ff80035c0511c0cdb12b9770b6159c but not tested. It is reported here with [

b/184830262

](

https://issuetracker.google.com/issues/184830262)
`genericParameterDefinition` : Generics are assumed as nullable, lint should ignore.

## Issues Fixed

Fixes: The bug on [

b/184830263

](

https://issuetracker.google.com/issues/184830263) being fixed
Fixes: Tests [

b/184830262

](

https://issuetracker.google.com/issues/184830263)

This is an imported pull request from

https://github.com/androidx/androidx/pull/161.

Resolves #161
Github-Pr-Head-Sha: e96b4a8e860002feccd455e9ad8dcdd868dff2df
GitOrigin-RevId: eb21c2ef19da5465be438c928d9b6ba2498b72e8
Change-Id: Id6cd01e9ec6b79a3f14b569b53d79627c79b9866

M lifecycle/lifecycle-livedata-core-ktx-lint/src/main/java/androidx/lifecycle/lint/NonNullableMutableLiveDataDetector.kt
M lifecycle/lifecycle-livedata-core-ktx-lint/src/test/java/androidx/lifecycle/lint/NonNullableMutableLiveDataDetectorTest.kt

https://android-review.googlesource.com/1697465

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