Provide a testable replacement for viewModelScope [264598574]

Fixed

Feature Request

Status Update

No update yet.

Description

ni...@ansman.se

created issue #1

Jan 7, 2023 01:48AM

Component used: androidx.lifecycle:lifecycle-viewmodel-ktx

Version used: 2.5.1

Devices/Android versions reproduced on: n/a

Given the new APIs for adding closables to view models, viewModelScope should probably be marked as discouraged or deprecated in order to promote testability.

Comments

ia...@gmail.com <ia...@gmail.com> #2Aug 13, 2023 12:16AM

What I'd like to see is a CoroutineScope.asClosableCoroutineScope() method and making viewModelScope a parameter that has a default value that you can override in your test to pass something tied to testScope.

il...@google.com <il...@google.com> Aug 31, 2023 07:48PM

Assigned to sa...@google.com.

il...@google.com <il...@google.com> Sep 28, 2023 10:15PM

Reassigned to il...@google.com.

il...@google.com <il...@google.com> Feb 17, 2024 12:45AM

Reassigned to mg...@google.com.

mg...@google.com <mg...@google.com> Feb 23, 2024 05:58PM

Accepted by mg...@google.com.

ap...@google.com <ap...@google.com> #3Mar 5, 2024 01:02AM

Marked as fixed.

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

commit 83e99ecaee1153dc0603e10d6123b00fb2a30eb2
Author: Marcello Galhardo <mgalhardo@google.com>
Date: Tue Feb 27 10:43:01 2024

Allow overriding a `viewModelScope` instance from a `ViewModel`

* `viewModelScope` is now an overrideable constructor parameter, allowing it to be replaced during tests.
* For KMP usage, addresses platforms where `Dispatchers.Main` may be unavailable by falling back to `EmptyCoroutineContext` (e.g., Linux).

Reasons for preferring the constructor parameter over a overrideable property:
* Reduces brittleness due to reliance on a overrideable property name.
* Opens possibilities for writing a Lint check to enforce correct usage (in teams that want to commit to always inject a `viewModelScope`).
* Maintains the existing `viewModelScope` API for minimal developer churn.

RelNote: "`ViewModel.viewModelScope` is now a overrideable constructor parameter."
Fixes: 264598574
Test: ViewModelScopeTest
Change-Id: I2817ca223e31fb3e66b1b87b470b2eb26c2fac55

M lifecycle/lifecycle-viewmodel/api/current.txt
M lifecycle/lifecycle-viewmodel/api/restricted_current.txt
M lifecycle/lifecycle-viewmodel/src/androidInstrumentedTest/kotlin/androidx/lifecycle/ViewModelScopeTest.kt
M lifecycle/lifecycle-viewmodel/src/commonMain/kotlin/androidx/lifecycle/ViewModel.kt
A lifecycle/lifecycle-viewmodel/src/commonMain/kotlin/androidx/lifecycle/viewmodel/internal/CloseableCoroutineScope.kt
M lifecycle/lifecycle-viewmodel/src/commonMain/kotlin/androidx/lifecycle/viewmodel/internal/ViewModelImpl.kt
M lifecycle/lifecycle-viewmodel/src/jvmMain/kotlin/androidx/lifecycle/ViewModel.jvm.kt
M lifecycle/lifecycle-viewmodel/src/nativeMain/kotlin/androidx/lifecycle/ViewModel.native.kt

https://android-review.googlesource.com/2984672

ap...@google.com <ap...@google.com> #4Mar 5, 2024 05:18PM

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

commit 42930bf5e811fc381f1b43e1fb0e0492e7992b02
Author: Marcello Galhardo <mgalhardo@google.com>
Date: Tue Mar 05 11:33:53 2024

Remove duplicated `VIEW_MODEL_SCOPE_KEY`

* aosp/2984672 left a unused `VIEW_MODEL_SCOPE_KEY`, replaced by `androidx.lifecycle.viewmodel.internal.VIEW_MODEL_SCOPE_KEY`.

Bug: 264598574
Test: ViewModelScopeTest
Change-Id: I6ea15a5921aa1acfd0bf427e54a5f6db19787604

M lifecycle/lifecycle-viewmodel/src/commonMain/kotlin/androidx/lifecycle/ViewModel.kt

https://android-review.googlesource.com/2988413

pr...@google.com <pr...@google.com> #5Mar 20, 2024 08:26PM

The following release(s) address this bug.It is possible this bug has only been partially addressed:

androidx.lifecycle:lifecycle-viewmodel:2.8.0-alpha03
androidx.lifecycle:lifecycle-viewmodel-android:2.8.0-alpha03