Bug in map() and switchMap() when used with Compose's observeAsState() [269479952]

Fixed

Bug

Status Update

No update yet.

Description

g....@xe.gr

created issue #1

Feb 16, 2023 08:39AM

Component used: livecycle-livedata-ktx Version used: 2.5.1

Issue 214434197 was reported for distinctUntilChanged() which does not set the initial value of the returned LiveData even if the source one was initialized. This caused unnecessary recompositions if observed with observeAsState().

However, I also noticed that the other two Transformations methods, map and switchMap, suffer from the same symptom which means that they too will likely cause the same unnecessary recompositions.

    @Test
    fun `map() should return livedata with trasformed initial value of source`() {
        // given
        val initialValue = "barboutsala"
        val source = MutableLiveData(initialValue)

        // when
        val mapped = source.map { it }

        // then
        assertEquals(initialValue, source.value)
        assertEquals(initialValue, mapped.value) // <-- this fails
    }

    @Test
    fun `switchMap() should return livedata with same initial value as source`() {
        // given
        val initialValue1 = "barboutsala 1"
        val initialValue2 = "barboutsala 2"
        val original = MutableLiveData(true)
        val source1 = MutableLiveData(initialValue1)
        val source2 = MutableLiveData(initialValue2)

        // when
        val switched = original.switchMap { if (it) source1 else source2 }

        // then
        assertEquals(initialValue1, source1.value)
        assertEquals(initialValue1, switched.value) // <-- this fails

        original.value = false
        assertEquals(initialValue2, source2.value)
        assertEquals(initialValue2, switched.value) // <-- this also fails!
    }

Comments

il...@google.com <il...@google.com> May 10, 2023 11:13PM

Assigned to sa...@google.com.

ap...@google.com <ap...@google.com> #2Aug 31, 2023 12:02AM

http://r.android.com/2989145

sa...@google.com <sa...@google.com> Aug 31, 2023 12:45AM

Marked as fixed.

g....@xe.gr <g....@xe.gr> #3Aug 31, 2023 07:08AM

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

commit b4d5b1c0ff880fe411cb0820e2503f91c4c23440
Author: Jake Wharton <jw@squareup.com>
Date: Tue Mar 05 23:14:25 2024

Invert dependency between lifecycle-runtime-compose and compose-ui-ui

This breaks an effective dependency cycle between library groups and will enable the future use of lifecycle-runtime-compose in a multiplatform context without a Compose UI dependency.

Before:
lifecycle-runtime-compose --> compose-ui-ui --> [lifecycle-runtime & compose-runtime]

After:
compose-ui-ui --> lifecycle-runtime-compose --> [lifeycle-runtime & compose-runtime]

The definition of the LocalLifecycleOwner composition local previosly lived in compose-ui-ui, which is why lifecycle-runtime-compose took a dependency on it. That composition local provided a LifecycleOwner into the Compose UI-based composition, and lifecycle-runtime-compose provided APIs on top of that LifecycleOwner.

The entirety of lifecycle-runtime-compose's APIs were built on lifecyle-runtime and compose-runtime with the sole exception being the use of the composition local to obtain the LifecycleOwner. By defining the composition local directly within lifecyle-runtime-compose, the dependency can be inverted making compose-ui-ui depend on it (it already depended on the regular runtime). This automatically exposes the Compose-based lifecycle APIs to downstream users of Compose UI and opens up usage of those APIs in compositions other than that provided by Compose UI (e.g., Molecule).

Bug: 328263448
Test: ./gradlew -p compose/ui bOS
Test: ./gradlew -p lifecycle bOS
Relnote: `LocalLifecycleOwner` moved from Compose UI to lifecycle-runtime-compose so that its Compose-based helper APIs can be used outside of Compose UI.
Change-Id: I6c41b92eb6aaab67e7d733dfe3fe0b429b46becf

M camera/integration-tests/avsynctestapp/build.gradle
M compose/ui/ui/build.gradle
M compose/ui/ui/src/androidMain/kotlin/androidx/compose/ui/platform/AndroidCompositionLocals.android.kt
M lifecycle/lifecycle-runtime-compose/api/current.txt
M lifecycle/lifecycle-runtime-compose/api/restricted_current.txt
M lifecycle/lifecycle-runtime-compose/build.gradle
M lifecycle/lifecycle-runtime-compose/src/androidTest/java/androidx/lifecycle/compose/DropUnlessLifecycleTest.kt
M lifecycle/lifecycle-runtime-compose/src/androidTest/java/androidx/lifecycle/compose/LifecycleEffectTest.kt
M lifecycle/lifecycle-runtime-compose/src/main/java/androidx/lifecycle/compose/DropUnlessLifecycle.kt
M lifecycle/lifecycle-runtime-compose/src/main/java/androidx/lifecycle/compose/FlowExt.kt
M lifecycle/lifecycle-runtime-compose/src/main/java/androidx/lifecycle/compose/LifecycleEffect.kt
A lifecycle/lifecycle-runtime-compose/src/main/java/androidx/lifecycle/compose/LocalLifecycleOwner.kt
M wear/compose/integration-tests/navigation/build.gradle

https://android-review.googlesource.com/2989145

il...@google.com <il...@google.com> #4Aug 31, 2023 07:25PM

The previous commit failed with

Buildbot Version: androidbuild_buildbot_20240304.00_RC00
Machine: abfarm-release-2004-0215
DIST_DIR=/buildbot/dist_dirs/aosp-androidx-main-linux-androidx/11562588 CHANGE_INFO=/buildbot/tmp/11562588-changeInfo frameworks/support/busytown/androidx.sh

############################################################################
Attempting to locate the relevant error messages via build_log_simplifier.py
############################################################################

Detected these failing tasks: []
> Configure project :internal-testutils-datastore

See the complete report at file://$SUPPORT/build/reports/configuration-cache/5whbbutylhu6d1sxb4ux0tn7b/29qe89nib49qplwpe4enj9tlr/configuration-cache-report.html

FAILURE: Build failed with an exception.

* What went wrong:
Could not determine the dependencies of task ':test:uiautomator:integration-tests:testapp:compileDebugAndroidTestKotlin'.
> Could not resolve all dependencies for configuration ':test:uiautomator:integration-tests:testapp:debugAndroidTestCompileClasspath'.
   > Unable to align dependencies in configurations 'debugRuntimeClasspath' and 'debugAndroidTestRuntimeClasspath', as both require 'project :annotation:annotation', 'project :lifecycle:lifecycle-common'.
     [Recommended action] Add the following dependencies to $SUPPORT/test/uiautomator/integration-tests/testapp/build.gradle: 
     androidTestImplementation(project(":annotation:annotation"))
     androidTestImplementation(project(":lifecycle:lifecycle-common"))

> Get more help at https://help.gradle.org.

* Exception is:
org.gradle.api.internal.tasks.TaskDependencyResolveException: Could not determine the dependencies of task ':test:uiautomator:integration-tests:testapp:compileDebugAndroidTestKotlin'.
Caused by: org.gradle.api.internal.artifacts.ivyservice.DefaultLenientConfiguration$ArtifactResolveException: Could not resolve all dependencies for configuration ':test:uiautomator:integration-tests:testapp:debugAndroidTestCompileClasspath'.
Caused by: com.android.builder.errors.EvalIssueException: Unable to align dependencies in configurations 'debugRuntimeClasspath' and 'debugAndroidTestRuntimeClasspath', as both require 'project :annotation:annotation', 'project :lifecycle:lifecycle-common'.
[Recommended action] Add the following dependencies to $SUPPORT/test/uiautomator/integration-tests/testapp/build.gradle: 
androidTestImplementation(project(":annotation:annotation"))
androidTestImplementation(project(":lifecycle:lifecycle-common"))
	at com.android.builder.errors.IssueReporter.reportError(IssueReporter.kt:131)
	at com.android.build.gradle.internal.dependency.ConstraintHandler$checkConfigurationAlignments$1.execute(ConstraintHandler.kt:64)
	at com.android.build.gradle.internal.dependency.ConstraintHandler$checkConfigurationAlignments$1.execute(ConstraintHandler.kt:33)
	at jdk.proxy1/jdk.proxy1.$Proxy64.afterResolve(Unknown Source)
Caused by: java.lang.RuntimeException: Unable to align dependencies in configurations 'debugRuntimeClasspath' and 'debugAndroidTestRuntimeClasspath', as both require 'project :annotation:annotation', 'project :lifecycle:lifecycle-common'.
[Recommended action] Add the following dependencies to $SUPPORT/test/uiautomator/integration-tests/testapp/build.gradle: 
androidTestImplementation(project(":annotation:annotation"))
androidTestImplementation(project(":lifecycle:lifecycle-common"))
	at com.android.build.gradle.internal.dependency.ConstraintHandler$checkConfigurationAlignments$1.execute(ConstraintHandler.kt:66)

BUILD FAILED in 4m 41s

I am reverting it

pr...@google.com <pr...@google.com> #5Sep 6, 2023 07:55PM

The revert was reverted in https://android-review.googlesource.com/3000040

Thanks for submitting this fix!

Issue 269479952