Unable to unit test Actions having default arg values [141099045]

Fixed

Bug

Status Update

No update yet.

Description

[Deleted User]

created issue #1

Sep 16, 2019 05:32PM

Component used: Navigation
Version used: 2.0.0
Devices/Android versions reproduced on: during development; any IDE
SDK: Java

Summary:
I can't unit test any production code that tries navigating to an auto-generated Action class that has a default value. It seems (in version 2.0.0) that the default values are set by the NavController instead of baked into the auto-generated class. The result is that I get some NullPointerExceptions when trying to unit test navigation.

To reproduce:
1. In nav graph xml, add an argument having a default value to an action
<fragment
android:id="@id/screen1_fragment"
android:name="com.yourapp.yourpackage.Screen1Fragment"
<action
android:id="@+id/action_screen1_to_screen2"
app:destination="@id/screen2_fragment"
<argument
android:name="myBoolean"
app:argType="boolean"
android:defaultValue="false" />
</action>
</fragment>

2. In prod code, navigate using this action without overriding the default
NavController.navigate(Screen1FragmentDirections.actionScreen1ToScreen2());

3. In a unit test, try to verify that the screen1-to-screen2 navigation was invoked
verify(NavController).navigate(Screen1FragmentDirections.actionScreen1ToScreen2());

Expected: Unit test passes with flying colors

Actual: NullPointerException is thrown when the verify() does an equals() comparison. The auto-generated class does not contain default values, and so ActionScreen1ToScreen2.getMyBoolean() method attempts to cast a null value into a boolean, like so:

public boolean getMyBoolean() {
return (boolean) arguments.get("myBoolean");
}

Seems like a testability issue. If there's something I'm missing please let me know.

Related Issues (but not the same):
* SafeArg Builder classes doesn't contain the default values (

https://partnerissuetracker.corp.google.com/issues/140123727)

Comments

il...@google.com <il...@google.com> #2Sep 16, 2019 05:33PM

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

commit 7c6dacebb5dd68ddeec73e494c2d3b940db33b41
Author: Jeremy Woods <jbwoods@google.com>
Date: Thu Dec 02 16:04:03 2021

Prevent NavHost from compose the wrong entry

Treating the visible lists like sets to ensure that they never can
duplicate any entries and allow NavHost to choose the wrong entry to
compose.

We are opting to only treat it like a Set instead of making it into one
to ensure we will keep the snapshot funcationality of
mutableStateListOf().

RelNote: "Fixed potential crashed caused by fast switching between the
start destination and another destination using bottom nav menu items."
Test: all tests pass
Bug: 208887901

Change-Id: Ic89766e6f0527af0cd3e793643c38ea9e1f2a272

M navigation/navigation-compose/src/main/java/androidx/navigation/compose/NavHost.kt

https://android-review.googlesource.com/1909652

[Deleted User] <[Deleted User]> #3Sep 16, 2019 06:25PM

This has been fixed internally and will be available in the Navigation 2.4.0-rc01 release.

[Deleted User] <[Deleted User]> #4Sep 16, 2019 06:34PM

Maybe it is the same as the other issue I listed? Different use case but same root cause?

il...@google.com <il...@google.com> #5Sep 16, 2019 07:40PM

Assigned to jb...@google.com.

Switching to Kotlin Safe Args fixed the issue, so seems like the same issue, just on the Directions side (vs the other which is on the Args side).

ap...@google.com <ap...@google.com> #6Oct 5, 2019 12:53AM

Project: platform/frameworks/support
Branch: androidx-master-dev

commit 2180ea57914af961d4f2bb43802b42ae0d1802e0
Author: Jeremy Woods <jbwoods@google.com>
Date: Fri Oct 04 16:02:03 2019

Generate default values for Directions safe_args in Java

Currently the safe args generation for java code does not contain
default Direction args values. The default directions arg values are
provided by the Kotlin safe args generation and we should be as
uniform as possible across both languages.

Test: ./gradlew --rerun-tasks navigation:navigation-safe-args-gradle-plugin:test
Change-Id: I07b67d9c86dafff608df49a609796a71a9b3315a
navigation:navigation-safe-args-generator:test
BUG: 141099045

M navigation/navigation-safe-args-generator/src/main/kotlin/androidx/navigation/safe/args/generator/java/JavaNavWriter.kt
M navigation/navigation-safe-args-generator/src/main/kotlin/androidx/navigation/safe/args/generator/java/JavaTypes.kt
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/java_nav_writer_test/MainFragmentArgs.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/java_nav_writer_test/MainFragmentDirections.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/java_nav_writer_test/Next.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/java_nav_writer_test/SanitizedMainFragmentDirections.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/nav_generator_test/java/nested_overridden_action/SettingsDirections.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/nav_generator_test/java/nested_same_action/SettingsDirections.java
M navigation/navigation-safe-args-generator/src/tests/test-data/expected/nav_generator_test/java/nested_same_action/SettingsFragmentDirections.java

https://android-review.googlesource.com/1133433

https://goto.google.com/android-sha1/2180ea57914af961d4f2bb43802b42ae0d1802e0

jb...@google.com <jb...@google.com> #7Oct 7, 2019 05:37AM

Marked as fixed.

This has been fixed internally and will be available in the Navigation 2.2.0-beta01 release.

ra...@gmail.com <ra...@gmail.com> #8Nov 18, 2019 04:37PM

Using '2.2.0-rc02'. Putting null as a default value for a string, returns a string "@null" when getting that parameter from navArgs
<argument
android:name="deepLinkToken"
android:defaultValue="@null"
app:argType="string"
app:nullable="true" />

And:

val args by navArgs<FragmentArgs>()
args.deepLinkToken // returns "@null"

jb...@google.com <jb...@google.com> #9Nov 18, 2019 07:14PM

Re #8 - please file a separate bugs with a project that reproduce your separate issue. If the issue you are mentioning is covered by

https://issuetracker.google.com/issues/141613546, feel free to +1.