feat(feature-flag): bundle catalog as Android raw resource and JVM classpath resource

[rafaeltonholo]

Contribution Summary

Linked Issue/Ticket: Resolves #11328
RFC / Technical Design (if applicable): RFC 0004: Add a Declarative Feature Flag Catalog / Technical Design 0002: Declarative Feature Flag Catalog

Description

• Add GenerateFeatureFlagRawResTask to copy catalog into res/raw for Android modules
• Bundle catalog as classpath resource for JVM target to enable plain JVM unit tests
• Add test coverage for resource generation and classpath loading

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Contribution Checklist

• I have read and affirm that my contribution adheres to Mozilla’s Community Participation Guidelines
• This contribution is in Kotlin where possible
• This contribution does not use merge commits
• This contribution adheres to the existing codestyle (run gradlew spotlessCheck to check and gradlew spotlessApply to format your source code; will be checked by CI).
• This contribution does not break existing unit tests (run gradlew testDebugUnitTest; will be checked by CI).
• This contribution includes tests for any new functionality, and maintains tests for any updated functionality.
• This contribution adheres to our Engineering process (RFC/Technical Design/ADR)
• This PR has a descriptive title and body that accurately outlines all changes made, and contains a reference to any issues that it fixes (e.g. Closes #XXX or Fixes #XXX).

[Copilot]

🟡 Changes recommended

There are correctness issues in the new test and build script (potential NPE and likely missing Gradle type import) plus an incomplete resource-name sanitization that can generate invalid Android resource filenames.

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Pull request overview

This PR packages the declarative feature-flag catalog for runtime consumption in both Android (as a generated res/raw resource) and JVM (as a classpath resource), enabling plain JVM unit tests to load the catalog without an Android runtime.

Changes:

• Add a cacheable Gradle task (GenerateFeatureFlagRawResTask) that copies the catalog into a generated Android res/raw directory with a sanitized resource name.
• Wire the generated res/ directory into :core:featureflag Android resources and also bundle the catalog into the JVM target’s processed resources.
• Add unit tests for the Gradle task and a JVM test verifying the catalog can be read from the classpath.

File summaries

File	Description
core/featureflag/src/jvmTest/kotlin/net/thunderbird/core/featureflag/FeatureFlagCatalogResourceTest.kt	Adds a JVM test that reads the catalog from the classpath.
core/featureflag/build.gradle.kts	Wires catalog generation into Android resources and includes the catalog in JVM processed resources.
build-plugin/plugin/src/test/kotlin/net/thunderbird/gradle/plugin/featureflag/task/GenerateFeatureFlagRawResTaskTest.kt	Adds unit tests validating raw resource generation behavior.
build-plugin/plugin/src/main/kotlin/net/thunderbird/gradle/plugin/featureflag/task/GenerateFeatureFlagRawResTask.kt	Introduces the cacheable task that copies/sanitizes the catalog into res/raw.
build-plugin/plugin/build.gradle.kts	Adds test dependencies needed by the new plugin tests.

Review details

• Files reviewed: 5/5 changed files
• Comments generated: 4
• Review effort level: Lite

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[Copilot]

🟡 Changes recommended

The new task currently lowercases resource names using the default locale (risking non-deterministic outputs/build-cache issues) and a couple of new tests can fail with an early NPE due to nullable classloader handling.

Once you've addressed the issues Copilot identified, you can request another Copilot review.

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Review details

Suppressed comments (3)

build-plugin/plugin/src/main/kotlin/net/thunderbird/gradle/plugin/featureflag/task/GenerateFeatureFlagRawResTask.kt:63

• Using Locale.getDefault() makes the sanitized resource name depend on the machine/user locale (e.g. Turkish locale casing), which can break deterministic outputs and build cache relocatability. Use a locale-independent mapping (e.g. Locale.ROOT) for lowercasing resource names.

            .lowercase(Locale.getDefault())

core/featureflag/src/jvmTest/kotlin/net/thunderbird/core/featureflag/FeatureFlagCatalogResourceTest.kt:18

• FeatureFlagCatalogResourceTest::class.java.classLoader is nullable, but the code dereferences it immediately; if it is ever null this will fail with a NullPointerException before the assertion. Make the failure explicit with requireNotNull(...) so the test reports a clear cause.

        val classLoader = FeatureFlagCatalogResourceTest::class.java.classLoader

build-plugin/plugin/src/test/kotlin/net/thunderbird/gradle/plugin/featureflag/task/GenerateFeatureFlagRawResTaskFunctionalTest.kt:30

• javaClass.classLoader is nullable in Kotlin; if it is null this line will throw a NullPointerException before checkNotNull runs. Wrap the classloader access in requireNotNull(...) so a missing classloader fails with a clearer message.

        val metadata = checkNotNull(javaClass.classLoader.getResourceAsStream(PLUGIN_METADATA_RESOURCE)) {

• Files reviewed: 6/6 changed files
• Comments generated: 0 new
• Review effort level: Lite

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