feat: integrate eppo module with android-sdk-framework (v3 → v4 migration) by typotter · Pull Request #252 · Eppo-exp/android-sdk

typotter · 2026-03-24T15:40:52Z

Summary

Migrates the eppo module from v3 SDK to v4 framework, completing the integration started in #251.

Dependencies

Depends on: #251 (must be merged first)

Major Changes

EppoClient Migration (v3 → v4)

Extends AndroidBaseClient from framework instead of v3 BaseEppoClient
Removes v3 dependencies
Adds framework dependency
Removes old storage classes: ConfigurationStore, ConfigCacheFile, BaseCacheFile (now in framework)

New v4 Components

OkHttpEppoClient: HTTP client implementation with slf4j logging
JacksonConfigurationParser: JSON parsing for v4 FlagConfigResponse format
Jackson adapters: Custom serializers/deserializers for EppoValue, FlagConfigResponse, dates

Example App

CustomClientActivity: Demonstrates custom HTTP client and parser injection
GsonConfigurationParser: Example alternative to Jackson parser
HeaderInjectingEppoClient: Example custom HTTP headers

Test Results

✅ 46/46 instrumentation tests passing locally
✅ Framework module builds independently
✅ Eppo module builds with v4 dependencies
✅ No breaking API changes for SDK users

Migration Notes

Cache files use .ser extension (Java serialization)
Configuration format changed from v3 to v4 JSON structure
All existing tests adapted and passing
Supersedes feat: integrate eppo module with android-sdk-framework (v3 → v4 migration) #249

…ation) Migrate EppoClient from v3 SDK to v4 framework, resolving all test failures. ## Major Changes ### EppoClient Migration - Extend AndroidBaseClient from framework instead of BaseEppoClient - Remove old ConfigurationStore, ConfigCacheFile, BaseCacheFile (now in framework) - Add dependency on android-sdk-framework module - Remove v3 sdk-common-jvm dependency ### New Components - OkHttpEppoClient: HTTP client implementation with logging - JacksonConfigurationParser: JSON parsing for v4 format - Jackson adapters for EppoValue, FlagConfigResponse, dates, etc. ### Test Infrastructure Fixes - TestConfigCacheFile: Fix filename to match framework (eppo-sdk-flags-{suffix}.ser) - Fix waitForPopulatedCache(): Remove incorrect .ser suffix (already in filename) - Fix unclosed OutputStreams: Add try-with-resources (3 locations) - Simplify testDifferentCacheFilesPerKey: Copy actual cache instead of custom JSON - Add OutputStream import ### Example App Updates - Add CustomClientActivity demonstrating custom HTTP client - Add GsonConfigurationParser and HeaderInjectingEppoClient examples ## Test Results - All 46 instrumentation tests passing locally - Framework module builds independently - Eppo module builds with v4 dependencies

- Fix TestConfigCacheFile.cacheFileName() to use correct format (eppo-sdk-flags-{suffix}.ser) - Simplify testDifferentCacheFilesPerKey to copy actual cache instead of custom JSON - Fix unclosed OutputStreams with try-with-resources (3 locations) These fixes resolve all test failures and ensure 46/46 tests pass.

…I 26-32 compatibility

…or handling - Move GsonConfigurationCodec to example module (it's a demo/example codec, not part of the framework public API) - Update CustomClientActivity to use GsonConfigurationCodec + FileBackedConfigStore to demonstrate human-readable JSON cache - Fix initialization error handling in AndroidBaseClient and EppoClient: complete exceptionally when ex != null, avoiding double increment of failCount

- eppo: 4.12.1 -> 4.12.1-SNAPSHOT - android-sdk-framework: 0.1.0 -> 0.1.0-SNAPSHOT - Remove duplicate sdk-common-jvm implementation dependency (already declared as api) - Update publish-snapshot workflow to stage and publish android-sdk-framework before eppo, so the transitive dependency is resolvable by customers

…rk migration)

- EppoValueSerializer: fix independent if-chain to if/else-if so only one value is written per serialization call; previously the else branch always wrote null after any non-array type - BanditParametersResponseDeserializer: use fields() instead of iterator() to get map key directly, consistent with FlagConfigResponseDeserializer - DateSerializer: fix Javadoc (said "gson", now says "Jackson") - OkHttpEppoClient: remove duplicate android.util.Log calls; use only slf4j throughout - EppoClientTest: add ignoreCachedConfiguration(true) to graceful init failure test to make behavior deterministic; restore testErrorGracefulModeOn and testErrorGracefulModeOff using the v4 configurationClient() API; fix waitForPopulatedCache to poll at 100ms intervals without a magic byte-size threshold - Delete android-batteries-included-notes.md (development scratch file) - Delete GsonConfigurationCodec: uses reflection on private fields of Configuration; R8 will rename those fields in release builds (minifyEnabled true, no keep rules), causing NoSuchFieldException at runtime - CustomClientActivity: replace GsonConfigurationCodec with default ConfigurationCodec.Default; update log messages accordingly

Update example/build.gradle to depend on cloud.eppo:android-sdk:5.0.0-SNAPSHOT instead of the local :eppo project, and update settings.gradle to only include the example module so the build exercises the published SDK path.

typotter · 2026-03-24T18:37:56Z

@copilot review

Copilot

Pull request overview

Migrates the eppo Android SDK module from the v3 client implementation to the v4 android-sdk-framework, updating configuration storage/parsing + HTTP fetching, and adapting the example app, tests, and snapshot publishing to the new structure.

Changes:

Refactors EppoClient to extend AndroidBaseClient (framework) and switches to framework-backed configuration storage.
Adds v4-compatible HTTP + parsing components (OkHttpEppoClient, JacksonConfigurationParser, Jackson adapters/modules).
Updates example app + instrumentation tests + snapshot publishing workflow for the new framework integration.

Reviewed changes

Copilot reviewed 32 out of 32 changed files in this pull request and generated 11 comments.

Show a summary per file

File	Description
`settings.gradle`	Updates included Gradle modules.
`example/src/main/res/values/strings.xml`	Adds label for new example launch option.
`example/src/main/res/layout/activity_main.xml`	Adds new button to start the custom client example.
`example/src/main/java/cloud/eppo/androidexample/SecondActivity.java`	Tweaks assignment default + logging in example flow.
`example/src/main/java/cloud/eppo/androidexample/MainActivity.java`	Adds custom-client launch button and updates cache clearing to framework cache file.
`example/src/main/java/cloud/eppo/androidexample/HeaderInjectingEppoClient.java`	New example `EppoConfigurationClient` wrapper that injects headers via OkHttp interceptor.
`example/src/main/java/cloud/eppo/androidexample/GsonConfigurationParser.java`	New example GSON-based parser implementation (reference).
`example/src/main/java/cloud/eppo/androidexample/CustomClientActivity.java`	New example activity demonstrating custom HTTP client + parser injection into `AndroidBaseClient`.
`example/src/main/java/cloud/eppo/androidexample/Constants.java`	Updates example defaults for subject/flag.
`example/src/main/AndroidManifest.xml`	Registers `CustomClientActivity`.
`example/build.gradle`	Switches example to consume published SDK snapshot + adds OkHttp dependency.
`eppo/src/main/java/cloud/eppo/android/dto/adapters/FlagConfigResponseDeserializer.java`	New Jackson deserializer for v4 `FlagConfigResponse`.
`eppo/src/main/java/cloud/eppo/android/dto/adapters/EppoValueSerializer.java`	New Jackson serializer for `EppoValue`.
`eppo/src/main/java/cloud/eppo/android/dto/adapters/EppoValueDeserializer.java`	New Jackson deserializer for `EppoValue`.
`eppo/src/main/java/cloud/eppo/android/dto/adapters/EppoModule.java`	New Jackson `SimpleModule` wiring custom serializers/deserializers.
`eppo/src/main/java/cloud/eppo/android/dto/adapters/DateSerializer.java`	New Date serializer (UTC ISO).
`eppo/src/main/java/cloud/eppo/android/dto/adapters/BanditParametersResponseDeserializer.java`	New Jackson deserializer for v4 bandit params response.
`eppo/src/main/java/cloud/eppo/android/PrecomputedCacheFile.java`	Switches cache base class import to framework `BaseCacheFile`.
`eppo/src/main/java/cloud/eppo/android/OkHttpEppoClient.java`	Adds default OkHttp implementation of `EppoConfigurationClient` with slf4j logging.
`eppo/src/main/java/cloud/eppo/android/JacksonConfigurationParser.java`	Adds default Jackson-based `ConfigurationParser` using the new `EppoModule`.
`eppo/src/main/java/cloud/eppo/android/EppoClient.java`	Migrates client to `AndroidBaseClient` + adds builder injection for parser/http client/store.
`eppo/src/main/java/cloud/eppo/android/ConfigurationStore.java`	Removes v3 storage implementation (moved to framework).
`eppo/src/main/java/cloud/eppo/android/ConfigCacheFile.java`	Removes v3 cache file implementation (moved to framework).
`eppo/src/main/java/cloud/eppo/android/BaseCacheFile.java`	Removes v3 cache base class (moved to framework).
`eppo/src/androidTest/java/cloud/eppo/android/helpers/AssignmentTestCaseDeserializer.java`	Updates imports/deserialization to v4 DTOs/adapters.
`eppo/src/androidTest/java/cloud/eppo/android/helpers/AssignmentTestCase.java`	Updates v4 DTO import usage.
`eppo/src/androidTest/java/cloud/eppo/android/TestConfigCacheFile.java`	Adds test helper cache file aligned to framework naming/extension.
`eppo/src/androidTest/java/cloud/eppo/android/EppoClientTest.java`	Refactors tests to inject v4 HTTP client + updated cache serialization + offline init parsing.
`eppo/build.gradle`	Bumps SDK version, switches to framework + v4 common dependency, adds Jackson module dep.
`android-sdk-framework/src/main/java/cloud/eppo/android/framework/AndroidBaseClient.java`	Tweaks initialization failure handling/logging behavior.
`android-sdk-framework/build.gradle`	Marks framework version as `-SNAPSHOT`.
`.github/workflows/publish-snapshot.yml`	Expands snapshot publishing to framework + new branch trigger.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2026-03-27T14:40:28Z

settings.gradle

 rootProject.name = "Eppo SDK"
-include ':example'
-include ':eppo'
-include ':android-sdk-framework'
+include ':example'


settings.gradle now only includes :example, but this repo still has :eppo and :android-sdk-framework modules and the build/workflows reference them. With these includes removed, Gradle will fail to resolve project(':android-sdk-framework') (and any tasks like eppo:publish). Re-add the missing include ':eppo' and include ':android-sdk-framework' entries (or otherwise update the build to match the intended module structure).

Copilot · 2026-03-27T14:40:28Z

example/src/main/java/cloud/eppo/androidexample/MainActivity.java

+    ConfigCacheFile cacheFile =
+        new ConfigCacheFile(
+            getApplication(), cacheFileNameSuffix, "application/x-java-serialized-object");
+    if (cacheFile.exists()) {


The cache file content-type is hard-coded as a string literal ("application/x-java-serialized-object"). Since the framework already exposes this via ConfigurationCodec.Default#getContentType(), using the codec (or a shared constant) would avoid drift if the framework changes its default content type/extension mapping.

Copilot · 2026-03-27T14:40:29Z

example/src/main/java/cloud/eppo/androidexample/SecondActivity.java

+    //    AssignmentDetails<Boolean> details =         EppoClient.getInstance()
+    //            .getBooleanAssignmentDetails(experimentKey, subjectId, new Attributes(), false);


There is commented-out assignment/details code left in handleAssignment(). This makes the example harder to read and tends to bitrot; either remove it or convert it into a real, working example (e.g., behind a button / feature flag) so it stays exercised.

Suggested change

// AssignmentDetails<Boolean> details = EppoClient.getInstance()

// .getBooleanAssignmentDetails(experimentKey, subjectId, new Attributes(), false);

Copilot · 2026-03-27T14:40:29Z

example/src/main/java/cloud/eppo/androidexample/Constants.java

+  public static final String INITIAL_SUBJECT_ID = "jsmith123";
+  public static final String INITIAL_FLAG_KEY = "ai-metric-explores";


Constants now hard-codes a specific subject ID and flag key. This can make the example app behave unexpectedly for most users (and can accidentally hit real flags if the API key is set). Consider keeping these as empty/default placeholders or using clearly fake sample values (e.g., "example-flag") to avoid implying production defaults.

Suggested change

public static final String INITIAL_SUBJECT_ID = "jsmith123";

public static final String INITIAL_FLAG_KEY = "ai-metric-explores";

public static final String INITIAL_SUBJECT_ID = "example-subject-id";

public static final String INITIAL_FLAG_KEY = "example-flag-key";

Copilot · 2026-03-27T14:40:29Z

eppo/src/main/java/cloud/eppo/android/EppoClient.java

      if (instance.getInitialConfigFuture() != null) {
        instance
            .getInitialConfigFuture()
            .handle(
                (success, ex) -> {


If offlineMode is true and instance.getInitialConfigFuture() is null, ret is never completed (no fetch is started and the getInitialConfigFuture() handler won't run). This can hang buildAndInitAsync() forever. Add an offline-mode completion fallback when there is no initial config future (as done in AndroidBaseClient.Builder).

Copilot · 2026-03-27T14:40:30Z

eppo/src/main/java/cloud/eppo/android/OkHttpEppoClient.java

+  private Request buildRequest(EppoConfigurationRequest request) {
+    HttpUrl.Builder urlBuilder =
+        HttpUrl.parse(request.getBaseUrl() + request.getResourcePath()).newBuilder();
+


HttpUrl.parse(...) can return null if the constructed URL is invalid; calling .newBuilder() on it will then throw an NPE. It would be safer to validate the parsed URL and fail the returned future with a clear exception (including the baseUrl/resourcePath) when parsing fails.

Copilot · 2026-03-27T14:40:30Z

.github/workflows/publish-snapshot.yml

-      - name: Stage snapshot artifact
-        run: ./gradlew eppo:assemble eppo:publish -Psnapshot
+      - name: Stage snapshot artifacts
+        run: ./gradlew android-sdk-framework:assemble android-sdk-framework:publish eppo:assemble eppo:publish -Psnapshot


The workflow runs android-sdk-framework:publish / eppo:publish in the "Stage snapshot artifacts" step and then runs publishAllPublicationsToMavenCentralRepository for each module afterwards. Since publish already triggers PublishToMavenRepository tasks, this is likely redundant and can double-publish (or fail with "already published"). Consider making the staging step assemble-only (or publish to MavenLocal) and keep the actual Maven Central publishing in the dedicated steps.

Suggested change

run: ./gradlew android-sdk-framework:assemble android-sdk-framework:publish eppo:assemble eppo:publish -Psnapshot

run: ./gradlew android-sdk-framework:assemble eppo:assemble -Psnapshot

Copilot · 2026-03-27T14:40:30Z

example/src/main/java/cloud/eppo/androidexample/MainActivity.java

+    //    if (!TextUtils.isEmpty(INITIAL_FLAG_KEY)) {
+    //      EppoClient.getInstance().getStringAssignment(INITIAL_FLAG_KEY, INITIAL_SUBJECT_ID, "");
+    //    }


The onResume() assignment test block is now commented out. If this behavior is no longer desired, prefer removing the dead code entirely; otherwise, consider guarding it behind a debug flag so the intent stays clear and it doesn't accumulate commented-out logic.

Copilot · 2026-03-27T14:40:31Z

eppo/src/androidTest/java/cloud/eppo/android/EppoClientTest.java

+      @Nullable CachingConfigurationStore configurationStoreOverride,
      String apiKey,
      boolean offlineMode,
      IAssignmentCache assignmentCache,
-      boolean ignoreConfigCacheFile) {
+      boolean ignoreTestConfigCacheFile) {


The ignoreTestConfigCacheFile parameter on initClient(...) is currently unused. This makes the helper signature misleading and risks tests diverging from intended behavior. Either remove the parameter or wire it up (e.g., to builder.ignoreCachedConfiguration(...) / cache handling) so callers can control the cache behavior.

Copilot · 2026-03-27T14:40:31Z

eppo/src/androidTest/java/cloud/eppo/android/EppoClientTest.java

+    InputStream configStream = assets.open(filepath);
+    byte[] configBytes = IOUtils.toByteArray(configStream);


configStream is opened but never closed. Wrap this in try-with-resources (or explicitly close the stream) to avoid leaking file descriptors during the instrumentation test run.

Suggested change

InputStream configStream = assets.open(filepath);

byte[] configBytes = IOUtils.toByteArray(configStream);

byte[] configBytes;

try (InputStream configStream = assets.open(filepath)) {

configBytes = IOUtils.toByteArray(configStream);

}

typotter added 12 commits March 24, 2026 09:38

fix: remove unused Configuration import

57db659

fix: add missing OutputStream import for Android API 26 compatibility

5577464

fix: replace readAllBytes() with IOUtils.toByteArray() for Android AP…

de77789

…I 26-32 compatibility

chore: bump eppo to 5.0.0-SNAPSHOT (major version bump for v4 framewo…

ce6bfcf

…rk migration)

feat: publish snapshots on snapshot/* branches

a346524

fix: use snapshot/** pattern to match nested snapshot branch names

2c10c3c

typotter mentioned this pull request Mar 24, 2026

feat: integrate eppo module with android-sdk-framework (v3 → v4 migration) #249

Closed

style: fix spotless formatting in CustomClientActivity

0cc4d2a

typotter requested a review from aarsilv March 25, 2026 22:11

aarsilv requested a review from Copilot March 27, 2026 14:32

Copilot started reviewing on behalf of aarsilv March 27, 2026 14:33 View session

Copilot AI reviewed Mar 27, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

feat: integrate eppo module with android-sdk-framework (v3 → v4 migration)#252

feat: integrate eppo module with android-sdk-framework (v3 → v4 migration)#252
typotter wants to merge 13 commits intotypo/v4/add-framework-modulefrom
typo/v4/integrate-eppo-with-framework

typotter commented Mar 24, 2026

Uh oh!

typotter commented Mar 24, 2026

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Copilot AI Mar 27, 2026

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

		// AssignmentDetails<Boolean> details = EppoClient.getInstance()
		// .getBooleanAssignmentDetails(experimentKey, subjectId, new Attributes(), false);

		public static final String INITIAL_SUBJECT_ID = "jsmith123";
		public static final String INITIAL_FLAG_KEY = "ai-metric-explores";

	run: ./gradlew android-sdk-framework:assemble android-sdk-framework:publish eppo:assemble eppo:publish -Psnapshot
	run: ./gradlew android-sdk-framework:assemble eppo:assemble -Psnapshot

		InputStream configStream = assets.open(filepath);
		byte[] configBytes = IOUtils.toByteArray(configStream);

Conversation

typotter commented Mar 24, 2026

Summary

Dependencies

Major Changes

EppoClient Migration (v3 → v4)

New v4 Components

Example App

Test Results

Migration Notes

Uh oh!

typotter commented Mar 24, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 27, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants