[Java] Embed Rust CLI runtime 4.8: E2E integration test

[edburns]

Overview

Create a Failsafe integration test that exercises the InProcess FFI transport end-to-end with a real runtime.node binary: client connects, creates a session, sends a message, and receives a response — all via the InProcess transport through FfiRuntimeHost.

This is task 4.8 of 9 in the implementation plan. Tasks are assigned, completed, and merged serially in this listed order. Tasks 4.1–4.7 are complete on the base branch before this task begins.

Branch: edburns/1917-java-embed-rust-cli-runtime-dd-3039145 on upstream

Plan and supporting resources

On the edburns/1917-java-embed-rust-cli-runtime-dd-3039145 branch, the directory 1917-java-embed-rust-cli-runtime-remove-before-merge contains the plan (1917-embed-cli-runtime-ignorance-reduction-plan.md) and supporting resources (spikes, prototypes, diagrams).

Read the entire plan before working.

Relevant plan sections to carefully re-read

• Section 3.11 — E2E testing with InProcess transport — Resolution: Read the full evidence in 1917-java-embed-rust-cli-runtime-remove-before-merge/spike-3-11-replay-proxy-and-in-process/. Key answers:
  1. Replay proxy works with InProcess — the replay proxy intercepts HTTP calls to COPILOT_API_URL. The runtime reads COPILOT_API_URL from the native process environment block.
  2. Use real runtime.node binary — from the copilot-native module (task 4.7).
  3. No mock native library for E2E — only unit tests use mocks.
  4. Reuse existing YAML snapshots — HTTP traffic is identical regardless of transport.
  5. Run full E2E suite under both transports — subprocess (existing job A) and InProcess (new job B with -Pinprocess Maven profile).
• InProcessEnvGuard requirement — calls SetEnvironmentVariableW (Windows) or setenv() (Linux/macOS) via JNA to mutate process environment before host_start. Restores on close(). See spike-3-11/java-inprocess-e2e-win32-x64/ for proven implementation.
• Concurrency must be 1 — InProcessEnvGuard mutates process-global state. Use surefire.forkCount=1 or JUnit 5 @ResourceLock.
• @SkipInProcess annotation — JUnit 5 condition annotation for tests incompatible with InProcess transport (e.g., per-client environment variables — see issue [Tracking] In-process (FFI) items to be cleaned up #1934).
• Section 3.12 — CI/CD workflow changes — Resolution: New java-sdk-inprocess job in java-sdk-tests.yml. Activates -Pinprocess Maven profile. Scope: ubuntu-latest (linux-x64) only.
• Section 4.8 — E2E integration test (the primary task description).
• Hard scope invariant: Linux-x64 only. No other platform E2E tests in this phase.

Resolved decisions that constrain this task

• Maven profile for InProcess: -Pinprocess profile with properties:
  • COPILOT_SDK_DEFAULT_CONNECTION=inprocess
  • forkCount=1, parallel=none in maven-failsafe-plugin
• InProcessEnvGuard — Must be created in com.github.copilot.ffi (or test harness package). Calls native env-setting functions via JNA. Implements AutoCloseable.
• E2ETestContext.createClient() dispatch — When COPILOT_SDK_DEFAULT_CONNECTION=inprocess, apply InProcessEnvGuard before starting client. Close in @AfterEach / try-with-resources.
• Test reuse — Existing YAML snapshots work. The spike confirmed a successful ping-pong round trip via InProcess transport in 1.1s.
• ABI version sensitivity — Version 1.0.73+ from nodejs/package-lock.json is required (has copilot_runtime_host_start).

Deliverables

Files to create

1. java/sdk/src/test/java/com/github/copilot/e2e/InProcessTransportIT.java — Failsafe IT that:

   • Starts the replay proxy (via E2ETestContext / CapiProxy).
   • Uses InProcessEnvGuard to set COPILOT_API_URL in the native process environment.
   • Creates a CopilotClient with RuntimeConnection.forInProcess().
   • Exercises: connect → create session → send message → receive response → disconnect.
   • Verifies the response is received correctly.
   • Cleans up: client close, env guard restore, proxy shutdown.

2. java/sdk/src/test/java/com/github/copilot/ffi/InProcessEnvGuard.java (or in test harness package) — Utility that:

   • Saves current env values for specified keys.
   • Calls SetEnvironmentVariableW (Windows) or setenv() (Linux/macOS) via JNA.
   • Implements AutoCloseable — restores saved values on close().
   • Uses JNA for cross-platform native env manipulation.

3. java/sdk/src/test/java/com/github/copilot/e2e/SkipInProcess.java (optional) — JUnit 5 @DisabledIf condition annotation for tests incompatible with InProcess transport.

Files to modify

4. java/sdk/pom.xml — Add the -Pinprocess Maven profile:

   <profile>
     <id>inprocess</id>
     <properties>
       <COPILOT_SDK_DEFAULT_CONNECTION>inprocess</COPILOT_SDK_DEFAULT_CONNECTION>
     </properties>
     <build>
       <plugins>
         <plugin>
           <groupId>org.apache.maven.plugins</groupId>
           <artifactId>maven-failsafe-plugin</artifactId>
           <configuration>
             <forkCount>1</forkCount>
             <parallel>none</parallel>
             <environmentVariables>
               <COPILOT_SDK_DEFAULT_CONNECTION>inprocess</COPILOT_SDK_DEFAULT_CONNECTION>
             </environmentVariables>
           </configuration>
         </plugin>
       </plugins>
     </build>
   </profile>

5. Snapshot files — Reuse existing snapshots or create new ones as needed for the InProcess smoke test.

Gating tests and criteria

1. InProcess E2E passes: InProcessTransportIT passes on ubuntu-latest with the real runtime.node binary on classpath.
2. Full lifecycle verified: Client connects, creates session, sends message, receives response — all via InProcess FFI transport.
3. Env guard works: InProcessEnvGuard correctly sets and restores native process environment variables.
4. Profile activation: mvn verify -Pinprocess runs the InProcess E2E tests with forkCount=1.
5. Standard E2E unaffected: mvn verify (without -Pinprocess) runs existing subprocess E2E tests unchanged.
6. All prior tests pass: mvn verify from java/ passes.
7. Spotless compliance: mvn spotless:check passes.

Out of scope

• Running the full E2E suite under InProcess transport (this task creates the smoke test; running the full suite under both transports is a CI concern handled in task 4.9).
• Testing on any platform other than linux-x64.
• CI workflow changes (task 4.9).