Map session.mcp.apps.callTool result to JsonNode and harden mvn clean

[edburns]

Two independent improvements to the Java SDK:

1. Fix session.mcp.apps.callTool return type — The RPC method returns a free-form JSON object but Java codegen was mapping it to Void. This change teaches the codegen to recognize free-form object schemas and map them to JsonNode.

2. Make mvn clean resilient to external file locks — External processes (VS Code language servers, orphaned Node.js test-harness processes) can hold file descriptors on target/copilot-sdk/ just long enough to cause mvn clean to fail. A two-phase clean strategy ensures target/ is fully removed.

Changes

Codegen: free-form object → JsonNode mapping

java/scripts/codegen/java.ts

• wrapperResultClassName() now recognizes free-form object schemas (type=object + additionalProperties, no properties) and returns "JsonNode" instead of falling through to Void.
• generateNamespaceApiFile() and generateRpcRootFile() import com.fasterxml.jackson.databind.JsonNode when any method in the namespace uses the JsonNode result type.

java/src/generated/java/com/github/copilot/generated/rpc/SessionMcpAppsApi.java (regenerated)

• callTool() now returns CompletableFuture<JsonNode> instead of CompletableFuture<Void>.

java/src/test/java/com/github/copilot/RpcWrappersTest.java

• 3 new unit tests using the existing StubCaller pattern:
  • sessionRpc_mcp_apps_callTool_invokes_correct_rpc_method() — verifies method name dispatch
  • sessionRpc_mcp_apps_callTool_injects_sessionId() — verifies sessionId is injected into params
  • sessionRpc_mcp_apps_callTool_returns_jsonNode_payload() — verifies the future resolves to a JsonNode with expected content

Build: harden mvn clean

java/pom.xml

• default-clean execution: set failOnError=false so transient file locks don't fail the build.
• New post-clean-sweep execution in post-clean phase: retries deletion after the transient locks have cleared, ensuring target/ is fully removed.
• Removed stale comment referencing nonexistent retryCount parameter.

Test results

All 1684 unit tests pass on both JDK 25 and JDK 17. All 6 integration tests (5 SlashCommandsIT + 1 InternalExecutorProviderIT) pass. Zero failures, zero errors.

Commits

• bfdce49c — java: map session.mcp.apps.callTool result to JsonNode
• 7206e842 — Ensure lingering content from test harness approach does not remain after mvn clean
• e391d6af — Ensure lingering content from test harness approach does not remain after mvn clean

[Copilot]

Pull request overview

Two independent Java SDK improvements: teach the codegen to map free-form JSON-RPC result objects to Jackson JsonNode (specifically fixing session.mcp.apps.callTool which was incorrectly typed as Void), and harden mvn clean against transient file locks on target/copilot-sdk/ left by the test harness.

Changes:

• Codegen: wrapperResultClassName() recognizes free-form object schemas and returns "JsonNode"; namespace/root API generators add the proper Jackson import when needed.
• Regenerated SessionMcpAppsApi.callTool now returns CompletableFuture<JsonNode> and 3 new RpcWrappersTest cases cover method dispatch, sessionId injection, and result payload.
• pom.xml: default-clean switched to failOnError=false, plus a new post-clean-sweep execution in the post-clean phase re-runs the clean goal to guarantee target/ removal.

Show a summary per file

File	Description
java/scripts/codegen/java.ts	Adds JsonNode mapping for free-form object results and adjusts import collection in namespace/root API generators.
java/src/generated/java/com/github/copilot/generated/rpc/SessionMcpAppsApi.java	Regenerated: callTool returns CompletableFuture<JsonNode> with proper import.
java/src/test/java/com/github/copilot/RpcWrappersTest.java	Adds three unit tests covering callTool dispatch, sessionId injection, and JsonNode payload resolution.
java/pom.xml	Splits maven-clean-plugin into a tolerant default-clean and a follow-up post-clean-sweep execution to absorb transient file locks.

Copilot's findings

• Files reviewed: 3/4 changed files
• Comments generated: 0