# Java codegen: clean output directory before generating to prevent orphan accumulation (#1623)

## Summary

Add a clean step to `java/scripts/codegen/java.ts` that removes the entire
generated output directory before writing new files. This ensures that when
upstream schema types are renamed or removed, the previously-generated `.java`
files are automatically deleted rather than silently accumulating as orphans.

## Changes

- **`java/scripts/codegen/java.ts`** — At the start of `main()`, recursively
  delete `src/generated/java/com/github/copilot/generated/` and recreate the
  empty directory before invoking any generators.

- **`java/src/generated/java/`** — 204 orphan files removed (types no longer
  emitted by the current schema). These accumulated over multiple
  `@github/copilot` releases as types were renamed or removed upstream.

- **`GeneratedRpcRecordsCoverageTest.java`** — Removed test methods that
  exercised deleted generated types (`SessionWorkspaceCreateFileParams`,
  `SessionModeGetResult`, `SessionModeSetResult`, `DiscoveredMcpServerSource`,
  and 16 others).

- **`GeneratedRpcApiCoverageTest.java`** — Removed test method for the deleted
  `SessionAgentDeselectResult` type.

## Why this works going forward

The CI workflow (`java-codegen-check.yml`) runs codegen and then checks
`git status --porcelain`. Because codegen now cleans before writing, any future
orphans will appear as deletions in the diff and the check will fail —
preventing orphan accumulation without any additional workflow changes.

Fixes #1619

Author: edburns

java/scripts/codegen/java.ts

@@ -2059,6 +2059,12 @@ async function main(): Promise<void> {
     console.log("🚀 Java SDK code generator");
     console.log("============================");
 
+    // Clean the generated output directory to remove orphaned files from previous runs
+    const generatedOutputDir = path.join(REPO_ROOT, "src/generated/java/com/github/copilot/generated");
+    console.log(`🧹 Cleaning output directory: ${generatedOutputDir}`);
+    await fs.rm(generatedOutputDir, { recursive: true, force: true });
+    await fs.mkdir(generatedOutputDir, { recursive: true });
+
     const sessionEventsSchemaPath = await getSessionEventsSchemaPath();
     console.log(`📄 Session events schema: ${sessionEventsSchemaPath}`);
     const apiSchemaPath = await getApiSchemaPath();