fix(compaction): forward abortSignal through delegateCompactionToRuntime bridge

xin · xin · commit ec059ec320d7 · 2026-06-15T18:13:03.000+08:00
When a user presses the stop button during auto-compaction, the abort signal cancels the wait but the compaction LLM call continues in-flight and writes its result to the session transcript. This causes model confusion as the model receives only a compaction summary instead of the full context. The bridge gap: delegateCompactionToRuntime forwarded sessionId, sessionFile, tokenBudget, and other params, but not abortSignal. The runtime already accepts this field in CompactEmbeddedAgentSessionParams, but it was never populated by the delegate. Fix: forward params.abortSignal so the runtime can properly abort compaction when the stop button or safety timeout fires. Closes #89868
diff --git a/src/context-engine/context-engine.test.ts b/src/context-engine/context-engine.test.ts
@@ -434,6 +434,8 @@ describe("Engine contract tests", () => {
     expect(compactRuntimeParams.tokenBudget).toBe(4096);
     expect(compactRuntimeParams.currentTokenCount).toBe(12345);
     expect(compactRuntimeParams.workspaceDir).toBe("/tmp/workspace");
+    // abortSignal should be undefined when not passed
+    expect(compactRuntimeParams.abortSignal).toBeUndefined();
     expect(result).toEqual({
       ok: true,
       compacted: false,
@@ -448,6 +450,25 @@ describe("Engine contract tests", () => {
     });
   });
 
+  it("forwards abortSignal to the compaction runtime bridge", async () => {
+    const compactRuntimeSpy = installCompactRuntimeSpy();
+    const controller = new AbortController();
+    const abortSignal = controller.signal;
+
+    await delegateCompactionToRuntime({
+      sessionId: "s3",
+      sessionFile: "/tmp/session.json",
+      tokenBudget: 4096,
+      abortSignal,
+      runtimeContext: { workspaceDir: "/tmp/workspace" },
+    });
+
+    const compactRuntimeParams = requireCompactRuntimeParams(0);
+    // abortSignal must be forwarded so the runtime can abort compaction
+    // when the stop button is pressed during overflow auto-compaction
+    expect(compactRuntimeParams.abortSignal).toBe(abortSignal);
+  });
+
   it("builds a normalized memory system prompt addition from the active memory prompt path", () => {
     registerMemoryPromptSection(({ citationsMode }) => [
       "## Memory Recall",
diff --git a/src/context-engine/delegate.ts b/src/context-engine/delegate.ts
@@ -60,6 +60,7 @@ export async function delegateCompactionToRuntime(
     ...(currentTokenCount !== undefined ? { currentTokenCount } : {}),
     force: params.force,
     customInstructions: params.customInstructions,
+    abortSignal: params.abortSignal,
     workspaceDir:
       typeof runtimeContext.workspaceDir === "string" ? runtimeContext.workspaceDir : process.cwd(),
   });
