Resolve turn interruption only on close cancellation

Author: benbrandt

src/CodexAcpServer.ts

@@ -1193,9 +1193,7 @@ export class CodexAcpServer {
             if (!turn) {
                 return;
             }
-            void this.interruptPromptTurn(turn, "Cancel").catch((err) => {
-                logger.error("Prompt request cancellation failed to interrupt turn", err);
-            });
+            void this.requestTurnInterrupt(turn, "Cancel");
         };
 
         if (signal.aborted) {
@@ -1223,6 +1221,20 @@ export class CodexAcpServer {
             threadId: turn.threadId,
             turnId: turn.turnId,
         });
+        try {
+            await this.requestTurnInterrupt(turn, requestName);
+        } finally {
+            this.codexAcpClient.resolveTurnInterrupted({
+                threadId: turn.threadId,
+                turnId: turn.turnId,
+            });
+        }
+    }
+
+    private async requestTurnInterrupt(
+        turn: { threadId: string, turnId: string },
+        requestName: "Cancel" | "Close",
+    ): Promise<void> {
         try {
             await this.runWithProcessCheck(() => this.codexAcpClient.turnInterrupt({
                 threadId: turn.threadId,
@@ -1234,11 +1246,6 @@ export class CodexAcpServer {
             });
         } catch (err) {
             logger.error(`${requestName} - turnInterrupt failed`, err);
-        } finally {
-            this.codexAcpClient.resolveTurnInterrupted({
-                threadId: turn.threadId,
-                turnId: turn.turnId,
-            });
         }
     }
 

src/__tests__/CodexACPAgent/CodexAcpClient.test.ts

@@ -971,8 +971,9 @@ describe('ACP server test', { timeout: 40_000 }, () => {
         const turnCompleted = deferred<TurnCompletedNotification>();
         vi.spyOn(mockFixture.getCodexAppServerClient(), "awaitTurnCompleted")
             .mockReturnValue(turnCompleted.promise);
+        const turnInterrupt = deferred<void>();
         const turnInterruptSpy = vi.spyOn(mockFixture.getCodexAcpClient(), "turnInterrupt")
-            .mockResolvedValue();
+            .mockReturnValue(turnInterrupt.promise);
         const controller = new AbortController();
 
         const promptPromise = mockFixture.getCodexAcpAgent().prompt({
@@ -992,11 +993,22 @@ describe('ACP server test', { timeout: 40_000 }, () => {
             });
         });
 
+        mockFixture.sendServerNotification({
+            method: "item/agentMessage/delta",
+            params: {
+                threadId: "session-id",
+                turnId: "turn-id",
+                itemId: "tail-item",
+                delta: "tail output",
+            },
+        });
         turnCompleted.resolve({
             threadId: "session-id",
             turn: createTurn("turn-id", "completed"),
         });
         await expect(promptPromise).resolves.toMatchObject({stopReason: "end_turn"});
+        expect(mockFixture.getAcpConnectionDump([])).toContain("tail output");
+        turnInterrupt.resolve(undefined);
     });
 
     it('interrupts a late-started turn after the ACP prompt request is cancelled', async () => {