test(core): reproduce duplicate tool call IDs

packages/core/test/session-runner-message.test.ts

@@ -498,4 +498,60 @@ Recent work
       },
     ])
   })
+
+  test("does not lower duplicate tool call IDs from interrupted history", () => {
+    const messages = toLLMMessages(
+      [
+        SessionMessage.Assistant.make({
+          id: id("duplicate-tool-call"),
+          type: "assistant",
+          agent: "build",
+          model: { id: ModelV2.ID.make("model"), providerID: ProviderV2.ID.make("provider") },
+          content: [
+            SessionMessage.AssistantTool.make({
+              type: "tool",
+              id: "call_1",
+              name: "read",
+              state: SessionMessage.ToolStateCompleted.make({
+                status: "completed",
+                input: { path: "README.md" },
+                content: [{ type: "text", text: "done" }],
+                structured: {},
+              }),
+              time: { created, completed: created },
+            }),
+            SessionMessage.AssistantTool.make({
+              type: "tool",
+              id: "call_1",
+              name: "unknown",
+              state: SessionMessage.ToolStateError.make({
+                status: "error",
+                input: {},
+                content: [],
+                structured: {},
+                error: { type: "unknown", message: "Tool execution interrupted" },
+              }),
+              time: { created, completed: created },
+            }),
+          ],
+          time: { created, completed: created },
+        }),
+      ],
+      model,
+    )
+
+    const calls = messages.flatMap((message) =>
+      message.content.filter((part) => part.type === "tool-call" && part.id === "call_1"),
+    )
+    expect(calls).toEqual([
+      {
+        type: "tool-call",
+        id: "call_1",
+        name: "read",
+        input: { path: "README.md" },
+        providerExecuted: undefined,
+        providerMetadata: undefined,
+      },
+    ])
+  })
 })

packages/core/test/session-runner.test.ts

@@ -1769,62 +1769,6 @@ describe("SessionRunnerLLM", () => {
     }),
   )
 
-  it.effect("replays interrupted provider-local tool call IDs uniquely", () =>
-    Effect.gen(function* () {
-      yield* setup
-      const session = yield* SessionV2.Service
-      yield* session.prompt({ sessionID, prompt: Prompt.make({ text: "Echo twice" }), resume: false })
-
-      requests.length = 0
-      executions.length = 0
-      const firstGate = yield* Deferred.make<void>()
-      const secondGate = yield* Deferred.make<void>()
-      toolExecutionGate = firstGate
-      responses = [
-        [
-          LLMEvent.stepStart({ index: 0 }),
-          LLMEvent.toolCall({ id: "tool_0", name: "echo", input: { text: "first" } }),
-          LLMEvent.stepFinish({ index: 0, reason: "tool-calls" }),
-          LLMEvent.finish({ reason: "tool-calls" }),
-        ],
-        [
-          LLMEvent.stepStart({ index: 0 }),
-          LLMEvent.toolCall({ id: "tool_0", name: "echo", input: { text: "second" } }),
-          LLMEvent.stepFinish({ index: 0, reason: "tool-calls" }),
-          LLMEvent.finish({ reason: "tool-calls" }),
-        ],
-      ]
-
-      const run = yield* session.resume(sessionID).pipe(Effect.forkChild)
-      while (executions.length < 1) yield* Effect.yieldNow
-      toolExecutionGate = secondGate
-      yield* Deferred.succeed(firstGate, undefined)
-      while (executions.length < 2) yield* Effect.yieldNow
-      yield* session.interrupt(sessionID)
-      expect(yield* Fiber.await(run)).toMatchObject({ _tag: "Failure" })
-      toolExecutionGate = undefined
-
-      expect(yield* session.context(sessionID)).toMatchObject([
-        { type: "user", text: "Echo twice" },
-        { type: "assistant", content: [{ type: "tool", id: "tool_0", state: { status: "completed" } }] },
-        { type: "assistant", content: [{ type: "tool", id: "tool_0", state: { status: "error" } }] },
-      ])
-
-      requests.length = 0
-      responses = undefined
-      response = []
-      yield* session.resume(sessionID)
-
-      const callIDs = requests[0]!.messages.flatMap((message) =>
-        message.role === "assistant"
-          ? message.content.filter((part) => part.type === "tool-call").map((part) => part.id)
-          : [],
-      )
-      expect(callIDs).toHaveLength(2)
-      expect(new Set(callIDs).size).toBe(callIDs.length)
-    }),
-  )
-
   it.effect("joins concurrent resume calls into one active provider run", () =>
     Effect.gen(function* () {
       yield* setup