fix(runtime-fallback): scope visible-assistant check to current turn and cleanup retry dedupe keys

src/hooks/runtime-fallback/message-update-handler.test.ts

@@ -0,0 +1,56 @@
+import { describe, expect, it } from "bun:test"
+import type { RuntimeFallbackPluginInput } from "./types"
+import { hasVisibleAssistantResponse } from "./visible-assistant-response"
+
+function createContext(messagesResponse: unknown): RuntimeFallbackPluginInput {
+  return {
+    client: {
+      session: {
+        abort: async () => ({}),
+        messages: async () => messagesResponse,
+        promptAsync: async () => ({}),
+      },
+      tui: {
+        showToast: async () => ({}),
+      },
+    },
+    directory: "/test/dir",
+  }
+}
+
+describe("hasVisibleAssistantResponse", () => {
+  it("#given only an old assistant reply before the latest user turn #when visibility is checked #then the stale reply is ignored", async () => {
+    // given
+    const checkVisibleResponse = hasVisibleAssistantResponse(() => undefined)
+    const ctx = createContext({
+      data: [
+        { info: { role: "user" }, parts: [{ type: "text", text: "older question" }] },
+        { info: { role: "assistant" }, parts: [{ type: "text", text: "older answer" }] },
+        { info: { role: "user" }, parts: [{ type: "text", text: "latest question" }] },
+      ],
+    })
+
+    // when
+    const result = await checkVisibleResponse(ctx, "session-old-assistant", undefined)
+
+    // then
+    expect(result).toBe(false)
+  })
+
+  it("#given an assistant reply after the latest user turn #when visibility is checked #then the current reply is treated as visible", async () => {
+    // given
+    const checkVisibleResponse = hasVisibleAssistantResponse(() => undefined)
+    const ctx = createContext({
+      data: [
+        { info: { role: "user" }, parts: [{ type: "text", text: "latest question" }] },
+        { info: { role: "assistant" }, parts: [{ type: "text", text: "visible answer" }] },
+      ],
+    })
+
+    // when
+    const result = await checkVisibleResponse(ctx, "session-visible-assistant", undefined)
+
+    // then
+    expect(result).toBe(true)
+  })
+})