fix(resume): harden transcript backfill (#1082)

src/tests/cli/prepareMessageHistory.test.ts

@@ -0,0 +1,105 @@
+import { describe, expect, test } from "bun:test";
+import type { Message } from "@letta-ai/letta-client/resources/agents/messages";
+import { prepareMessageHistory } from "../../agent/check-approval";
+
+function msg(
+  type: string,
+  id: string,
+  dateMs: number,
+  extra?: Record<string, unknown>,
+): Message {
+  return {
+    id,
+    message_type: type,
+    date: new Date(dateMs).toISOString(),
+    ...(extra ?? {}),
+  } as unknown as Message;
+}
+
+describe("prepareMessageHistory", () => {
+  test("primaryOnly returns only primary message types", () => {
+    const base = 1_700_000_000_000;
+    const messages: Message[] = [
+      msg("user_message", "u1", base + 1),
+      msg("tool_call_message", "tc1", base + 2),
+      msg("approval_request_message", "ar1", base + 3),
+      msg("tool_return_message", "tr1", base + 4),
+      msg("assistant_message", "a1", base + 5),
+      msg("reasoning_message", "r1", base + 6),
+      msg("approval_response_message", "ap1", base + 7),
+      msg("event_message", "e1", base + 8),
+      msg("summary_message", "s1", base + 9),
+    ];
+
+    const out = prepareMessageHistory(messages, { primaryOnly: true });
+    expect(out.map((m) => m.message_type)).toEqual([
+      "user_message",
+      "assistant_message",
+      "event_message",
+      "summary_message",
+    ]);
+  });
+
+  test("primaryOnly includes most recent assistant even if last N primary messages lack it", () => {
+    const base = 1_700_000_000_000;
+    const messages: Message[] = [];
+
+    // An older assistant message, then many user/event messages.
+    messages.push(msg("assistant_message", "a1", base + 1));
+    for (let i = 0; i < 30; i += 1) {
+      messages.push(msg("user_message", `u${i}`, base + 10 + i));
+    }
+
+    const out = prepareMessageHistory(messages, { primaryOnly: true });
+    expect(out.some((m) => m.message_type === "assistant_message")).toBe(true);
+    expect(
+      out.every((m) =>
+        [
+          "user_message",
+          "assistant_message",
+          "event_message",
+          "summary_message",
+        ].includes(m.message_type as string),
+      ),
+    ).toBe(true);
+  });
+
+  test("primaryOnly falls back to reasoning when no primary messages exist", () => {
+    const base = 1_700_000_000_000;
+    const messages: Message[] = [
+      msg("tool_return_message", "tr1", base + 1),
+      msg("reasoning_message", "r1", base + 2),
+      msg("tool_return_message", "tr2", base + 3),
+      msg("reasoning_message", "r2", base + 4),
+    ];
+
+    const out = prepareMessageHistory(messages, { primaryOnly: true });
+    expect(out.map((m) => m.message_type)).toEqual([
+      "reasoning_message",
+      "reasoning_message",
+    ]);
+  });
+
+  test("primaryOnly returns [] when no primary or reasoning messages exist", () => {
+    const base = 1_700_000_000_000;
+    const messages: Message[] = [
+      msg("tool_return_message", "tr1", base + 1),
+      msg("approval_request_message", "ar1", base + 2),
+      msg("approval_response_message", "ap1", base + 3),
+    ];
+
+    const out = prepareMessageHistory(messages, { primaryOnly: true });
+    expect(out).toEqual([]);
+  });
+
+  test("non-primaryOnly skips orphaned leading tool_return_message", () => {
+    const base = 1_700_000_000_000;
+    const messages: Message[] = [
+      msg("tool_return_message", "tr1", base + 1),
+      msg("assistant_message", "a1", base + 2),
+    ];
+
+    const out = prepareMessageHistory(messages);
+    expect(out[0]?.message_type).toBe("assistant_message");
+  });
+});