Squashed 'third_party/pi/' content from commit d981de122

git-subtree-dir: third_party/pi
git-subtree-split: d981de1229ef899957bbe968bc8dcda02a21f477

packages/coding-agent/test/experimental-transcript-provider.test.ts

@@ -0,0 +1,108 @@
+import { replicatedState } from "@earendil-works/chord";
+import { BACKGROUND_CONTEXT } from "@earendil-works/chord/context";
+import type { AgentLane, EventListener, HarnessEvent, LaneSnapshot, WatchHandle } from "@earendil-works/pi-agent-core";
+import { describe, expect, test, vi } from "vitest";
+import type { TranscriptState } from "../src/experimental/services/transcript.ts";
+import { createTranscriptService } from "../src/experimental/services/transcript-provider.ts";
+
+function laneSnapshot(tipId: string | null = null): LaneSnapshot {
+	return {
+		lane: "main",
+		transcript: [],
+		tipId,
+		configuration: {
+			model: { provider: "test", modelId: "model" },
+			thinkingLevel: "off",
+			activeToolNames: [],
+		},
+		stats: {
+			messageCount: 0,
+			usage: {
+				input: 0,
+				output: 0,
+				cacheRead: 0,
+				cacheWrite: 0,
+				totalTokens: 0,
+				cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0, total: 0 },
+			},
+		},
+		operation: null,
+		queues: [],
+		faulted: false,
+	};
+}
+
+describe("Transcript service", () => {
+	test("publishes coherent state and rebases after navigation", async () => {
+		let listener: EventListener | undefined;
+		const replacement = laneSnapshot("replacement-tip");
+		const resnapshot = vi.fn(async () => replacement);
+		const unsubscribe = vi.fn();
+		const handle: WatchHandle<LaneSnapshot> = {
+			snapshot: laneSnapshot(),
+			start(next) {
+				listener = next;
+			},
+			resnapshot,
+			unsubscribe,
+		};
+		const lane = { watch: async () => handle } as unknown as AgentLane;
+		const runtime = createTranscriptService(lane, replicatedState);
+		const states: TranscriptState[] = [];
+		runtime.service.state.subscribe((value) => {
+			if (value.snapshot !== null) states.push(value);
+		});
+		await runtime.activate();
+
+		expect(states).toHaveLength(1);
+		expect(states[0]).toMatchObject({ snapshot: { lane: "main", operation: null }, event: null });
+		await listener?.({ type: "run_start", lane: "main", runId: "run-1", startedAt: 1 }, BACKGROUND_CONTEXT);
+		expect(states).toHaveLength(2);
+		expect(states[1]).toMatchObject({
+			snapshot: { operation: { id: "run-1" } },
+			event: { type: "run_start", runId: "run-1" },
+		});
+
+		await listener?.(
+			{
+				type: "entry_added",
+				lane: "main",
+				entry: {
+					id: "entry-1",
+					parentId: null,
+					seq: 1,
+					timestamp: 2,
+					type: "message",
+					message: { role: "user", content: "hello", timestamp: 2 },
+				},
+			},
+			BACKGROUND_CONTEXT,
+		);
+		expect(states.at(-1)).toMatchObject({
+			snapshot: { tipId: "entry-1", transcript: [{ id: "entry-1" }] },
+			event: { type: "entry_added" },
+		});
+
+		const navigation: HarnessEvent = {
+			type: "navigation_end",
+			lane: "main",
+			runId: "navigation-1",
+			status: "completed",
+			fromTipId: "entry-1",
+			tipId: "replacement-tip",
+			endedAt: 3,
+		};
+		await listener?.(navigation, BACKGROUND_CONTEXT);
+		await vi.waitFor(() => expect(states.at(-1)?.event).toBeNull());
+		expect(states.at(-2)).toMatchObject({
+			snapshot: { tipId: "entry-1" },
+			event: { type: "navigation_end" },
+		});
+		expect(states.at(-1)).toMatchObject({ snapshot: { tipId: "replacement-tip" }, event: null });
+		expect(runtime.service.state.value).toMatchObject({ snapshot: { tipId: "replacement-tip" }, event: null });
+		expect(resnapshot).toHaveBeenCalledOnce();
+
+		await runtime.dispose();
+		expect(unsubscribe).toHaveBeenCalledOnce();
+	});
+});