fix: recover session submissions and failed turn settlement

tests/turn-recovery.test.ts

@@ -0,0 +1,90 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+import type { Agent, AgentMessage } from "@earendil-works/pi-agent-core";
+import type { ChatStore } from "../src/core/ports.ts";
+import { runPiTurn } from "../src/server/pi/ui-stream.ts";
+import { persistTurn } from "../src/server/turn-service.ts";
+
+/** No engine or network: exercise the runner's awaited listener seam. */
+function agentEndingWith(loopFailure?: Error): Agent {
+	const listeners: Array<(event: never) => unknown> = [];
+	return {
+		state: { messages: [] },
+		subscribe(listener: (event: never) => unknown) { listeners.push(listener); return () => {}; },
+		async continue() {
+			await Promise.resolve(); // let the view subscribe before the terminal
+			if (loopFailure) throw loopFailure;
+			for (const listener of listeners) await listener({ type: "agent_end", messages: [] } as never);
+		},
+		abort() {},
+	} as unknown as Agent;
+}
+
+function wireFrames(wire: string): string[] {
+	return wire.split("\n\n").filter(Boolean).map(frame => frame.slice("data: ".length));
+}
+
+describe("turn settlement recovery", () => {
+	it("reports a failed canonical save before DONE and cleans up before reporting", async () => {
+		const order: string[] = [];
+		const handle = runPiTurn({
+			agent: agentEndingWith(),
+			onFinish() { order.push("save"); throw new Error("synthetic disk failure"); },
+			onSettleFailure() { order.push("cleanup"); },
+			onSettleError() { order.push("report"); return "The reply could not be saved."; },
+		});
+		const frames = wireFrames(await new Response(handle.subscribe()).text());
+		assert.deepEqual(order, ["save", "cleanup", "report"]);
+		assert.equal(frames.at(-1), "[DONE]");
+		assert.equal(frames.filter(f => f.includes('"type":"error"')).length, 1);
+		assert.ok(frames.at(-2)?.includes("The reply could not be saved."));
+	});
+
+	it("still reports settlement failure when cleanup itself throws", async () => {
+		const handle = runPiTurn({
+			agent: agentEndingWith(),
+			onFinish() { throw new Error("synthetic save failure"); },
+			onSettleFailure() { throw new Error("synthetic cleanup failure"); },
+			onSettleError: () => "The reply could not be saved.",
+		});
+		const frames = wireFrames(await new Response(handle.subscribe()).text());
+		assert.equal(frames.at(-1), "[DONE]");
+		assert.equal(frames.filter(f => f.includes('"type":"error"')).length, 1);
+	});
+
+	it("does not replace an already reported loop failure with a second settlement error", async () => {
+		let cleanups = 0;
+		const handle = runPiTurn({
+			agent: agentEndingWith(new Error("synthetic loop failure")),
+			onError: () => "An error occurred.",
+			onFinish() { throw new Error("synthetic save failure"); },
+			onSettleFailure(error, reportedErrorText) {
+				cleanups++;
+				assert.match(String(error), /synthetic save failure/);
+				assert.equal(reportedErrorText, "An error occurred.");
+			},
+		});
+		const frames = wireFrames(await new Response(handle.subscribe()).text());
+		assert.equal(cleanups, 1);
+		assert.equal(frames.filter(f => f.includes('"type":"error"')).length, 1);
+		assert.equal(frames.at(-1), "[DONE]");
+	});
+
+	it("a healthy terminal follows persistence and emits no error", async () => {
+		let saves = 0;
+		const handle = runPiTurn({ agent: agentEndingWith(), onFinish() { saves++; } });
+		const frames = wireFrames(await new Response(handle.subscribe()).text());
+		assert.equal(saves, 1);
+		assert.equal(frames.at(-1), "[DONE]");
+		assert.equal(frames.some(f => f.includes('"type":"error"')), false);
+	});
+
+	it("does not contain a canonical write failure as an empty successful persist", () => {
+		const store = {
+			getChat: () => ({ messages: [] }),
+			saveMessages() { throw new Error("synthetic disk failure"); },
+		} as unknown as ChatStore;
+		const message = { role: "assistant", content: [{ type: "text", text: "Synthetic reply" }], stopReason: "stop", timestamp: 1 } as AgentMessage;
+		assert.throws(() => persistTurn(store, "fixture", 0, [message], false), /The reply could not be saved\./);
+	});
+});