oh-my-pi/packages/coding-agent/test/status-line-usage-refresh.test.ts

import { afterEach, beforeEach, describe, expect, it, vi } from "bun:test";
import { resetSettingsForTest, Settings } from "@oh-my-pi/pi-coding-agent/config/settings";
import { StatusLineComponent } from "@oh-my-pi/pi-coding-agent/modes/components/status-line";
import type { AgentSession } from "@oh-my-pi/pi-coding-agent/session/agent-session";

async function flushMicrotasks(): Promise<void> {
	await Promise.resolve();
	await Promise.resolve();
}

function makeSession(fetchUsageReports: (signal?: AbortSignal) => Promise<unknown>): AgentSession {
	return { fetchUsageReports } as unknown as AgentSession;
}

describe("StatusLineComponent usage refresh", () => {
	beforeEach(async () => {
		resetSettingsForTest();
		await Settings.init({ inMemory: true });
		vi.useFakeTimers();
	});

	afterEach(() => {
		vi.useRealTimers();
		resetSettingsForTest();
	});

	it("does not invoke usage fetching synchronously on the render path", async () => {
		let calls = 0;
		const component = new StatusLineComponent(
			makeSession(async () => {
				calls++;
				return [];
			}),
		);

		component.refreshUsageInBackground();
		expect(calls).toBe(0);

		vi.advanceTimersByTime(0);
		await flushMicrotasks();

		expect(calls).toBe(1);
	});

	it("passes a startup timeout signal to the background usage fetch", async () => {
		let signal: AbortSignal | undefined;
		const component = new StatusLineComponent(
			makeSession(async nextSignal => {
				signal = nextSignal;
				return [];
			}),
		);

		component.refreshUsageInBackground();
		vi.advanceTimersByTime(0);
		await flushMicrotasks();

		expect(signal).toBeInstanceOf(AbortSignal);
	});

	it("backs off after the startup timeout when usage fetching hangs", async () => {
		let calls = 0;
		const component = new StatusLineComponent(
			makeSession(() => {
				calls++;
				return Promise.withResolvers<unknown>().promise;
			}),
		);

		component.refreshUsageInBackground();
		vi.advanceTimersByTime(0);
		await flushMicrotasks();
		expect(calls).toBe(1);

		component.refreshUsageInBackground();
		expect(calls).toBe(1);

		vi.advanceTimersByTime(2_000);
		await flushMicrotasks();

		component.refreshUsageInBackground();
		vi.advanceTimersByTime(0);
		await flushMicrotasks();

		expect(calls).toBe(1);
	});
});