import {onTestFinished, vi} from 'vitest';

export const json = (status, body) => ({ok: status >= 200 && status < 300, status, json: async () => body});

/**
 * A fetch mock that answers by method and path, e.g. `'GET /api/users/me'`. The path starts at `/api/` (the base URL
 * is not set in tests) and leaves out the query. A value is an answer or `(url, init) => answer`. Any other request
 * rejects, and the test fails at its end even when the page catches the error.
 * Sets `globalThis.fetch` and returns the mock.
 */
export function fetchRoutes(routes) {
    const unknown = [];
    const mock = vi.fn(async (url, init) => {
        const key = `${init?.method ?? 'GET'} ${new URL(url, 'http://x').pathname.replace(/^.*?(?=\/api\/)/, '')}`;
        if (!(key in routes)) {
            unknown.push(key);
            throw new Error(`no route ${key}`);
        }
        const answer = routes[key];
        return typeof answer === 'function' ? answer(url, init) : answer;
    });
    globalThis.fetch = mock;
    onTestFinished(() => {
        if (unknown.length) throw new Error(`requests without a route: ${[...new Set(unknown)].join(', ')}`);
    });
    return mock;
}