import { test } from 'node:test';
import assert from 'node:assert/strict';
import { apiError } from './net.ts';

// Minimal Response-shaped stubs; apiError only touches `.json`.
const resp = (json: () => Promise<unknown>) => ({ json }) as unknown as Response;

test('apiError returns the server error string when present', async () => {
  assert.equal(await apiError(resp(async () => ({ error: 'This promo code has expired' }))), 'This promo code has expired');
});

test('apiError falls back when the body has no error field', async () => {
  assert.equal(await apiError(resp(async () => ({ ok: true })), 'nope'), 'nope');
});

test('apiError falls back on a non-JSON / throwing body', async () => {
  assert.equal(await apiError(resp(async () => { throw new Error('not json'); })), 'Request failed');
});

test('apiError falls back on a null/!response', async () => {
  assert.equal(await apiError(null), 'Request failed');
  assert.equal(await apiError(undefined, 'x'), 'x');
});

test('apiError ignores a non-string error field', async () => {
  assert.equal(await apiError(resp(async () => ({ error: { nested: true } })), 'fb'), 'fb');
});