Testing

Testing

package:wordpress_client/testing.dart provides a Dio adapter that serves canned responses, so code that uses the client can be tested without a live site or real network.

import 'package:dio/dio.dart';
import 'package:wordpress_client/testing.dart';
import 'package:wordpress_client/wordpress_client.dart';

Build a client on the mock

final adapter = MockWordpressAdapter();

final client = WordpressClient.fromDioInstance(
  baseUrl: Uri.parse('https://example.com/wp-json/wp/v2'),
  instance: Dio()..httpClientAdapter = adapter,
  bootstrapper: (b) => b.build(),                // add auth, retries, cache, ... as in production
);

Script responses

Routes match on HTTP method and path (a String is matched as a path suffix; pass a RegExp for patterns). The newest route wins.

adapter
  ..reply('GET', '/posts', MockResponse.paged(
    [{'id': 1, 'title': {'rendered': 'Hello'}}],
    total: 1,
    totalPages: 1,
  ))
  ..reply('POST', '/posts', MockResponse.wpError(
    statusCode: 403,
    code: 'rest_cannot_create',
    message: 'Sorry, you are not allowed to create posts.',
  ))
  ..reply('GET', '/pages', const MockResponse(statusCode: 200, body: []));

MockResponse	Result
MockResponse(statusCode:, body:, headers:, delay:)	Any response. body can be a map, list or string
MockResponse.paged(items, total:, totalPages:)	List with X-WP-Total and X-WP-TotalPages
MockResponse.wpError(statusCode:, code:, message:)	A WordPress error body
MockResponse.connectionError()	A transport failure (NetworkFailure)
MockResponse.timeout()	A timeout (NetworkFailure(kind: timeout))

Dynamic and sequential answers:

adapter.on('GET', RegExp(r'/posts/\d+$'), (req) {
  final id = int.parse(req.path.split('/').last);
  return MockResponse(body: {'id': id, 'title': {'rendered': 'Post $id'}});
});

adapter.replySequence('GET', '/pages', [
  MockResponse.timeout(),                       // first call fails
  const MockResponse(body: []),                 // then succeeds (the last entry repeats)
]);

MockWordpressAdapter(strict: true) throws a StateError for a request without a route; the default answers 404 rest_no_route.

Assert on what was sent

await client.posts.create(CreatePostRequest(title: 'Hi'));

expect(adapter.callCount(method: 'POST', path: '/posts'), 1);
expect(adapter.lastRequest!.body.toString(), contains('Hi'));
expect(adapter.lastRequest!.headers['Authorization'], isNotNull);   // when a default authorization is set
expect(adapter.requests.map((r) => r.uri.path), contains('/wp-json/wp/v2/posts'));
adapter.clearRequests();

RecordedRequest has method, uri, path, headers, body (its type depends on the request: a map, a JSON string, form data).

Test retries without waiting

final client = WordpressClient.fromDioInstance(
  baseUrl: baseUrl,
  instance: Dio()..httpClientAdapter = adapter,
  bootstrapper: (b) => b
      .withRetryPolicy(RetryPolicy(maxAttempts: 3, sleep: (_) async {}))   // no real delay
      .build(),
);

adapter.replySequence('GET', '/posts', [
  MockResponse.wpError(statusCode: 503, code: 'unavailable'),
  MockResponse.paged([], total: 0, totalPages: 0),
]);

final r = await client.posts.list(ListPostRequest());
expect(r.isSuccessful, isTrue);
expect(r.extra?[WordpressRequest.metaAttempts], 2);

Test your own code

Inject the client (or a factory) into your repositories and pass this one in tests. Because the mock goes through the real pipeline, middlewares, caching, auth headers and typed failures behave as in production.