TODO API Client Kata for Kotlin Developers. The main goal is to practice integration testing using MockWebServer
Switch branches/tags
Nothing to show
Clone or download
Serchinastico Merge pull request #4 from Karumi/Add-contributors-section
Add contributors section to the README
Latest commit 6f062a9 Feb 28, 2018

Karumi logo KataTODOApiClient for Kotlin Build Status

  • We are here to practice integration testsing using HTTP stubbing.
  • We are going to use MockWebServer to simulate a HTTP server.
  • We are going to use JUnit to perform assertions.
  • We are going to practice pair programming.

Getting started

This repository contains an API client to interact with a remote service we can use to implement a TODO application.

This API Client is based on one class with name TodoApiClient containing some methods to interact with the API. Using this class we can get all the tasks we have created before, get a task using the task id, add a new task, update a task or delete an already created task.

The API client has been implemented using a networking framework named Retrofit. Review the project documentation if needed.


Your task as a Kotlin Developer is to write all the integration tests needed to check if the API Client is working as expected.

This repository is ready to build the application, pass the checkstyle and your tests in Travis-CI environments.

Our recommendation for this exercise is:

  • Before starting

    1. Fork this repository.
    2. Checkout kata-todo-api-client branch.
    3. Execute the repository playground and make yourself familiar with the code.
    4. Execute TodoApiClientTest and watch the only test it contains pass.
  • To help you get started, these are some tests already written at TodoApiClientTest class. Review it carefully before to start writing your own tests. Here you have the description of some tests you can write to start working on this Kata:

    1. Test that the Accept and ContentType headers are sent.
    2. Test that the list of TaskDto instances obtained invoking the getter method of the property allTasks contains the expected values.
    3. Test that the request is sent to the correct path using the correct HTTP method.
    4. Test that adding a task the body sent to the server is the correct one.


  • If you get stuck, master branch contains all the tests already solved.

  • You will find some utilities to help you test the APIClient easily in: MockWebServerTest and the test resources directory.

Extra Tasks

If you've covered all the application functionality using integration tests you can continue with some extra tasks:

  • Replace some integration tests we have created with unit tests. A starting point could be the DefaultHeadersInterceptor class.
  • Create your own API client to consume one of the services described in this web:


There are some links which can be useful to finish these tasks:


Thank you all for your work!

Igor Ganapolsky


Copyright 2017 Karumi

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.