{"id":1769,"date":"2012-09-25T19:00:00","date_gmt":"2012-09-25T19:00:00","guid":{"rendered":"http:\/\/www.javacodegeeks.com\/2012\/10\/testing-client-side-of-restful-services.html"},"modified":"2012-10-22T06:43:59","modified_gmt":"2012-10-22T06:43:59","slug":"testing-client-side-of-restful-services","status":"publish","type":"post","link":"https:\/\/www.javacodegeeks.com\/2012\/09\/testing-client-side-of-restful-services.html","title":{"rendered":"Testing client side of RESTful services"},"content":{"rendered":"
Develop an application that uses RESTful web API<\/i> may imply developing server and client side. Writing integration tests for server side can be as easy as using Arquillian<\/i> to start up server and REST-assured<\/i> to test that the services works as expected. The problem is how to test the client side. In this post we are going to see how to test the client side apart from using mocks.<\/p>\n

As a brief description, to test client part, what we need is a local server which can return recorded JSON<\/i> responses. The rest-client-driver<\/strong> is a library which simulates a RESTful<\/i> service. You can set expectations on the HTTP<\/i> requests you want to receive during a test. So it is exactly what we need for our java client side. Note that this project is really helpful to write tests when we are developing RESTful<\/i> web clients for connecting to services developed by third parties like Flickr Rest API<\/i>, Jira Rest API<\/i>, Github<\/i> …
\nFirst thing to do is adding rest-client-driver<\/strong> dependency:<\/p>\n

 <dependency>\r\n     <groupId>com.github.rest-driver<groupId>\r\n     <artifactId>rest-client-driver<artifactId>\r\n     <version>1.1.27<version>\r\n     <scope>test<scope>\r\n <dependency>\r\n<\/pre>\n
Next step we are going to create a very simple          Jersey<\/strong>         application which simply invokes a get method to required          URI.<\/i>
 
<\/div> <\/div><\/p>\n
 public class GithubClient {\r\n \r\n  private static final int HTTP_STATUS_CODE_OK = 200;\r\n \r\n  private String githubBaseUri;\r\n \r\n  public GithubClient(String githubBaseUri) {\r\n   this.githubBaseUri = githubBaseUri;\r\n  }\r\n \r\n  public String invokeGetMethod(String resourceName) {\r\n \r\n   Client client = Client.create();\r\n   WebResource webResource = client.resource(githubBaseUri+resourceName);\r\n   ClientResponse response = webResource.type('applicationjson')\r\n     .accept('applicationjson').get(ClientResponse.class);\r\n   int statusCode = response.getStatus();\r\n \r\n   if(statusCode != HTTP_STATUS_CODE_OK) {\r\n    throw new IllegalStateException('Error code '+statusCode);\r\n   }\r\n \r\n   return response.getEntity(String.class);\r\n  }\r\n \r\n }\r\n<\/pre>\n
And now we want to test that           invokeGetMethod<\/i> really gets the required resource. Let’s suppose that this method in production code will be responsible of getting all issues name from a project registered on           github<\/i>.          <\/p>\n
Now we can start to write the test:<\/p>\n
 @Rule\r\n public ClientDriverRule driver = new ClientDriverRule();\r\n \r\n @Test\r\n public void issues_from_project_should_be_retrieved() {\r\n \r\n  driver.addExpectation(\r\n    onRequestTo('reposlordofthejarsnosqlunitissues').\r\n      withMethod(Method.GET), giveResponse(GET_RESPONSE));\r\n \r\n  GithubClient githubClient = new GithubClient(driver.getBaseUrl());\r\n \r\n  String issues = githubClient.invokeGetMethod('reposlordofthejarsnosqlunitissues');\r\n  assertThat(issues, is(GET_RESPONSE)); \r\n \r\n }\r\n<\/pre>\n