注意：我使用（）代替尖括号<>作为数据类型，因为找不到在论坛上使用它们的方法。
我有一个使用Retofit2和RxJava2从GitHub Api获取数据的MVP android应用程序。代码工作正常，我能够恢复一个Observable（Response（List（Headers））），其中Response来自Retrofit2，而Headers形式为OkHttp3。
但是当涉及到单元测试时，我遇到了一个问题：我无法模拟Response（List（Headers））。 Retrofit2 Response类具有私有构造函数，因此我无法创建该实例。 然后，我尝试使用OkHttp MockWebServer并具有MockResponse（List（Headers））的想法。尽管我可以将Headers设置为MockResponse实例，但是却无法获得MockResponse（List（Headers））
我的服务：
@GET("users/{username}/repos")
Observable<Response<List<Headers>>> checkReposPerUser(@Path("username") String owner,
@Query("access_token") String accessTokenString,
@Query("token_type") String accessTokenTypeString,
@Query("per_page") String perPageValue);
我的主持人：
@Override
public void checkRepoPerUser(String owner) {
//recovering access token data from Shared Preferences;
String accessTokenString = repository.getAccessTokenString();
String accessTokenTypeString = repository.getAccessTokenType();
//Asking for a list of repositories with 1 repository per page.
//This let us know how many repositories we found and also to deal with error response code
Disposable disposable = repository.checkReposPerUser(owner, accessTokenString, accessTokenTypeString, "1")
.subscribeOn(ioScheduler)
.observeOn(uiScheduler)
.subscribe(this::handleReturnedHeaderData, this::handleHeaderError);
disposeBag.add(disposable);
}
@VisibleForTesting
public void handleReturnedHeaderData(Response<List<Headers>> response) {
//getting value 'Link' from response headers in order to count the repositories
String link = response.headers().get("Link");
String message = response.message();
//checking GitHub API requests limit
String limit = response.headers().get("X-RateLimit-Limit");
Log.d(TAG, "Limit requests: " + limit);
String limitRemaining = response.headers().get("X-RateLimit-Remaining");
Log.d(TAG, "Limit requests remaining: " + limitRemaining);
//getting http response code
int code = response.code();
switch (code){
case 404:
if(message.equalsIgnoreCase("not found")){ //User not exists
view.showUserNotFoundMessage();
}else{
view.showErrorMessage(message);
}
break;
case 403:
//GitHub API requests limit reached
//Instead of showing an error, we start the login process,
// store another access token in shared Preferences and resend the same request that failed before
view.startLogin();
break;
case 200:
if(link == null){ //Link value is not present into the header, it means there's 0 or 1 repo
Log.d(TAG, "Total repos for current user is 0 or 1.");
//get the repository
searchRepo(view.getOwner()); //Starting looking for data
}else if( link != null){
//get last page number: considering that we requested all the repos paginated with
//only 1 repo per page, the last page number is equal to the total number of repos
String totalRepoString = link.substring(link.lastIndexOf("&page=") + 6, link.lastIndexOf(">"));
Log.d(TAG, "Total repos for current user are " + totalRepoString);
// TODO once we know how many repositories we have, we can decide how many calls to do (total repositories/100 rounded up )
//get the repositories
searchRepo(view.getOwner()); //Starting 3 looking for data
}
break;
default:
searchRepo(view.getOwner()); //Starting 3 looking for data
break;
}
}
现在，我要对handleReturnedHeaderData（Response（List（Headers））response）进行单元测试。这是Test类：
public class RepositoriesPresenterTest {
private static final Repo REPO1 = new Repo();
private static final Repo REPO2 = new Repo();
private static final Repo REPO3 = new Repo();
private static final List<Repo> NO_REPOS = Collections.emptyList();
private static final List<Repo> THREE_REPOS = Arrays.asList(REPO1, REPO2, REPO3);
public static final String OWNER = "owner";
public static final String ACCESS_TOKEN_STRING = "access_token_string";
public static final String ACCESS_TOKEN_TYPE = "access_token_type";
public static final String PER_PAGE_VALUE = "per_page_value";
@Parameterized.Parameters
public static Object[] data() {
return new Object[] {NO_REPOS, THREE_REPOS};
}
@Parameterized.Parameter
public List<Repo> repos;
@Rule
public MockitoRule mockitoRule = MockitoJUnit.rule();
@Mock private GitHubChallengeRepository repositoryMock;
@Mock private RepositoriesContract.View viewMock;
@Mock private Response<List<Headers>> responseListHeaders;
private TestScheduler testScheduler;
private RepositoriesPresenter SUT; //System Under Test
@Before public void setUp() {
testScheduler = new TestScheduler();
SUT = new RepositoriesPresenter(repositoryMock, viewMock, testScheduler, testScheduler);
}
}
进入我尝试过的RepositoriesPresenterTest类：
@Test public void repoPresenter_CheckRepoPerUser_responseHeadersListExpected() throws Exception {
// Mock a response with status 200 and some Headers
MockResponse mockResponse = new MockResponse()
.setResponseCode(200)
.setBody("{}")
.setHeader("Status", "status_value")
.setHeader("X-RateLimit-Limit", "60")
.setHeader("X-RateLimit-Remaining", "57");
List<Headers> headersList = Arrays.asList(mockResponse.getHeaders());
// Given
given(repositoryMock.getAccessTokenString()).willReturn(ACCESS_TOKEN_STRING);
given(repositoryMock.getAccessTokenType()).willReturn(ACCESS_TOKEN_TYPE);
given(repositoryMock.checkReposPerUser(
OWNER,
ACCESS_TOKEN_STRING,
ACCESS_TOKEN_TYPE,
PER_PAGE_VALUE)).willReturn((Observable<Response<List<Headers>>>) Observable.just(headersList));
// When
SUT.checkRepoPerUser(OWNER);
testScheduler.triggerActions();
// Then
then(viewMock).should().getOwner();
}
但是它无法编译，因为我无法将 Observable.just（headersList）强制转换为 一个 Observable（Response（List（Headers）））。
之后，我尝试使用MockWebServer模拟连接（即使我认为测试不必要）：
@Test
public void repoPresenter_CheckRepoPerUser_responseHeadersListExpected() throws InterruptedException, IOException {
MockWebServer mockWebServer = new MockWebServer();
TestObserver testObserver = new TestObserver<Response<List<Headers>>>();
String path = "\"users/{username}/repos\"";
// Mock a response with status 200 and some Headers
MockResponse mockResponse = new MockResponse()
.setResponseCode(200)
.setBody("{}")
.setHeader("Status", "status_value")
.setHeader("X-RateLimit-Limit", "60")
.setHeader("X-RateLimit-Remaining", "57");
// Enqueue request
mockWebServer.enqueue(mockResponse);
// Call the API
repositoryMock.checkReposPerUser(
OWNER,
ACCESS_TOKEN_STRING,
ACCESS_TOKEN_TYPE,
PER_PAGE_VALUE).subscribe((Consumer<? super Response<List<Headers>>>) Observable.just(Arrays.asList(mockResponse.getHeaders()));
testScheduler.triggerActions();
testObserver.awaitTerminalEvent(2, TimeUnit.SECONDS);
// No errors
testObserver.assertNoErrors();
// Make sure we made the request to the required path
assertEquals("60", mockResponse.getHeaders().get("X-RateLimit-Limit"));
// When
SUT.checkRepoPerUser(OWNER);
testScheduler.triggerActions();
// Then
then(viewMock).should().getOwner();
// Shut down the server. Instances cannot be reused.
mockWebServer.shutdown();
}
但是我收到了ClassCastException：
java.lang.ClassCastException: io.reactivex.internal.operators.observable.ObservableJust cannot be cast to io.reactivex.functions.Consumer
是否有任何可行的方法来模拟Response（List（Headers）），还是我应该开始考虑改变从端点获取数据的方式？
答案 0 :(得分：1)
使用改造自己的Response对象，创建模拟响应非常简单。正如您所说的，构造函数是私有的，但是您可以使用静态方法创建成功的响应：
Response<List<Headers>> response = Response.success(headersList);
例如，如果您想创建一个失败并返回401错误的响应，则可以这样操作：
ResponseBody theBody = ResponseBody.create(MediaType.parse("text/html"), "");
Response<List<Headers>> response = Response.error(401, theBody);