HttpClientMock
HttpClientMock is a library for mocking Apache HttpClient. It has an intuitive API for defining client behaviour and verifying number of made requests. It works with HttpClient 4.X and 5.X.
- Installation
- Usage
- Request matching
- Define response
- Verification
- Matching query and form parameters
- Debugging
- Example 1
- Example 2
- Release notes
Installation
HttpClientMock is available in Maven Central Repository.
- For mocking HttpClient 4.x use HttpClientMock 1.X.
- For mocking HttpClient 5.x use HttpClientMock 2.X.
Usage
Record
Working with HttpClientMock starts with defining client behaviour. Before code under tests starts HttpClientMock must know how to respond to every request.
HttpClientMock httpClientMock = new HttpClientMock();
httpClientMock.onGet("http://localhost/login")
.withParameter("user","john")
.doReturn("Ok");
httpClientMock.onPost("http://localhost/login").doReturnStatus(501);
Replay
Code under test starts and uses HttpClientMock with defined behaviour.
httpClient.execute(new HttpGet("http://localhost/login?user:john")); // returns response with body "Ok"
httpClient.execute(new HttpPost("http://localhost/login")); // returns response with status 501
Verify
When code under test finishes, HttpClientMock allows to check number of made request. It is possible to use the same set of conditions as for defining mock behaviour.
httpClientMock.verify().get("http://localhost/login").withParameter("user","john").called();
httpClientMock.verify().post("http://localhost/login").notCalled();
Request matching
HTTP method
HttpClientMock supports all Http methods.
httpClientMock.onGet().doReturn("get");
httpClientMock.onPost().doReturn("post");
httpClientMock.onPut().doReturn("put");
httpClientMock.onDelete().doReturn("delete");
httpClientMock.onOptions().doReturn("options");
httpClientMock.onHead().doReturn("head");
URL
Every onGet()
, onPost()
, .... method accept URL. It is possible to write:
httpClientMock.onGet("http://localhost/login?user=john").doReturnStatus(200);
which is equal to
httpClientMock.onGet()
.withHost("httt://locahost")
.withPath("/login")
.withParameter("user","john")
.doReturnStatus(200);
It is possible to define default host using HttpClientMock constructor, so later methods can accept relative URL-s.
HttpClientMock httpClientMock = new HttpClientMock("http://localhost");
httpClientMock.onGet("/login").doReturn("ok");
httpClientMock.onPost("/edit?user=john").doReturnStatus(200);
httpClientMock.onGet("http://www.google.com").doReturn("Google") // Absolute paths still work.
Host, path, parameters conditions
It is possible to define each part of url separately.
httpClientMock.onGet()
.withHost("httt://locahost")
.withPath("/login")
.withParameter("user","john")
.doReturnStatus(200);
Header condition
httpClientMock.onGet("http://localhost/login")
.withHeader("tracking","123")
.doReturn("ok");
Form parameters
httpClientMock.onPost("/login")
.withFormParameter("username", "John")
.withFormParameter("password", Matchers.containsString("secret"))
.doReturnStatus(200);
Body condition
httpClientMock.onGet("http://localhost/login")
.withBody("tracking",containsString("123"))
.doReturn("ok");
Custom condition
Condition fooCondition = request -> request.getUri().contains("foo");
httpClientMock.onGet("http://localhost/foo/bar")
.with(fooCondition)
.doReturn("yes");
Matchers
Every condition method accepts Hamcrest Matcher which allows to define custom conditions on requests.
httpClientMock.onGet("http://localhost")
.withPath(containsString("login"))
.withParameter("user",equalToIgnoringCase("John)")
Multiple matching rules
If request matches more then one rule, then last defined one is used.
None rule matche
If request doesn't matche any rule, HttpClientMock return response with status 404.
Define response
Response
Response with provided body and status 200.
httpClientMock.onGet("http://localhost").doReturn("my response");
Status
Response with empty body and provided status
httpClientMock.onGet("http://localhost").doReturnStatus(300);
httpClientMock.onGet("http://localhost").doReturn("Overloaded").withStatus(500);
Exception
Instead of returning response it throws defined exception.
httpClientMock.onGet("http://localhost").doThrowException(new IOException());
Custom action
Action echo = r -> {
HttpEntity entity = ((HttpEntityEnclosingRequestBase) r.getHttpRequest()).getEntity();
BasicHttpResponse response = new BasicHttpResponse(new ProtocolVersion("http", 1, 1), 200, "ok");
response.setEntity(entity);
return response;
};
httpClientMock.onGet("http://localhost").doAction(echo);
Response header
httpClientMock.onPost("/login").doReturn("foo").withHeader("tracking", "123");
Response status
httpClientMock.onPost("/login?user=bar").doReturn("Wrong user").withStatus(403);
JSON
Response with provided body, status 200 and content type "application/json"
httpClientMock.onPost("/login").doReturnJSON("{foo:1}");
XML
Response with provided body, status 200 and content type "application/xml"
httpClientMock.onPost("/login").doReturnXML("<foo>bar</foo>");
Multiple actions
It is possible to add multiple actions to one rule. Every call will use next action until last is reached.
httpClientMock.onPut("/addUser")
.doReturn("ok")
.doReturnStatus(500);
httpClientMock.execute(new HttpPut("http://localhost/addUser")); //returns "ok"
httpClientMock.execute(new HttpPut("http://localhost/addUser")); //returns status 500
httpClientMock.execute(new HttpPut("http://localhost/addUser")); //returns status 500
Verification
HttpClientMock allows to check how many calls were made. Verification supports the same set of conditions us rule defining.
httpClientMock.verify().get("http://localhost").called();
httpClientMock.verify().get("http://localhost/login")
.withParameter("user","john")
.called();
httpClientMock.verify().get("http://localhost/login")
.withParameter("user","Ben")
.notCalled();
httpClientMock.verify().delete().notCalled();
httpClientMock.verify().get().called(greaterThanOrEqualTo(1));
Matching query and form parameters
There are two methods that control HttpClientMock behaviour when request contains extra form or query parameters:
withExtraParameters
: allows request to contain extra query parameterswithoutExtraParameters
: disallows request to contain extra query parameterswithExtraFormParameters
: allows request to contain extra form parameterswithoutExtraFormParameters
: disallows request to contain extra form parameters
Examples:
httpClientMock.onPost("/login")
.withParameter("user","John")
.withoutExtraParameters()
.doReturn("ok");
Above condition will not match request http://www.example.com/login?user=John&password=secret
because
it contains extra parameter password
.
httpClientMock.onPost("/login")
.withParameter("user","John")
.withExtraParameters()
.doReturn("ok");
Above condition will match request http://www.example.com/login?user=John&password=secret
although
it contains extra parameter password
.
By default HttpClientMock matches requests with extra form and query parameters.
Debugging
HttpClientMock can help you to debug your code by displaying information which matchers matched your request.
You can use HttpClientMock#debugOn
to turn it on and HttpClientMock#debugOff
to turn it off.
Example message:
Rule 1:
MATCHES EXPECTED
true HTTP method is GET
true schema is "http"
true host is "localhost"
false path is "/login"
true port is empty
Example 1
// DEFINE BEHAVIOUR
HttpClientMock httpClientMock = new HttpClientMock("http://localhost:8080");
httpClientMock.onGet("/login?user=john").doReturnJSON("{permission:1}");
httpClientMock.onPost("/edit")
.withParameter("user","John")
.doReturn("ok")
.doReturnStatus(503);
// EXECUTION
// request to http://localhost:8080/login?user=john returns JSON {permission:1}
// first request to http://localhost:8080/edit?user=john returns message "ok"
// second request to http://localhost:8080/edit?user=john returns request with status 503
// VERIFICATION
httpClientMock.verify().get("/login?user=john").called();
httpClientMock.verify().post("/edit?user=john").called(2);
httpClientMock.verify().delete().notCalled();
Example 2
// DEFINE BEHAVIOUR
HttpClientMock httpClientMock = new HttpClientMock();
httpClientMock.onGet("http://localhost:8080/login").doReturn("Missing parameter user").withStatus(400);
httpClientMock.onGet("http://localhost:8080/login")
.withParameter("user","JJohn")
.doReturn("Wrong user name").withStatus(403);
httpClientMock.onGet("http://localhost:8080/login")
.withParameter("user","John")
.doReturn("ok");
// EXECUTION
// request to http://localhost:8080/login?user=john returns message "ok"
// VERIFICATION
httpClientMock.verify().get("/login?user=john").called();
Release notes
2.1.0
- Added method
withStatus
accepting status code and text
2.0.0
- Added support for HttpClient 5.
- Removed methods for mocking URL reference
1.9.0
- Added method
withStatus
accepting status code and text
1.8.0
- Added methods {
withExtraParameters
,withoutExtraParameters
,withExtraFormParameters
,withoutExtraFormParameters
} to better control form and query parameters matching. WARNING Breaking changes: Since this version by default HttpClientMock matches requests with extra form and query parameters.
1.7.0
- Added methods (
withFormParameter
,withFormParameters
) for matching form parameters (URL encode parameters). - Added action (
doReturnFormParams
) which return response with body containing provided form parameters.
1.6.0
- Added possibility to set response
Content-Type
. - Fixed wrong
Contet-Type
in methods 'doReturnXML',doReturnJSON
1.5.0
- Added possibility to add cookies to the response.