Skip to main content

Assertions

Mockly integrates naturally with FluentAssertions through the FluentAssertions.Mockly extension packages. These packages provide a set of intention-revealing extension methods to verify that your system under test interacted with the HTTP mocks as expected.

Installation​

Depending on which version of FluentAssertions you are using, install the corresponding Mockly assertion package:

For FluentAssertions v8.x​

dotnet add package FluentAssertions.Mockly.v8

For FluentAssertions v7.x​

dotnet add package FluentAssertions.Mockly.v7

HttpMock Assertions​

You can perform high-level assertions on the HttpMock instance itself to ensure all configured mocks were utilized.

using var mock = new HttpMock();
mock.ForGet("/api/users").RespondsWithStatus(HttpStatusCode.OK);

// ... perform actions ...

// Verify that all configured mocks were called at least once
mock.Should().HaveAllRequestsCalled();

// Verify that mocks were called in a specific order
var mock1 = mock.ForGet("/api/first").RespondsWithStatus(HttpStatusCode.OK);
var mock2 = mock.ForGet("/api/second").RespondsWithStatus(HttpStatusCode.OK);

mock.Should().HaveCalledInOrder(mock1, mock2);

Unexpected Requests​

You can verify that no unexpected calls were made to the mock:

mock.Requests.Should().NotContainUnexpectedCalls();

Setup Assertions​

If you keep a reference to a mock setup, you can assert on it directly.

var userMock = mock.ForGet("/api/users/*").RespondsWithStatus(HttpStatusCode.OK);

// ... perform actions ...

userMock.Should().HaveBeenCalled();
userMock.Should().HaveBeenCalled(Because.Of("the user list should be refreshed"));

Request Collection Assertions​

When using a RequestCollection to capture requests, you can use specialized assertions to inspect the captured data.

var captured = new RequestCollection();
mock.ForPost("/api/data").CollectingRequestsIn(captured).RespondsWithStatus(HttpStatusCode.OK);

// ... perform actions ...

// Check if any requests were captured at all
captured.Should().NotBeEmpty();
captured.Should().HaveCount(2);

// Assert on the presence of specific requests using URL patterns
captured.Should().ContainRequestFor("/api/data");
captured.Should().NotContainRequestFor("/api/other");

Chaining Assertions​

The ContainRequestFor assertion allows you to chain further checks on the matched request using the Which property.

captured.Should().ContainRequestFor("/api/data")
    .Which.HasHeader("X-Custom-Header", "ExpectedValue")
    .And.WithBody("*part-of-body*")
    .And.WithBearerToken();

Available Chained Assertions​

On the result of ContainRequestFor(...).Which, you can use:

  • HasHeader(name, [value]): Verifies the presence and optionally the value of a header.
  • WithBody(pattern): Verifies the request body matches a string or wildcard pattern.
  • WithBearerToken(): Verifies that a Bearer token is present in the Authorization header.
  • WithQuery(query): Verifies the request query string.

Body Assertions on Captured Requests​

Use these specialized assertions to verify the JSON body of captured requests:

// Assert JSON-equivalence using a JSON string (ignores formatting/ordering)
mock.Requests.Should().ContainRequest()
    .WithBodyMatchingJson("{ \"id\": 1, \"name\": \"John\" }");

// Assert the body deserializes and is equivalent to an object graph
var expected = new { id = 1, name = "John" };
mock.Requests.Should().ContainRequest()
    .WithBodyEquivalentTo(expected);

// Assert the body has specific properties (deserialized as a dictionary)
var expectedProps = new Dictionary<string, string>
{
    ["id"] = "1",
    ["name"] = "John"
};
mock.Requests.Should().ContainRequest()
    .WithBodyHavingPropertiesOf(expectedProps);
info

These assertions require the request body to be available in memory. If you disabled HttpMock.PrefetchBody, these assertions will fail as RequestInfo.Body will be null.

Individual Request Assertions​

You can also assert on individual CapturedRequest objects.

var request = captured.First();

request.Should().BeExpected();
request.Should().NotBeUnexpected();