HTTP content matchers

Describes the JSON matchers that this package adds to Mockolate's It.IsHttpContent().

Matcher	Summary
WithJsonMatching	the JSON body matches the expected object
WithJson	the JSON body is equivalent to the expected JSON string
IgnoringAdditionalProperties	whether additional properties in the JSON body are ignored
IgnoringAdditionalArrayElements	whether additional array elements in the JSON body are ignored

.NET 8 or later

The HTTP content matchers require .NET 8 or later.

The matchers are in the namespace Mockolate.Web. They are argument matchers, not expectations: use them in setups or verifications of a mocked HttpClient to match the JSON body of a request.

JSON body

WithJsonMatching compares the body with an object, and WithJson with a JSON string, ignoring differences in formatting and property order:

HttpClient httpClient = HttpClient.CreateMock();
httpClient.Mock.Setup
    .PostAsync(It.IsAny<Uri>(), It.IsHttpContent().WithJsonMatching(new { title = "Let It Be", year = 1970 }))
    .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.Created));

httpClient.Mock.Setup
    .PostAsync(It.IsAny<Uri>(), It.IsHttpContent().WithJson("{\"year\": 1965, \"title\": \"Yesterday\"}"))
    .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.Created));

Trimming and Native AOT

WithJsonMatching serializes the expected value by reflection, which is switched off when publishing with trimming or Native AOT enabled, so use WithJson with the expected JSON as a string there.

Additional properties and elements

WithJson requires the body to be equivalent to the expected JSON: additional properties of objects and additional elements at the end of arrays do not match. WithJsonMatching ignores both by default.

Change this on either matcher with IgnoringAdditionalProperties and IgnoringAdditionalArrayElements:

httpClient.Mock.Setup
    .PostAsync(It.IsAny<Uri>(), It.IsHttpContent()
        .WithJson("{\"title\": \"Let It Be\", \"tracks\": [\"Two of Us\"]}")
        .IgnoringAdditionalProperties()
        .IgnoringAdditionalArrayElements())
    .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.Created));

httpClient.Mock.Setup
    .PostAsync(It.IsAny<Uri>(), It.IsHttpContent()
        .WithJsonMatching(new { title = "Let It Be", year = 1970 })
        .IgnoringAdditionalProperties(false))
    .ReturnsAsync(new HttpResponseMessage(HttpStatusCode.Created));

No match returns the default response

When the body does not match, the setup is not used and the mocked HttpClient returns its default response instead of failing. Earlier versions of WithJson ignored additional properties and array elements: to keep that behavior, add .IgnoringAdditionalProperties().IgnoringAdditionalArrayElements() or pass the expected object to WithJsonMatching.