HttpEncodingAutoConfiguration is not added to the WebMvcTest slice

[rob-valor]

Affects: 5.4.3

HttpEncodingAutoConfiguration is not added to the WebMvcTest slice. Not sure if this is intentional but when running with full auto-configuration this configuration is loaded in the application context. When starting a test application context with @WebMvcTest the CharacterEncodingFilter provided by the HttpEncodingAutoConfiguration is not added which makes http request processing different in those tests compared to @SpringBootTest or production application context. By default that filter makes request character encoding always UTF-8. see (filter config with default utf-8 being forced for requests)

This is triggered by spring-projects/spring-framework#22788. That made us use MediaType.APPLICATION_JSON (without the character encoding) for the requests during WebMvcTests.

[bclozel]

Indeed, the WebMvcTypeExcludeFilter includes FilterRegistrationBean but not the HttpEncodingAutoConfiguration, which configures the CharacterEncodingFilter if the configuration property is set.