lsd-interceptors

A library containing various automated message/event interceptors that can be used along with the lsd-core library
to generate reports containing sequence diagrams of the captured events. e.g.

Autoconfig

This library is designed with @SpringBootTest in mind and attempts to minimise boilerplate code by wiring up default
bean configurations based on the beans and classes available in the project.

The interceptors can be used outside of a spring project but will require some manual setup. The classes in the
com/nickmcdowall/lsd/interceptor/autoconfigure package would be a good starting point for examples on how to configure
the interceptors when autowiring is not an option.

To disable autoconfig so that the beans can be used in another library add the following property:

lsd.interceptors.autoconfig.enabled=false

Available Interceptors

LsdRestTemplateInterceptor

If a TestState bean exists and a RestTemplate class is on the classpath then a RestTemplateCustomizer bean will be
loaded into the default RestTemplateBuilder bean.

This causes an interceptor to be injected along with a BufferingClientHttpRequestFactory to allow for multiple reads
of the response stream (to avoid breaking the chain on additional reads).

• Don’t instantiate a RestTemplate bean using the default constructor (or else you won’t get the interceptor and
  factory out the box), avoid:

    // Wrong
@Bean
public RestTemplate restTemplate(){
        return new RestTemplate();
        }

instead use a RestTemplateBuilder bean which will provide a correctly configured bean:

    // Correct
@Bean
public RestTemplate restTemplate(RestTemplateBuilder builder){
        return builder.build();
        }

• TestRestTemplate beans just need to be @Autowired into your tests and will be instantiated and configured for you.

LsdFeignLoggerInterceptor

• For Feign clients
• Auto configured if a TestState bean exists and both FeignClientBuilder and Logger.Level classes are on the
  classpath. Note that if no feign Logger.Level bean exists one will be created (Logger.Level.BASIC) to enable the
  interceptor to work. If one exists it will not be replaced.

LsdOkHttpInterceptor

• For OkHttpClient clients.
• Auto configured if TestState and OkHttpClient.Builder beans exists and has spring
  property lsd.interceptors.autoconfig.okhttp.enabled=true
  (requires explicit property to prevent clashing with LsdFeignLoggerInterceptor - as it is a popular client
  implementation for Feign and the former interceptor should work across all Feign client implementations).

Spring AOP

Another option is to use Spring AOP
for intercepting calls - e.g. if you want to capture method calls to any method in YourClass that takes one argument you
may have something like this in your acceptance/component tests (requires spring aop dependencies):

@Aspect
@Component
@EnableAspectJAutoProxy
public class YourClassLsdInterceptor {
    @Before("execution(* com.your.package.YourClass.*(*) && args(yourArg))")
    public void captureEvents(JoinPoint joinpoint, Object yourArg) {
        var methodName = joinpoint.getSignature().getName();
        var yourArgType = yourArg.getClass().getSimpleName();
        testState.log(methodName + "( " + yourArgType + " ) from A to B", yourArg);
    }
}

(Additional interceptors and auto-configuration will be added over time).

Naming

Source Name

If you set the property info.app.name then this will be used as the default source name for interactions captured on
the sequence diagrams. (i.e. your app is calling downstream services)

This can be overridden by setting the Source-Name http header on a request. For example if you want to create a client
that represents a user calling into your app say from within a test then you can set the Source-Name header value to
the name of the user.

If neither are set then the library will default to the value App.

Destination Name

Set the Target-Name header value to control the name of the destination service of an interaction on the sequence
diagrams.

If this header is not set the library will attempt to derive a destination name based on the path of the http request.

Properties

The following properties can be overridden by adding a properties file called lsd.properties on the classpath of your
application.

Build

Requirements

• Java 11

Git hooks

The custom hooks in .githooks will be configured when gradle clean is run.

Build

./gradlew clean build

Release

Releases are automated via the semantic-release github action when commits are merged into the remote master