Introduce abstraction layer for RESTeasy mock dispatcher

scm-test/src/main/java/sonia/scm/web/ScmTestDispatcher.java

@@ -0,0 +1,109 @@
+package sonia.scm.web;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import org.apache.shiro.authz.AuthorizationException;
+import org.apache.shiro.authz.UnauthorizedException;
+import org.jboss.resteasy.mock.MockDispatcherFactory;
+import org.jboss.resteasy.spi.Dispatcher;
+import org.jboss.resteasy.spi.HttpRequest;
+import org.jboss.resteasy.spi.HttpResponse;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import sonia.scm.AlreadyExistsException;
+import sonia.scm.BadRequestException;
+import sonia.scm.ConcurrentModificationException;
+import sonia.scm.NotFoundException;
+
+import javax.ws.rs.Produces;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.Status;
+import javax.ws.rs.ext.ContextResolver;
+import javax.ws.rs.ext.ExceptionMapper;
+import javax.ws.rs.ext.Provider;
+import java.util.HashMap;
+import java.util.Map;
+
+public class ScmTestDispatcher {
+
+  private static final Logger LOG = LoggerFactory.getLogger(ScmTestDispatcher.class);
+
+  private final Dispatcher dispatcher;
+  private final EnhanceableExceptionMapper exceptionMapper;
+
+  public ScmTestDispatcher() {
+    dispatcher = MockDispatcherFactory.createDispatcher();
+    exceptionMapper = new EnhanceableExceptionMapper();
+    dispatcher.getProviderFactory().register(exceptionMapper);
+    dispatcher.getProviderFactory().registerProviderInstance(new JacksonProducer());
+  }
+
+  public void addSingletonResource(Object resource) {
+    dispatcher.getRegistry().addSingletonResource(resource);
+  }
+
+  public void invoke(HttpRequest in, HttpResponse response) {
+    dispatcher.invoke(in, response);
+  }
+
+  public void registerException(Class<? extends RuntimeException> exceptionClass, Status status) {
+    exceptionMapper.registerException(exceptionClass, status);
+  }
+
+  public <T> void putDefaultContextObject(Class<T> clazz, T object) {
+    dispatcher.getDefaultContextObjects().put(clazz, object);
+  }
+
+  private static class EnhanceableExceptionMapper implements ExceptionMapper<Exception> {
+
+    private final Map<Class<? extends RuntimeException>, Integer> statusCodes = new HashMap<>();
+
+    public EnhanceableExceptionMapper() {
+      registerException(NotFoundException.class, Status.NOT_FOUND);
+      registerException(AlreadyExistsException.class, Status.CONFLICT);
+      registerException(ConcurrentModificationException.class, Status.CONFLICT);
+      registerException(UnauthorizedException.class, Status.FORBIDDEN);
+      registerException(AuthorizationException.class, Status.FORBIDDEN);
+      registerException(BadRequestException.class, Status.BAD_REQUEST);
+    }
+
+    private void registerException(Class<? extends RuntimeException> exceptionClass, Status status) {
+      statusCodes.put(exceptionClass, status.getStatusCode());
+    }
+
+    @Override
+    public Response toResponse(Exception e) {
+      return Response.status(getStatus(e)).entity(e.getMessage()).build();
+    }
+
+    private Integer getStatus(Exception ex) {
+      return statusCodes
+        .entrySet()
+        .stream()
+        .filter(e -> e.getKey().isAssignableFrom(ex.getClass()))
+        .map(Map.Entry::getValue)
+        .findAny()
+        .orElse(handleUnknownException(ex));
+    }
+
+    private Integer handleUnknownException(Exception ex) {
+      LOG.info("got unknown exception in rest api test", ex);
+      return 500;
+    }
+  }
+
+  @Provider
+  @Produces("application/*+json")
+  public static class JacksonProducer implements ContextResolver<ObjectMapper> {
+    public JacksonProducer() {
+      this.json
+        = new ObjectMapper().findAndRegisterModules();
+    }
+
+    @Override
+    public ObjectMapper getContext(Class<?> objectType) {
+      return json;
+    }
+
+    private final ObjectMapper json;
+  }
+}