Serialize subscription errors as json

service/src/main/java/org/whispersystems/textsecuregcm/mappers/SubscriptionExceptionMapper.java

@@ -5,11 +5,9 @@
 
 package org.whispersystems.textsecuregcm.mappers;
 
-import javax.ws.rs.BadRequestException;
-import javax.ws.rs.ClientErrorException;
-import javax.ws.rs.ForbiddenException;
-import javax.ws.rs.InternalServerErrorException;
-import javax.ws.rs.NotFoundException;
+import io.dropwizard.jersey.errors.ErrorMessage;
+import javax.ws.rs.WebApplicationException;
+import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
 import javax.ws.rs.ext.ExceptionMapper;
 import org.whispersystems.textsecuregcm.storage.SubscriptionException;
@@ -18,14 +16,24 @@ public class SubscriptionExceptionMapper implements ExceptionMapper<Subscription
 
   @Override
   public Response toResponse(final SubscriptionException exception) {
-    return switch (exception) {
-      case SubscriptionException.NotFound e -> new NotFoundException(e.getMessage(), e.getCause()).getResponse();
-      case SubscriptionException.Forbidden e -> new ForbiddenException(e.getMessage(), e.getCause()).getResponse();
-      case SubscriptionException.InvalidArguments e ->
-          new BadRequestException(e.getMessage(), e.getCause()).getResponse();
-      case SubscriptionException.ProcessorConflict e ->
-          new ClientErrorException("existing processor does not match", Response.Status.CONFLICT).getResponse();
-      default -> new InternalServerErrorException(exception.getMessage(), exception.getCause()).getResponse();
-    };
+    final Response.Status status = (switch (exception) {
+      case SubscriptionException.NotFound e -> Response.Status.NOT_FOUND;
+      case SubscriptionException.Forbidden e -> Response.Status.FORBIDDEN;
+      case SubscriptionException.InvalidArguments e -> Response.Status.BAD_REQUEST;
+      case SubscriptionException.ProcessorConflict e -> Response.Status.CONFLICT;
+      default -> Response.Status.INTERNAL_SERVER_ERROR;
+    });
+
+    // If the SubscriptionException came with suitable error message, include that in the response body. Otherwise,
+    // don't provide any message to the WebApplicationException constructor so the response includes the default
+    // HTTP error message for the status.
+    final WebApplicationException wae = exception.errorDetail()
+        .map(errorMessage -> new WebApplicationException(errorMessage, exception, Response.status(status).build()))
+        .orElseGet(() -> new WebApplicationException(exception, Response.status(status).build()));
+
+    return Response
+        .fromResponse(wae.getResponse())
+        .type(MediaType.APPLICATION_JSON_TYPE)
+        .entity(new ErrorMessage(wae.getResponse().getStatus(), wae.getLocalizedMessage())).build();
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/storage/SubscriptionException.java

@@ -4,30 +4,51 @@
  */
 package org.whispersystems.textsecuregcm.storage;
 
+import java.util.Optional;
+import javax.annotation.Nullable;
+
 public class SubscriptionException extends Exception {
-  public SubscriptionException(String message, Exception cause) {
-    super(message, cause);
+
+  private @Nullable String errorDetail;
+
+  public SubscriptionException(Exception cause) {
+    this(cause, null);
+  }
+
+  SubscriptionException(Exception cause, String errorDetail) {
+    super(cause);
+    this.errorDetail = errorDetail;
+  }
+
+  /**
+   * @return An error message suitable to include in a client response
+   */
+  public Optional<String> errorDetail() {
+    return Optional.ofNullable(errorDetail);
   }
 
   public static class NotFound extends SubscriptionException {
+
     public NotFound() {
-      super(null, null);
+      super(null);
     }
 
     public NotFound(Exception cause) {
-      super(null, cause);
+      super(cause);
     }
   }
 
   public static class Forbidden extends SubscriptionException {
+
     public Forbidden(final String message) {
-      super(message, null);
+      super(null, message);
     }
   }
 
   public static class InvalidArguments extends SubscriptionException {
+
     public InvalidArguments(final String message, final Exception cause) {
-      super(message, cause);
+      super(cause, message);
     }
   }
 
@@ -45,7 +66,7 @@ public class SubscriptionException extends Exception {
 
   public static class ProcessorConflict extends SubscriptionException {
     public ProcessorConflict(final String message) {
-      super(message, null);
+      super(null, message);
     }
   }
 }

service/src/main/java/org/whispersystems/textsecuregcm/storage/SubscriptionManager.java

@@ -263,7 +263,7 @@ public class SubscriptionManager {
           final String customerId = updatedRecord.getProcessorCustomer()
               .filter(pc -> pc.processor().equals(subscriptionPaymentProcessor.getProvider()))
               .orElseThrow(() ->
-                  ExceptionUtils.wrap(new SubscriptionException("record should not be missing customer", null)))
+                  ExceptionUtils.wrap(new SubscriptionException(null, "record should not be missing customer")))
               .customerId();
           return paymentSetupFunction.apply(subscriptionPaymentProcessor, customerId);
         });