fix: issue with error serialization

NOTE: encountered a weird case where error is not considered an instance
of Error during JSON.stringify with custom replacer.

const err = new HttpStatusError(202, 'ok')

JSON.stringify({ error: err }, customReplacers) was producing
the following results

replacer(key, value) {
  // when key === '' - top level
  value.error instanceof Error === true

  // when key === 'error'
  value instanceof Errorr === false
}

This works around it as our common shape for reply is { error, data }

src/utils/serialization.js

@@ -58,10 +58,14 @@ function deserializeError(error) {
 }
 
 function jsonSerializer(key, value) {
-  if (is.instance(value, Error)) {
+  if (value instanceof Error) {
     return serializeError(value);
   }
 
+  if (value && value.error instanceof Error) {
+    value.error = serializeError(value.error);
+  }
+
   return value;
 }
 

test/amqp-transport.js

@@ -166,12 +166,16 @@ describe('AMQPTransport', function AMQPTransportTestSuite() {
       cache: 100,
       exchange: configuration.exchange,
       queue: 'test-queue',
-      listen: 'test.default',
+      listen: ['test.default', 'test.throw'],
       connection: configuration.connection,
     };
 
-    const amqp = await AMQPTransport.connect(opts, (message, headers, actions, callback) => {
-      callback(null, {
+    const amqp = await AMQPTransport.connect(opts, (message, properties, actions, callback) => {
+      if (properties.routingKey === 'test.throw') {
+        return callback(new HttpStatusError(202, 'ok'));
+      }
+
+      return callback(null, {
         resp: typeof message === 'object' ? message : `${message}-response`,
         time: process.hrtime(),
       });
@@ -187,6 +191,15 @@ describe('AMQPTransport', function AMQPTransportTestSuite() {
     ))
   ));
 
+  it('error is correctly deserialized', async () => {
+    await assert.rejects(this.amqp.publishAndWait('test.throw', {}), {
+      name: 'HttpStatusError',
+      message: 'ok',
+      statusCode: 202,
+      status_code: 202,
+    });
+  });
+
   it('is able to publish to route consumer', async () => {
     const response = await this.amqp
       .publishAndWait('test.default', 'test-message');