closes #26

Author: Adven27

README.md

@@ -1,6 +1,6 @@
 [![Stability: Maintenance](https://masterminds.github.io/stability/maintenance.svg)](https://masterminds.github.io/stability/maintenance.html)
 [![Docker Cloud Build Status](https://img.shields.io/docker/cloud/build/adven27/grpc-wiremock?label=build&logo=docker)](https://hub.docker.com/repository/docker/adven27/grpc-wiremock/builds)
-[![Docker Image Version (tag latest semver)](https://img.shields.io/docker/v/adven27/grpc-wiremock/1.3.1?logo=docker)](https://hub.docker.com/repository/docker/adven27/grpc-wiremock/general)
+[![Docker Image Version (tag latest semver)](https://img.shields.io/docker/v/adven27/grpc-wiremock/1.3.2?logo=docker)](https://hub.docker.com/repository/docker/adven27/grpc-wiremock/general)
 
 # Overview
 grpc-wiremock is a **mock server** for **GRPC** services implemented as a wrapper around the [WireMock](http://wiremock.org) http server.
@@ -26,7 +26,7 @@ curl -X POST http://localhost:8888/__admin/mappings \
         "url": "/BalanceService/getUserBalance",
         "headers": {"withAmount": {"matches": "\\d+\\.?\\d*"} },
         "bodyPatterns" : [ {
-            "equalToJson" : { "id": "1", "currency": "EUR" }
+            "equalToJson" : { "userId": "1", "currency": "EUR" }
         } ]
     },
     "response": {
@@ -212,7 +212,6 @@ Also in docker-compose:
 ```
 <sub>*gzip compression supported by default</sub>
 
-
 ### 6. Use in load testing
 
 To increase performance some Wiremock related options may be tuned either directly or by enabling the "load" profile. 
@@ -228,3 +227,23 @@ docker run \
   -e WIREMOCK_ASYNC-RESPONSE-THREADS=10 \
   adven27/grpc-wiremock
 ```
+
+### 7. Preserving proto field names in stubs
+
+By default, stub mappings must have proto fields references in lowerCamlCase, e.g. proto field `user_id` must be referenced as:
+
+```json
+{
+  "request": {
+    "method": "POST",
+    "url": "/BalanceService/getUserBalance",
+    "bodyPatterns": [{"equalToJson": { "userId": "1" }}]
+  }
+}
+```
+
+To preserve proto field names the following env variable could be used:
+
+```posh
+docker run -e JSON_PRESERVING_PROTO_FIELD_NAMES=true adven27/grpc-wiremock
+```

build.gradle

@@ -1,5 +1,5 @@
 plugins {
-    id 'org.springframework.boot' version '2.5.5'
+    id 'org.springframework.boot' version '2.5.6'
     id 'io.spring.dependency-management' version '1.0.11.RELEASE'
     id 'java'
     id 'com.google.protobuf' version '0.8.16'

example/proto/wallet.proto

@@ -15,7 +15,7 @@ service BalanceService {
 }
 
 message UserBalanceRequest {
-  uint64 id = 1;
+  uint64 user_id = 1;
   string currency = 2;
 }
 
@@ -47,7 +47,7 @@ message TransactionResponse {
   uint64 userId = 2;
   string currency = 3;
   common.proto.ProtoBigDecimal amount = 4;
-  common.proto.ProtoTimestamp transactionDate = 5;
+  common.proto.ProtoTimestamp transaction_date = 5;
 }
 
 message SearchTransactionRequest {

src/main/java/io/adven/grpc/wiremock/HttpMock.java

@@ -2,11 +2,8 @@
 
 import com.github.tomakehurst.wiremock.WireMockServer;
 import com.github.tomakehurst.wiremock.standalone.CommandLineOptions;
-import com.google.protobuf.AbstractMessage;
-import com.google.protobuf.InvalidProtocolBufferException;
 import com.google.protobuf.Message;
 import com.google.protobuf.MessageOrBuilder;
-import com.google.protobuf.util.JsonFormat;
 import io.adven.grpc.wiremock.configurer.WiremockConfigurer;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -16,7 +13,6 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.UncheckedIOException;
-import java.lang.reflect.InvocationTargetException;
 import java.net.URI;
 import java.net.http.HttpClient;
 import java.net.http.HttpRequest;
@@ -33,11 +29,13 @@ public class HttpMock {
     private static final Logger LOG = LoggerFactory.getLogger(HttpMock.class);
     private static final String PREFIX = "wiremock_";
     private final WiremockConfigurer configurer;
+    private final ProtoJsonConverter converter;
     private WireMockServer server;
     private final HttpClient httpClient = HttpClient.newHttpClient();
 
-    public HttpMock(WiremockConfigurer configurer) {
+    public HttpMock(WiremockConfigurer configurer, ProtoJsonConverter converter) {
         this.configurer = configurer;
+        this.converter = converter;
     }
 
     public void start() {
@@ -90,7 +88,8 @@ public Response request(String path, Object message, Map<String, String> headers
                     .headers(headers.entrySet().stream().flatMap(e -> Stream.of(e.getKey(), e.getValue())).toArray(String[]::new))
                     .build(),
                 HttpResponse.BodyHandlers.ofInputStream()
-            )
+            ),
+            converter
         );
     }
 
@@ -100,14 +99,16 @@ public Response request(String path, Object message) throws IOException, Interru
 
     public static final class Response {
         private final HttpResponse<InputStream> httpResponse;
+        private final ProtoJsonConverter converter;
 
-        public Response(HttpResponse<InputStream> httpResponse) {
+        public Response(HttpResponse<InputStream> httpResponse, ProtoJsonConverter converter) {
             this.httpResponse = httpResponse;
+            this.converter = converter;
         }
 
         public Message getMessage(Class<?> aClass) {
             if (httpResponse.statusCode() == 200) {
-                return ProtoJsonUtil.fromJson(getBody(), aClass);
+                return converter.fromJson(getBody(), aClass);
             }
             throw new BadHttpResponseException(httpResponse.statusCode(), getBody());
         }
@@ -130,26 +131,6 @@ private boolean isGzip() {
     }
 
     private HttpRequest.BodyPublisher asJson(Object arg) throws IOException {
-        return HttpRequest.BodyPublishers.ofString(ProtoJsonUtil.toJson((MessageOrBuilder) arg));
-    }
-
-    private static final class ProtoJsonUtil {
-        static String toJson(MessageOrBuilder messageOrBuilder) throws IOException {
-            return JsonFormat.printer().print(messageOrBuilder);
-        }
-
-        @SuppressWarnings({"unchecked", "rawtypes"})
-        static <T extends Message> T fromJson(String json, Class<?> clazz) {
-            try {
-                LOG.info("Converting to {} json:\n{}", clazz, json);
-                AbstractMessage.Builder builder = (AbstractMessage.Builder) clazz.getMethod("newBuilder").invoke(null);
-                JsonFormat.parser().merge(json, builder);
-                T result = (T) builder.build();
-                LOG.info("Grpc response:\n{}", result);
-                return result;
-            } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException | InvalidProtocolBufferException e) {
-                throw new IllegalArgumentException("Failed to convert " + json + " to " + clazz, e);
-            }
-        }
+        return HttpRequest.BodyPublishers.ofString(converter.toJson((MessageOrBuilder) arg));
     }
 }

src/main/java/io/adven/grpc/wiremock/ProtoJsonConverter.java

@@ -0,0 +1,42 @@
+package io.adven.grpc.wiremock;
+
+import com.google.protobuf.AbstractMessage;
+import com.google.protobuf.InvalidProtocolBufferException;
+import com.google.protobuf.Message;
+import com.google.protobuf.MessageOrBuilder;
+import com.google.protobuf.util.JsonFormat;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+import java.io.IOException;
+import java.lang.reflect.InvocationTargetException;
+
+@Component
+public class ProtoJsonConverter {
+    private static final Logger LOG = LoggerFactory.getLogger(HttpMock.class);
+    private final JsonFormat.Printer printer;
+
+    public ProtoJsonConverter(@Value("${json.preserving.proto.field.names:false}") boolean preservingProtoFieldNames) {
+        printer = preservingProtoFieldNames ? JsonFormat.printer().preservingProtoFieldNames() : JsonFormat.printer();
+    }
+
+    public String toJson(MessageOrBuilder messageOrBuilder) throws IOException {
+        return printer.print(messageOrBuilder);
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    public <T extends Message> T fromJson(String json, Class<?> clazz) {
+        try {
+            LOG.info("Converting to {} json:\n{}", clazz, json);
+            AbstractMessage.Builder builder = (AbstractMessage.Builder) clazz.getMethod("newBuilder").invoke(null);
+            JsonFormat.parser().merge(json, builder);
+            T result = (T) builder.build();
+            LOG.info("Grpc response:\n{}", result);
+            return result;
+        } catch (IllegalAccessException | InvocationTargetException | NoSuchMethodException | InvalidProtocolBufferException e) {
+            throw new IllegalArgumentException("Failed to convert " + json + " to " + clazz, e);
+        }
+    }
+}

src/main/resources/application.yaml

@@ -26,4 +26,4 @@ grpc:
 ---
 spring.config.activate.on-profile: load
 #
-logging.level.io.adven.grpc.wiremock.HttpMock: warn
+logging.level.io.adven.grpc: warn