Merge pull request #13 from jwfang/json-print-opt

ResponseToJsonTranslator supports JsonPrintOptions

Author: lizan

src/include/grpc_transcoding/response_to_json_translator.h

@@ -19,6 +19,7 @@
 
 #include "google/protobuf/io/zero_copy_stream.h"
 #include "google/protobuf/stubs/status.h"
+#include "google/protobuf/util/json_util.h"
 #include "google/protobuf/util/type_resolver.h"
 #include "message_reader.h"
 #include "message_stream.h"
@@ -64,9 +65,15 @@ class ResponseToJsonTranslator : public MessageStream {
   // streaming - whether this is a streaming call or not
   // in - the input stream of delimited proto message(s) as in the gRPC wire
   //      format (http://www.grpc.io/docs/guides/wire.html)
+  // json_print_options - control various aspects for the generated JSON, such
+  //      as indentation, weather to omit fields with default values, etc (
+  //      https://developers.google.com/protocol-buffers/docs/reference/cpp/
+  //      google.protobuf.util.json_util#JsonPrintOptions
   ResponseToJsonTranslator(
       ::google::protobuf::util::TypeResolver* type_resolver,
-      std::string type_url, bool streaming, TranscoderInputStream* in);
+      std::string type_url, bool streaming, TranscoderInputStream* in,
+      const ::google::protobuf::util::JsonPrintOptions&
+          json_print_options = ::google::protobuf::util::JsonPrintOptions());
 
   // MessageStream implementation
   bool NextMessage(std::string* message);
@@ -80,6 +87,7 @@ class ResponseToJsonTranslator : public MessageStream {
 
   ::google::protobuf::util::TypeResolver* type_resolver_;
   std::string type_url_;
+  const ::google::protobuf::util::JsonPrintOptions json_print_options_;
   bool streaming_;
 
   // A MessageReader to extract full messages

src/response_to_json_translator.cc

@@ -20,7 +20,6 @@
 
 #include "google/protobuf/io/zero_copy_stream_impl_lite.h"
 #include "google/protobuf/stubs/status.h"
-#include "google/protobuf/util/json_util.h"
 #include "google/protobuf/util/type_resolver.h"
 
 namespace google {
@@ -30,9 +29,11 @@ namespace transcoding {
 
 ResponseToJsonTranslator::ResponseToJsonTranslator(
     ::google::protobuf::util::TypeResolver* type_resolver, std::string type_url,
-    bool streaming, TranscoderInputStream* in)
+    bool streaming, TranscoderInputStream* in,
+    const ::google::protobuf::util::JsonPrintOptions& json_print_options)
     : type_resolver_(type_resolver),
       type_url_(std::move(type_url)),
+      json_print_options_(json_print_options),
       streaming_(streaming),
       reader_(in),
       first_(true),
@@ -118,7 +119,7 @@ bool ResponseToJsonTranslator::TranslateMessage(
 
   // Do the actual translation.
   status_ = ::google::protobuf::util::BinaryToJsonStream(
-      type_resolver_, type_url_, proto_in, &json_stream);
+      type_resolver_, type_url_, proto_in, &json_stream, json_print_options_);
   if (!status_.ok()) {
     return false;
   }

test/response_to_json_translator_test.cc

@@ -57,15 +57,17 @@ class ResponseToJsonTranslatorTestRun {
   // input - the input to be passed to the MessageReader,
   // expected - the expected translated json chunks as the input is processed,
   ResponseToJsonTranslatorTestRun(pbutil::TypeResolver* type_resolver,
-                                  bool streaming, const std::string& type_url,
-                                  const std::string& input,
-                                  const std::vector<ExpectedAt>& expected)
+                            bool streaming, const std::string& type_url,
+                            const pbutil::JsonPrintOptions& json_print_options,
+                            const std::string& input,
+                            const std::vector<ExpectedAt>& expected)
       : input_(input),
         expected_(expected),
         streaming_(streaming),
         input_stream_(new TestZeroCopyInputStream()),
         translator_(new ResponseToJsonTranslator(
-            type_resolver, type_url, streaming_, input_stream_.get())),
+            type_resolver, type_url, streaming_, input_stream_.get(),
+            json_print_options)),
         position_(0),
         next_expected_(std::begin(expected_)) {}
 
@@ -186,19 +188,21 @@ class ResponseToJsonTranslatorTestCase {
   // input - the input to be passed to the MessageReader,
   // expected - the expected translated json chunks as the input is processed,
   ResponseToJsonTranslatorTestCase(pbutil::TypeResolver* type_resolver,
-                                   bool streaming, const std::string& type_url,
-                                   std::string input,
-                                   std::vector<ExpectedAt> expected)
+                           bool streaming, const std::string& type_url,
+                           const pbutil::JsonPrintOptions& json_print_options,
+                           std::string input, std::vector<ExpectedAt> expected)
       : type_resolver_(type_resolver),
         streaming_(streaming),
         type_url_(type_url),
+        json_print_options_(json_print_options),
         input_(std::move(input)),
         expected_(std::move(expected)) {}
 
   std::unique_ptr<ResponseToJsonTranslatorTestRun> NewRun() {
     return std::unique_ptr<ResponseToJsonTranslatorTestRun>(
         new ResponseToJsonTranslatorTestRun(type_resolver_, streaming_,
-                                            type_url_, input_, expected_));
+                                            type_url_, json_print_options_,
+                                            input_, expected_));
   }
 
   // Runs the test for different partitions of the input.
@@ -234,6 +238,7 @@ class ResponseToJsonTranslatorTestCase {
   pbutil::TypeResolver* type_resolver_;
   bool streaming_;
   std::string type_url_;
+  pbutil::JsonPrintOptions json_print_options_;
 
   // The entire input including message delimiters
   std::string input_;
@@ -261,6 +266,21 @@ class ResponseToJsonTranslatorTest : public ::testing::Test {
     type_url_ = "type.googleapis.com/" + type_name;
   }
 
+  // Sets json print options type for used in this test. Must be used before
+  // Build().
+  void SetJsonPrintOptions(const pbutil::JsonPrintOptions& json_print_options) {
+    json_print_options_ = json_print_options;
+  }
+
+  // Sets whether always print primitive fields for default values. Must be used
+  // before Build(). The default is false.
+  void SetJsonAlwaysPrintPrimitiveFields(bool always_print_primitive_fields) {
+    pbutil::JsonPrintOptions json_print_options;
+    json_print_options.always_print_primitive_fields =
+                                                always_print_primitive_fields;
+    SetJsonPrintOptions(json_print_options);
+  }
+
   // Sets whether this is a streaming call or not. Must be used before Build().
   // The default is non-streaming.
   void SetStreaming(bool streaming) { streaming_ = streaming; }
@@ -285,15 +305,16 @@ class ResponseToJsonTranslatorTest : public ::testing::Test {
 
     return std::unique_ptr<ResponseToJsonTranslatorTestCase>(
         new ResponseToJsonTranslatorTestCase(
-            type_helper_->Resolver(), streaming_, type_url_, std::move(input),
-            std::move(expected)));
+            type_helper_->Resolver(), streaming_, type_url_, json_print_options_,
+            std::move(input), std::move(expected)));
   }
 
  private:
   ::google::api::Service service_;
   std::unique_ptr<TypeHelper> type_helper_;
 
   std::string type_url_;
+  pbutil::JsonPrintOptions json_print_options_;
   bool streaming_;
 
   // The entire input
@@ -316,6 +337,20 @@ TEST_F(ResponseToJsonTranslatorTest, Simple) {
   EXPECT_TRUE(tc->Test(4, 0.5));
 }
 
+TEST_F(ResponseToJsonTranslatorTest, SimpleAlwaysPrintPrimitiveFields) {
+  ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
+  SetMessageType("Shelf");
+  SetJsonAlwaysPrintPrimitiveFields(true);
+  AddMessage<Shelf>(R"(name : "" theme : "")",
+                    R"({ "name" : "", "theme" : ""})");
+
+  auto tc = Build();
+  EXPECT_TRUE(tc->Test(1, 1.0));
+  EXPECT_TRUE(tc->Test(2, 1.0));
+  EXPECT_TRUE(tc->Test(3, 1.0));
+  EXPECT_TRUE(tc->Test(4, 0.5));
+}
+
 TEST_F(ResponseToJsonTranslatorTest, Nested) {
   ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
   SetMessageType("Book");
@@ -355,6 +390,46 @@ TEST_F(ResponseToJsonTranslatorTest, Nested) {
   EXPECT_TRUE(tc->Test(3, 0.2));
 }
 
+TEST_F(ResponseToJsonTranslatorTest, NestedAlwaysPrintPrimitiveFields) {
+  ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
+  SetMessageType("Book");
+  SetJsonAlwaysPrintPrimitiveFields(true);
+  AddMessage<Book>(
+      R"(
+          name : ""
+          author : ""
+          title : ""
+          author_info {
+            first_name : ""
+            last_name : ""
+            bio {
+              year_born : 0
+              year_died : 0
+              text : ""
+            }
+          }
+        )",
+      R"({
+          "author" : "",
+          "name" : "",
+          "title" : "",
+          "authorInfo" : {
+            "firstName" : "",
+            "lastName" : "",
+            "bio" : {
+              "yearBorn" : "0",
+              "yearDied" : "0",
+              "text" : ""
+            }
+          }
+        })");
+
+  auto tc = Build();
+  EXPECT_TRUE(tc->Test(1, 1.0));
+  EXPECT_TRUE(tc->Test(2, 1.0));
+  EXPECT_TRUE(tc->Test(3, 0.2));
+}
+
 TEST_F(ResponseToJsonTranslatorTest, Empty) {
   ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
   SetMessageType("Shelf");
@@ -365,6 +440,18 @@ TEST_F(ResponseToJsonTranslatorTest, Empty) {
   EXPECT_TRUE(tc->Test(2, 1.0));
 }
 
+TEST_F(ResponseToJsonTranslatorTest, EmptyAlwaysPrintPrimitiveFields) {
+  ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
+  SetMessageType("Shelf");
+  SetJsonAlwaysPrintPrimitiveFields(true);
+  AddMessage<Shelf>(R"()",
+                    R"({ "name" : "", "theme" : ""})");
+
+  auto tc = Build();
+  EXPECT_TRUE(tc->Test(1, 1.0));
+  EXPECT_TRUE(tc->Test(2, 1.0));
+}
+
 TEST_F(ResponseToJsonTranslatorTest, DifferentSizes) {
   ASSERT_TRUE(LoadService("bookstore_service.pb.txt"));
   SetMessageType("Shelf");