Two tests for Ruby code generator:

- A golden-file test that ensures protoc produces known-valid output.
- A Ruby test that loads that golden file and ensures it actually works
  with the extension.

This split strategy allows us to test end-to-end without needing to
integrate the Ruby gem build system and the protoc build system. This is
desirable because we do not want a gem build/install to depend on
building protoc, and we do not want building protoc to depend on
building and testing the gem.

ruby/google-protobuf.gemspec

@@ -18,5 +18,7 @@ Gem::Specification.new do |s|
   s.files       = ["lib/google/protobuf.rb"] +
                   # extension C source
                   find_c_source("ext/google/protobuf_c")
-  s.test_files = `git ls-files -- tests`.split
+  s.test_files = ["tests/basic.rb",
+		  "tests/stress.rb",
+		  "tests/generated_code_test.rb"]
 end

ruby/tests/generated_code.proto

+syntax = "proto3";
+
+package A.B.C;
+
+message TestMessage {
+  optional int32 optional_int32 = 1;
+  optional int64 optional_int64 = 2;
+  optional uint32 optional_uint32 = 3;
+  optional uint64 optional_uint64 = 4;
+  optional bool optional_bool = 5;
+  optional double optional_double = 6;
+  optional float optional_float = 7;
+  optional string optional_string = 8;
+  optional bytes optional_bytes = 9;
+  optional TestEnum optional_enum = 10;
+  optional TestMessage optional_msg = 11;
+
+  repeated int32 repeated_int32 = 21;
+  repeated int64 repeated_int64 = 22;
+  repeated uint32 repeated_uint32 = 23;
+  repeated uint64 repeated_uint64 = 24;
+  repeated bool repeated_bool = 25;
+  repeated double repeated_double = 26;
+  repeated float repeated_float = 27;
+  repeated string repeated_string = 28;
+  repeated bytes repeated_bytes = 29;
+  repeated TestEnum repeated_enum = 30;
+  repeated TestMessage repeated_msg = 31;
+
+  oneof my_oneof {
+    int32 oneof_int32 = 41;
+    int64 oneof_int64 = 42;
+    uint32 oneof_uint32 = 43;
+    uint64 oneof_uint64 = 44;
+    bool oneof_bool = 45;
+    double oneof_double = 46;
+    float oneof_float = 47;
+    string oneof_string = 48;
+    bytes oneof_bytes = 49;
+    TestEnum oneof_enum = 50;
+    TestMessage oneof_msg = 51;
+  }
+
+  map<int32, string> map_int32_string = 61;
+  map<int64, string> map_int64_string = 62;
+  map<uint32, string> map_uint32_string = 63;
+  map<uint64, string> map_uint64_string = 64;
+  map<bool, string> map_bool_string = 65;
+  map<string, string> map_string_string = 66;
+  map<string, TestMessage> map_string_msg = 67;
+  map<string, TestEnum> map_string_enum = 68;
+  map<string, int32> map_string_int32 = 69;
+  map<string, bool> map_string_bool = 70;
+
+  message NestedMessage {
+    optional int32 foo = 1;
+  }
+
+  optional NestedMessage nested_message = 80;
+}
+
+enum TestEnum {
+  Default = 0;
+  A = 1;
+  B = 2;
+  C = 3;
+}

ruby/tests/generated_code.rb

+# Generated by the protocol buffer compiler.  DO NOT EDIT!
+# source: generated_code.proto
+
+require 'google/protobuf'
+
+Google::Protobuf::DescriptorPool.generated_pool.build do
+  add_message "A.B.C.TestMessage" do
+    optional :optional_int32, :int32, 1
+    optional :optional_int64, :int64, 2
+    optional :optional_uint32, :uint32, 3
+    optional :optional_uint64, :uint64, 4
+    optional :optional_bool, :bool, 5
+    optional :optional_double, :double, 6
+    optional :optional_float, :float, 7
+    optional :optional_string, :string, 8
+    optional :optional_bytes, :string, 9
+    optional :optional_enum, :enum, 10, "A.B.C.TestEnum"
+    optional :optional_msg, :message, 11, "A.B.C.TestMessage"
+    repeated :repeated_int32, :int32, 21
+    repeated :repeated_int64, :int64, 22
+    repeated :repeated_uint32, :uint32, 23
+    repeated :repeated_uint64, :uint64, 24
+    repeated :repeated_bool, :bool, 25
+    repeated :repeated_double, :double, 26
+    repeated :repeated_float, :float, 27
+    repeated :repeated_string, :string, 28
+    repeated :repeated_bytes, :string, 29
+    repeated :repeated_enum, :enum, 30, "A.B.C.TestEnum"
+    repeated :repeated_msg, :message, 31, "A.B.C.TestMessage"
+    repeated :map_int32_string, :message, 61, "A.B.C.TestMessage.MapInt32StringEntry"
+    repeated :map_int64_string, :message, 62, "A.B.C.TestMessage.MapInt64StringEntry"
+    repeated :map_uint32_string, :message, 63, "A.B.C.TestMessage.MapUint32StringEntry"
+    repeated :map_uint64_string, :message, 64, "A.B.C.TestMessage.MapUint64StringEntry"
+    repeated :map_bool_string, :message, 65, "A.B.C.TestMessage.MapBoolStringEntry"
+    repeated :map_string_string, :message, 66, "A.B.C.TestMessage.MapStringStringEntry"
+    repeated :map_string_msg, :message, 67, "A.B.C.TestMessage.MapStringMsgEntry"
+    repeated :map_string_enum, :message, 68, "A.B.C.TestMessage.MapStringEnumEntry"
+    repeated :map_string_int32, :message, 69, "A.B.C.TestMessage.MapStringInt32Entry"
+    repeated :map_string_bool, :message, 70, "A.B.C.TestMessage.MapStringBoolEntry"
+    optional :nested_message, :message, 80, "A.B.C.TestMessage.NestedMessage"
+    oneof :my_oneof do
+      optional :oneof_int32, :int32, 41
+      optional :oneof_int64, :int64, 42
+      optional :oneof_uint32, :uint32, 43
+      optional :oneof_uint64, :uint64, 44
+      optional :oneof_bool, :bool, 45
+      optional :oneof_double, :double, 46
+      optional :oneof_float, :float, 47
+      optional :oneof_string, :string, 48
+      optional :oneof_bytes, :string, 49
+      optional :oneof_enum, :enum, 50, "A.B.C.TestEnum"
+      optional :oneof_msg, :message, 51, "A.B.C.TestMessage"
+    end
+  end
+  add_message "A.B.C.TestMessage.MapInt32StringEntry" do
+    optional :key, :int32, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapInt64StringEntry" do
+    optional :key, :int64, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapUint32StringEntry" do
+    optional :key, :uint32, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapUint64StringEntry" do
+    optional :key, :uint64, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapBoolStringEntry" do
+    optional :key, :bool, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapStringStringEntry" do
+    optional :key, :string, 1
+    optional :value, :string, 2
+  end
+  add_message "A.B.C.TestMessage.MapStringMsgEntry" do
+    optional :key, :string, 1
+    optional :value, :message, 2, "A.B.C.TestMessage"
+  end
+  add_message "A.B.C.TestMessage.MapStringEnumEntry" do
+    optional :key, :string, 1
+    optional :value, :enum, 2, "A.B.C.TestEnum"
+  end
+  add_message "A.B.C.TestMessage.MapStringInt32Entry" do
+    optional :key, :string, 1
+    optional :value, :int32, 2
+  end
+  add_message "A.B.C.TestMessage.MapStringBoolEntry" do
+    optional :key, :string, 1
+    optional :value, :bool, 2
+  end
+  add_message "A.B.C.TestMessage.NestedMessage" do
+    optional :foo, :int32, 1
+  end
+  add_enum "A.B.C.TestEnum" do
+    value :Default, 0
+    value :A, 1
+    value :B, 2
+    value :C, 3
+  end
+end
+
+module A
+  module B
+    module C
+      TestMessage = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage").msgclass
+      TestMessage::MapInt32StringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapInt32StringEntry").msgclass
+      TestMessage::MapInt64StringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapInt64StringEntry").msgclass
+      TestMessage::MapUint32StringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapUint32StringEntry").msgclass
+      TestMessage::MapUint64StringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapUint64StringEntry").msgclass
+      TestMessage::MapBoolStringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapBoolStringEntry").msgclass
+      TestMessage::MapStringStringEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapStringStringEntry").msgclass
+      TestMessage::MapStringMsgEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapStringMsgEntry").msgclass
+      TestMessage::MapStringEnumEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapStringEnumEntry").msgclass
+      TestMessage::MapStringInt32Entry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapStringInt32Entry").msgclass
+      TestMessage::MapStringBoolEntry = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.MapStringBoolEntry").msgclass
+      TestMessage::NestedMessage = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestMessage.NestedMessage").msgclass
+      TestEnum = Google::Protobuf::DescriptorPool.generated_pool.lookup("A.B.C.TestEnum").enummodule
+    end
+  end
+end

ruby/tests/generated_code_test.rb

+#!/usr/bin/ruby
+
+# generated_code.rb is in the same directory as this test.
+$LOAD_PATH.unshift(File.expand_path(File.dirname(__FILE__)))
+
+require 'generated_code'
+require 'test/unit'
+
+class GeneratedCodeTest < Test::Unit::TestCase
+  def test_generated_msg
+    # just test that we can instantiate the message. The purpose of this test
+    # is to ensure that the output of the code generator is valid Ruby and
+    # successfully creates message definitions and classes, not to test every
+    # aspect of the extension (basic.rb is for that).
+    m = A::B::C::TestMessage.new()
+  end
+end

src/Makefile.am

@@ -458,6 +458,7 @@ protobuf_test_SOURCES =                                        \
   google/protobuf/compiler/java/java_plugin_unittest.cc        \
   google/protobuf/compiler/java/java_doc_comment_unittest.cc   \
   google/protobuf/compiler/python/python_plugin_unittest.cc    \
+  google/protobuf/compiler/ruby/ruby_generator_unittest.cc     \
   $(COMMON_TEST_SOURCES)
 nodist_protobuf_test_SOURCES = $(protoc_outputs)
 

src/google/protobuf/compiler/ruby/ruby_generator_unittest.cc

+// Protocol Buffers - Google's data interchange format
+// Copyright 2014 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include <memory>
+
+#include <google/protobuf/compiler/ruby/ruby_generator.h>
+#include <google/protobuf/compiler/command_line_interface.h>
+#include <google/protobuf/io/zero_copy_stream.h>
+#include <google/protobuf/io/printer.h>
+
+#include <google/protobuf/testing/googletest.h>
+#include <gtest/gtest.h>
+#include <google/protobuf/testing/file.h>
+
+namespace google {
+namespace protobuf {
+namespace compiler {
+namespace python {
+namespace {
+
+class TestGenerator : public CodeGenerator {
+ public:
+  TestGenerator() {}
+  ~TestGenerator() {}
+
+  virtual bool Generate(const FileDescriptor* file,
+                        const string& parameter,
+                        GeneratorContext* context,
+                        string* error) const {
+    TryInsert("test_pb2.py", "imports", context);
+    TryInsert("test_pb2.py", "module_scope", context);
+    TryInsert("test_pb2.py", "class_scope:foo.Bar", context);
+    TryInsert("test_pb2.py", "class_scope:foo.Bar.Baz", context);
+    return true;
+  }
+
+  void TryInsert(const string& filename, const string& insertion_point,
+                 GeneratorContext* context) const {
+    google::protobuf::scoped_ptr<io::ZeroCopyOutputStream> output(
+        context->OpenForInsert(filename, insertion_point));
+    io::Printer printer(output.get(), '$');
+    printer.Print("// inserted $name$\n", "name", insertion_point);
+  }
+};
+
+// This test is a simple golden-file test over the output of the Ruby code
+// generator. When we make changes to the Ruby extension and alter the Ruby code
+// generator to use those changes, we should (i) manually test the output of the
+// code generator with the extension, and (ii) update the golden output above.
+// Some day, we may integrate build systems between protoc and the language
+// extensions to the point where we can do this test in a more automated way.
+
+TEST(RubyGeneratorTest, GeneratorTest) {
+  google::protobuf::compiler::CommandLineInterface cli;
+  cli.SetInputsAreProtoPathRelative(true);
+
+  ruby::Generator ruby_generator;
+  cli.RegisterGenerator("--ruby_out", &ruby_generator, "");
+
+  string path_arg = "-I" + TestSourceDir() + "/ruby/tests";
+  string ruby_out = "--ruby_out=" + TestTempDir();
+  const char* argv[] = {
+    "protoc",
+    path_arg.c_str(),
+    ruby_out.c_str(),
+    "generated_code.proto",
+  };
+
+  EXPECT_EQ(0, cli.Run(4, argv));
+
+  string output;
+  GOOGLE_CHECK_OK(File::GetContents(TestTempDir() + "/generated_code.rb",
+                                    &output,
+                                    true));
+
+  string expected_output;
+  GOOGLE_CHECK_OK(File::GetContents(
+      TestSourceDir() + "/ruby/tests/generated_code.rb",
+      &expected_output,
+      true));
+
+  EXPECT_EQ(expected_output, output);
+}
+
+}  // namespace
+}  // namespace python
+}  // namespace compiler
+}  // namespace protobuf
+}  // namespace google