From 76c6d91ff52969ef00b310c97f11ec7768685f0e Mon Sep 17 00:00:00 2001
From: dbolduc <dbolduc@google.com>
Date: Sun, 7 Aug 2022 19:04:32 -0400
Subject: [PATCH] feat(spanner): equality for copyable classes

---
 .../cloud/spanner/create_instance_request_builder.h   | 11 +++++++++++
 .../spanner/create_instance_request_builder_test.cc   | 10 ++++++++++
 .../cloud/spanner/update_instance_request_builder.h   | 11 +++++++++++
 .../spanner/update_instance_request_builder_test.cc   |  9 +++++++++
 4 files changed, 41 insertions(+)

diff --git a/google/cloud/spanner/create_instance_request_builder.h b/google/cloud/spanner/create_instance_request_builder.h
index 7825af777301b..8b5c60d854497 100644
--- a/google/cloud/spanner/create_instance_request_builder.h
+++ b/google/cloud/spanner/create_instance_request_builder.h
@@ -17,6 +17,7 @@
 
 #include "google/cloud/spanner/instance.h"
 #include "google/cloud/spanner/version.h"
+#include <google/protobuf/util/message_differencer.h>
 #include <google/spanner/admin/instance/v1/spanner_instance_admin.pb.h>
 #include <map>
 #include <string>
@@ -46,6 +47,16 @@ class CreateInstanceRequestBuilder {
   CreateInstanceRequestBuilder& operator=(CreateInstanceRequestBuilder&&) =
       default;
 
+  friend bool operator==(CreateInstanceRequestBuilder const& a,
+                         CreateInstanceRequestBuilder const& b) noexcept {
+    return google::protobuf::util::MessageDifferencer::Equivalent(a.request_,
+                                                                  b.request_);
+  }
+  friend bool operator!=(CreateInstanceRequestBuilder const& a,
+                         CreateInstanceRequestBuilder const& b) noexcept {
+    return !(a == b);
+  }
+
   /**
    * Constructor requires Instance and Cloud Spanner instance config name.
    * The display_name is set to a default value of in.instance_id().
diff --git a/google/cloud/spanner/create_instance_request_builder_test.cc b/google/cloud/spanner/create_instance_request_builder_test.cc
index f9ca80b00781a..5b76892d75da6 100644
--- a/google/cloud/spanner/create_instance_request_builder_test.cc
+++ b/google/cloud/spanner/create_instance_request_builder_test.cc
@@ -22,6 +22,16 @@ namespace cloud {
 namespace spanner {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
 
+TEST(CreateInstanceRequestBuilder, Equality) {
+  Instance in(Project("test-project"), "test-instance");
+  CreateInstanceRequestBuilder b1(in, "c1");
+  CreateInstanceRequestBuilder b2(in, "c2");
+  EXPECT_NE(b1, b2);
+
+  b2 = b1;
+  EXPECT_EQ(b1, b2);
+}
+
 TEST(CreateInstanceRequestBuilder, DefaultValues) {
   Instance in(Project("test-project"), "test-instance");
   std::string expected_config =
diff --git a/google/cloud/spanner/update_instance_request_builder.h b/google/cloud/spanner/update_instance_request_builder.h
index e857f2b11e392..46ee9ba4654ac 100644
--- a/google/cloud/spanner/update_instance_request_builder.h
+++ b/google/cloud/spanner/update_instance_request_builder.h
@@ -18,6 +18,7 @@
 #include "google/cloud/spanner/instance.h"
 #include "google/cloud/spanner/version.h"
 #include <google/protobuf/util/field_mask_util.h>
+#include <google/protobuf/util/message_differencer.h>
 #include <google/spanner/admin/instance/v1/spanner_instance_admin.pb.h>
 #include <map>
 #include <string>
@@ -52,6 +53,16 @@ class UpdateInstanceRequestBuilder {
   UpdateInstanceRequestBuilder& operator=(UpdateInstanceRequestBuilder&&) =
       default;
 
+  friend bool operator==(UpdateInstanceRequestBuilder const& a,
+                         UpdateInstanceRequestBuilder const& b) noexcept {
+    return google::protobuf::util::MessageDifferencer::Equivalent(a.request_,
+                                                                  b.request_);
+  }
+  friend bool operator!=(UpdateInstanceRequestBuilder const& a,
+                         UpdateInstanceRequestBuilder const& b) noexcept {
+    return !(a == b);
+  }
+
   explicit UpdateInstanceRequestBuilder(std::string instance_name) {
     request_.mutable_instance()->set_name(std::move(instance_name));
   }
diff --git a/google/cloud/spanner/update_instance_request_builder_test.cc b/google/cloud/spanner/update_instance_request_builder_test.cc
index 154b6703713cb..85b55a6c8dfb0 100644
--- a/google/cloud/spanner/update_instance_request_builder_test.cc
+++ b/google/cloud/spanner/update_instance_request_builder_test.cc
@@ -42,6 +42,15 @@ TEST(UpdateInstanceRequestBuilder, Constructors) {
   EXPECT_EQ(expected_name, req.instance().name());
 }
 
+TEST(UpdateInstanceRequestBuilder, Equality) {
+  UpdateInstanceRequestBuilder b1("i1");
+  UpdateInstanceRequestBuilder b2("i2");
+  EXPECT_NE(b1, b2);
+
+  b2 = b1;
+  EXPECT_EQ(b1, b2);
+}
+
 TEST(UpdateInstanceRequestBuilder, AddLabels) {
   Instance in(Project("test-project"), "test-instance");
   std::string expected_name = in.FullName();