Add meat to the test

test/core/channel/channelz_registry_test.cc

@@ -27,6 +27,7 @@
 #include "src/core/lib/channel/channel_trace.h"
 #include "src/core/lib/channel/channelz_registry.h"
 #include "src/core/lib/gpr/useful.h"
+#include "src/core/lib/gprpp/memory.h"
 #include "src/core/lib/iomgr/exec_ctx.h"
 #include "src/core/lib/json/json.h"
 
@@ -41,7 +42,76 @@ namespace testing {
 
 // Tests basic ChannelTrace functionality like construction, adding trace, and
 // lookups by uuid.
-TEST(ChannelzRegistryTest, BasicTest) {}
+TEST(ChannelzRegistryTest, UuidStartsAboveZeroTest) {
+  int object_to_register;
+  intptr_t uuid = ChannelzRegistry::Default()->Register(&object_to_register);
+  ASSERT_GT(uuid, 0) << "First uuid chose must be greater than zero. Zero if "
+                        "reserved according to "
+                        "https://github.com/grpc/proposal/blob/master/"
+                        "A14-channelz.md";
+  ChannelzRegistry::Default()->Unregister(uuid);
+}
+
+TEST(ChannelzRegistryTest, UuidsAreIncreasing) {
+  int object_to_register;
+  std::vector<intptr_t> uuids;
+  for (int i = 0; i < 10; ++i) {
+    // reregister the same object. It's ok since we are just testing uuids
+    uuids.push_back(ChannelzRegistry::Default()->Register(&object_to_register));
+  }
+  for (size_t i = 1; i < uuids.size(); ++i) {
+    ASSERT_LT(uuids[i - 1], uuids[i]) << "Uuids must always be increasing";
+  }
+}
+
+TEST(ChannelzRegistryTest, RegisterGetTest) {
+  int object_to_register = 42;
+  intptr_t uuid = ChannelzRegistry::Default()->Register(&object_to_register);
+  int* retrieved = ChannelzRegistry::Default()->Get<int>(uuid);
+  ASSERT_EQ(object_to_register, *retrieved);
+  ASSERT_EQ(&object_to_register, retrieved);
+}
+
+TEST(ChannelzRegistryTest, MultipleTypeTest) {
+  int int_to_register = 42;
+  intptr_t int_uuid = ChannelzRegistry::Default()->Register(&int_to_register);
+  std::string str_to_register = "hello world";
+  intptr_t str_uuid = ChannelzRegistry::Default()->Register(&str_to_register);
+  int* retrieved_int = ChannelzRegistry::Default()->Get<int>(int_uuid);
+  std::string* retrieved_str =
+      ChannelzRegistry::Default()->Get<std::string>(str_uuid);
+  ASSERT_EQ(int_to_register, *retrieved_int);
+  ASSERT_EQ(&int_to_register, retrieved_int);
+  ASSERT_STREQ(str_to_register.c_str(), (*retrieved_str).c_str());
+  ASSERT_EQ(&str_to_register, retrieved_str);
+}
+
+namespace {
+class Foo {
+ public:
+  int bar;
+};
+}  // namespace
+
+TEST(ChannelzRegistryTest, CustomObjectTest) {
+  Foo* foo = New<Foo>();
+  foo->bar = 1024;
+  intptr_t uuid = ChannelzRegistry::Default()->Register(foo);
+  Foo* retrieved = ChannelzRegistry::Default()->Get<Foo>(uuid);
+  ASSERT_EQ(foo, retrieved);
+  ASSERT_EQ(foo->bar, retrieved->bar);
+}
+
+TEST(ChannelzRegistryTest, NullIfNotPresentTest) {
+  int object_to_register = 42;
+  intptr_t uuid = ChannelzRegistry::Default()->Register(&object_to_register);
+  // try to pull out a uuid that does not exist.
+  int* nonexistant = ChannelzRegistry::Default()->Get<int>(1234);
+  ASSERT_EQ(nonexistant, nullptr);
+  int* retrieved = ChannelzRegistry::Default()->Get<int>(uuid);
+  ASSERT_EQ(object_to_register, *retrieved);
+  ASSERT_EQ(&object_to_register, retrieved);
+}
 
 }  // namespace testing
 }  // namespace grpc_core