Add safe proto diff helper

[eric846]

Need to do this separately after test/adaptive_load/utility.h goes in.

The helper should do:
EXPECT_EQ(message->DebugString(), expected_config.DebugString());
EXPECT_TRUE(Envoy::MessageUtil()(*message, expected_config));

oschaaf:
I learned that with proto3 default values may not get serialised. I'm not 100% sure that equivalence here guarantees actual equivalence with respect to set/not-set/default-value. Therefore, to make sure no edge cases slip past, maybe it makes sense to also double down with MessageUtil()(message1, message1). This won't produce a helpful test message, so I'd put it after comparing the debug strings (which should produce a nice diff), maybe in a helper method.

[eric846]

Actually this isn't specific to adaptive_load, could go in an existing file.

[eric846]

Actually I don't see an existing file to put it in, will handle this after all these PRs are done.

[eric846]

This may be clearer than the construct with MessageUtil():

  EXPECT_TRUE(::Envoy::Protobuf::util::MessageDifferencer::Equivalent(*empty_config, expected_config));

[oschaaf]

Oh that's much nicer indeed

[oschaaf]

In the context of this issue, also making a note of a helpful review comment by @mum4k [1].
TIL there's ::testing::EqualsProto
Sounds like we may want to use that as a replacement where applicable?

[1] #522 (comment)

[mum4k]

Interestingly enough, testing::EqualsProto looks to be internal only:

google/googletest#1761

While it is in the public documentation of gtest and gmock, it isn't actually present in the code. So back to plan B.

[mum4k]

Fyi, we now have a proto matcher:

nighthawk/test/test_common/proto_matchers.h

Lines 40 to 48 in 9a6d718

	// Compares two proto messages for equality.
	// Prints diff on failures.
	//
	// Example use:
	// proto2::Message actual_proto;
	// proto2::Message expected_proto;
	//
	// EXPECT_THAT(actual_proto, EqualsProto(expected_proto));
	MATCHER_P(EqualsProto, expected_proto, "is equal to the expected_proto") {

[eric846]

\o/

…

On Wed, Aug 18, 2021 at 6:08 PM Jakub Sobon ***@***.***> wrote: Fyi, we now have a proto matcher: https://github.com/envoyproxy/nighthawk/blob/9a6d7181ad886d9ad00a769c7d667d07ca2dc5dc/test/test_common/proto_matchers.h#L40-L48 — You are receiving this because you modified the open/close state. Reply to this email directly, view it on GitHub <#433 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ANPRQMN7LU72A6VCY6BKI7LT5QVMZANCNFSM4PTV7OEA> .