testify: assert.Equal fails OoM when comparing protos

[yuryu]

What happened:
This is not yet merged, but I'm leaving it as a caution to future developers.

When comparing two values containing protos, testify goes in an infinite loop and eventually dies oom.
Expressions like

assert.Equal(t, expected.Properties, actual.Properties)

do not work when there are diffs.
See related bugs here:

• Out of memory error on comparing protobuf types stretchr/testify#930
• Code generated from proto files breaks unit tests cilium/cilium#12772
  This is likely a bug in an underlying library go-spew (spew fails to detect cyclic data davecgh/go-spew#66) but it seems to be abandoned (Is this lib abandoned? davecgh/go-spew#128).

So... until there is a fix, we need to have a workaround.

What you expected to happen:
assert.Equal compares two values, outputs diffs if there is any, and returns.

How to reproduce it (as minimally and precisely as possible):
If I change assertEqualRecord as follows in open-saves_test.go, it fails.

func assertEqualRecord(t *testing.T, expected, actual *pb.Record) {
	t.Helper()
	if expected == nil {
		assert.Nil(t, actual)
		return
	}
	if assert.NotNil(t, actual) {
		assert.Equal(t, expected.Key, actual.Key)
		assert.Equal(t, expected.Blob, actual.Blob)
		assert.Equal(t, expected.BlobSize, actual.BlobSize)
		assert.ElementsMatch(t, expected.Tags, actual.Tags)
		assert.Equal(t, expected.OwnerId, actual.OwnerId)
		assert.Equal(t, expected.Properties, actual.Properties)
		assertTimestampsWithinDelta(t, expected.GetCreatedAt(), actual.GetCreatedAt())
		assertTimestampsWithinDelta(t, expected.GetUpdatedAt(), actual.GetUpdatedAt())
	}
}

Anything else we need to know?:

Environment:

• Open Saves version:
• Kubernetes version (use kubectl version):
• Cloud provider or hardware configuration:
• Install method (yaml/helm):
• Troubleshooting guide log(s):
• Others: