HEAD BROKEN: Update EntitySerializationTest to reflect actual Serializer setup

I like the test helper! This makes the tests much easier to read.

+++ b/core/modules/serialization/lib/Drupal/serialization/Tests/SerializationTestSetupHelper.phpundefined
@@ -0,0 +1,101 @@
+  protected function encoders() {
...
+  protected function normalizers() {

This looks confusing in the constructor, maybe we can just change the names of these to initEncoders/initNormalizers?

Lin, are you picking this one up? If not, I am happy to do this today.

We can actually convert these tests to use DrupalUnitTestBase too, so let's try that. It worked fine, apart from the default_langcode, which I have changed the expected data for.

I actually checked this normally, outside of tests, and it matches the structure that I have changed the expected data to in the test. SO I'm inclined to think this might be right. What do you think?

Cuts the text runs from ~10 secs to ~3 secs, not bad!

Just another reroll now that we are in the serialization module.

Good point, thanks for the review.

Committed/pushed to 8.x, thanks!

Because of #1891516: Remove $install parameter from DrupalUnitTestBase::enableModules(), encourage individual schema tables this is broken, fixing now.

Passes locally.

Committed/pushed the follow-up, whoopsie that one was definitely me since I committed the DUTB patch yesterday...