Is your feature request related to a problem? Please describe.
Right now when my state differs from what I expect in bloc tests I get a big load of text on my screen showing what expected and actual states look like. The problem is, sometimes my state contains many items or the item itself is very big. It's REALLY hard to read it.

Describe the solution you'd like
I can see two solutions:

• Showing a diff as GitHub does.
• Outputting only the parts of the object that really differed. So that when I have some object as a state, but only 2 out of 25 fields differ, I'd only care to see those two fields' values instead of the whole object.

Describe alternatives you've considered
Right now I just copy&paste both expected and actual states to some diff checker online to see the difference.

Additional context
Find difference with your eye :)