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When writing about Property-Based testing, I found they were much more solid and comprehensive than usual tests, due to their more general (properties vs examples). They weren’t used because they felt more complex and time-intensive to write, despite being shorter and having to change them less.

Nathan

@natfu.be

I've read a couple papers on property based testing and the examples are usually very DS&A oriented because it's where testing invariants and defining properties is easy. For business rules it's much more difficult to pin down exact behavior. Requirements might not be precise enough.

18/1/26, 5:57 pm0 reposts1 like

Fred Hebert

@ferd.ca

18 Jan

Yeah the invariant-based stuff has somewhat low ceilings in what you can do, but stateful properties have an incredible amount of expressiveness for larger scale integration tests around whole workflows that would in theory be very powerful as a backstop for LLM-based development.

Nathan

@natfu.be

18 Jan

Do you mean something like this? antithesis.com/resources/de... by "stateful properties"?

antithesis.comDeterministic Simulation Testing (DST) - Debugging with perfect reproducibilityDiscover how deterministic simulation testing works, how to integrate it into your stack, and what kinds of systems benefit most. Real-world case studies included.

Fred Hebert

@ferd.ca

18 Jan

Yeah that should cover some. I also had propertesting.com/book_case_st... as a book chapter that shows testing CRUD operations and transactions in a DB as a relatively small suite, and then supports parallel testing.

propertesting.comCase Study: Stateful Properties with a BookstoreA book on Property-based Testing

Gordon Guthrie

@foundationsofthedigitalstate.com

18 Jan

my favourite property based testing is Identity diff and patch for example A = diff(B, C) therefore C = patch(A, B) generate a million sets of B and C and you are away obvs there arent always Identities lying around but when there are - did 8m tests at bet365 based on recording and playback

alias (in chains)

@antiali.as

18 Jan

Can you link to some sources on what you mean by stateful properties?

Fred Hebert

@ferd.ca

18 Jan

Here’s a book chapter I had written about it: propertesting.com/book_case_st... The model for execution is described at a higher level in propertesting.com/book_statefu...

propertesting.comCase Study: Stateful Properties with a BookstoreA book on Property-based Testing

alias (in chains)

@antiali.as

18 Jan

If I’m understanding quickly, testing by generating arbitrary reified operations and applying them to both a target system and a dual model of the system, then asserting some observations, is that close?