Edge cases mode ignored for lists

[jdmarble]

Testing Problem

I'm getting many thousands of lines of warnings logged per test if I generate a list of objects with lots of edge cases. This happens despite setting edgeCases = EdgeCasesMode.NONE on the @Property and defaultEdgeCases = NONE in jqwik.properties.

See this revised gist for a minimal example. Output:

Aug 30, 2020 2:22:58 PM net.jqwik.engine.facades.EdgeCasesFacadeImpl logTooManyEdgeCases
WARNING: Combinatorial explosion of edge case generation. Stopped creating more after 10000 generated cases.
// exactly 10k-2 lines skipped 
Aug 30, 2020 2:23:15 PM net.jqwik.engine.facades.EdgeCasesFacadeImpl logTooManyEdgeCases
WARNING: Combinatorial explosion of edge case generation. Stopped creating more after 10000 generated cases.
timestamp = 2020-08-30T14:23:15.227451100, ThingTest:my property = 
                              |--------------------jqwik--------------------
tries = 1000                  | # of calls to property
checks = 1000                 | # of not rejected calls
generation = RANDOMIZED       | parameters are randomly generated
after-failure = PREVIOUS_SEED | use the previous seed
edge-cases#mode = NONE        | edge cases are not explicitly generated
seed = 4337682503445002671    | random seed to reproduce generated values

Suggested Solution

I think the intent was to make edgeCases = EdgeCasesMode.NONE work on lists, but it's not working as intended. Perhaps an oversite or bug is preventing the setting from propagating through list generation.

Discussion

I'm not sure if my build is slowing down because of the edge case generation or the added logging.

[jlink]

That’s a lot of log lines :-(

I’ll look at it when I’m back from holidays in two weeks.

[jlink]

@jdmarble Do you have a property handy that reproduces the explosion of log lines? Need not necessarily be 10k lines, just a few would suffice ;-)

[jlink]

Don't worry. I just noticed the gist.

[jlink]

BTW, If I remove edgeCases = EdgeCasesMode.NONE I only get 4 lines of warning. AND the tests runs faster probably due to saving all the synchronized log output.

[jlink]

To (partially) explain this behaviour: edgeCases = EdgeCasesMode.NONE only applies to the combined edge case generation of all parameters. Individual generators will always (as of version 1.3.5) inject edge cases. This is not really consistent and I'm thinking about getting rid of this inconsistency but it requires deeper refactoring.

[jlink]

I was wrong again :-(

edgeCases = EdgeCasesMode.NONE suppresses generation of non edge cases "on my machine" since I use edgeCases = EdgeCasesMode.FIRST as default. So ignore my previous comment.

[jlink]

I changed two things:

• The warning about combinatorial explosion will only be logged max once per property
• I reduced the max number of edge cases to be generated to 1000, which cuts the runtime of your property considerably

The changes are already available in 1.3.6-SNAPSHOT

I'll probably do a significant change to how edge cases will be generated in the more recent future. Maybe already for the 1.3.6 release but maybe not.

[jdmarble]

Thank you so much! With 1.3.6, I've finally been able to upgrade from 1.2.7.