Generate special values for f32 and f64 #183
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As soon as they are exactly the same
The reason to make it more probable is: Imagine a user would test function accepting two float arguments. By default quickcheck runs each test 100 times. Probability of special value generation (lets say 0.0) after this change is 1 of 100. Then probability of two 0.0 generation is 1 of 10000 which (simplifying) means that tests should be run 100 times. If we run tests on per commit basis then 100 commits should be made - pretty realistic number. If we leave it as it was before with probability 1 of 1000, it would mean that would "require" to commit 10000 times (again, simplifying) to make two 0.0 appear. PS: Doesn't totally solve the problem. Function accepting 3 floats will still require to run tests 10000 times to get three 0.0
bekh6ex
commented
Sep 26, 2017
| for _ in 0..10000 { | ||
| let f = f32::arbitrary(&mut gen); | ||
| if !f.is_finite() { | ||
| non_finite_was_found = true; |
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This test can theoretically create a false negative, but probability of that is (as far as I've managed to calculate) 1 of 500.
Maybe number of iterations should be increased, should it?
BurntSushi
requested changes
Nov 28, 2017
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Sorry for taking so long to respond to this. I looked into merging this PR, but it's making a lot of changes and adding a new config knob. I would like to move discussion of how we approach this back to #27 --- Could you please sketch out an implementation path and motivate it? Adding new knobs for this isn't ideal. It'd be nice if we just did the right thing.
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Closing due to inactivity. |
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Issue #27