From 687a34548ce19678e5c3c9332db413106db4d7d0 Mon Sep 17 00:00:00 2001 From: Richard Feldman Date: Wed, 12 Jul 2017 11:58:15 -0400 Subject: [PATCH] Incorporate hash of first description into seed. Fixes #192 --- elm-package.json | 1 + src/Test/Runner.elm | 78 +++++++++++++++++++++++++++++++++--------- tests/elm-package.json | 1 + 3 files changed, 64 insertions(+), 16 deletions(-) diff --git a/elm-package.json b/elm-package.json index 31168bb..fda3ee2 100644 --- a/elm-package.json +++ b/elm-package.json @@ -13,6 +13,7 @@ "Fuzz" ], "dependencies": { + "Skinney/fnv": "1.0.4 <= v < 2.0.0", "elm-community/lazy-list": "1.0.0 <= v < 2.0.0", "elm-community/shrink": "2.0.0 <= v < 3.0.0", "elm-lang/core": "5.0.0 <= v < 6.0.0", diff --git a/src/Test/Runner.elm b/src/Test/Runner.elm index 90c5add..b52f7e0 100644 --- a/src/Test/Runner.elm +++ b/src/Test/Runner.elm @@ -41,6 +41,7 @@ These functions give you the ability to run fuzzers separate of running fuzz tes -} import Expect exposing (Expectation) +import FNV import Fuzz exposing (Fuzzer) import Lazy.List as LazyList exposing (LazyList) import Random.Pcg as Random @@ -209,7 +210,12 @@ Some design notes: -} distributeSeeds : Int -> Random.Seed -> Test -> Distribution -distributeSeeds runs seed test = +distributeSeeds = + distributeSeedsHelp False + + +distributeSeedsHelp : Bool -> Int -> Random.Seed -> Test -> Distribution +distributeSeedsHelp hashed runs seed test = case test of Internal.UnitTest run -> { seed = seed @@ -230,22 +236,62 @@ distributeSeeds runs seed test = } Internal.Labeled description subTest -> - let - next = - distributeSeeds runs seed subTest - in - { seed = next.seed - , all = List.map (Labeled description) next.all - , only = List.map (Labeled description) next.only - , skipped = List.map (Labeled description) next.skipped - } + -- This fixes https://github.com/elm-community/elm-test/issues/192 + -- The first time we hit a Labeled, we want to use the hash of + -- that label, along with the original seed, as our starting + -- point for distribution. Repeating this process more than + -- once would be a waste. + if hashed then + let + next = + distributeSeedsHelp True runs seed subTest + in + { seed = next.seed + , all = List.map (Labeled description) next.all + , only = List.map (Labeled description) next.only + , skipped = List.map (Labeled description) next.skipped + } + else + let + intFromSeed = + -- At this point, this seed will be the original + -- one passed into distributeSeeds. We know this + -- because the only other branch that does a + -- Random.step on that seed is the Internal.Test + -- branch, and you can't have a Labeled inside a + -- Test, so that couldn't have come up yet. + seed + -- Convert the Seed back to an Int + |> Random.step (Random.int 0 Random.maxInt) + |> Tuple.first + + hashedSeed = + -- Incorporate the originally passed-in seed + (toString intFromSeed ++ description) + -- Hash from String to Int + |> FNV.hashString + -- Convert Int back to Seed + |> Random.initialSeed + + next = + distributeSeedsHelp True runs hashedSeed subTest + in + -- Using seed instead of next.seed fixes https://github.com/elm-community/elm-test/issues/192 + -- by making it so that all the tests underneath this Label begin + -- with the hashed seed, but subsequent sibling tests in this Batch + -- get the same seed as before. + { seed = seed + , all = List.map (Labeled description) next.all + , only = List.map (Labeled description) next.only + , skipped = List.map (Labeled description) next.skipped + } Internal.Skipped subTest -> let -- Go through the motions in order to obtain the seed, but then -- move everything to skipped. next = - distributeSeeds runs seed subTest + distributeSeedsHelp hashed runs seed subTest in { seed = next.seed , all = [] @@ -256,20 +302,20 @@ distributeSeeds runs seed test = Internal.Only subTest -> let next = - distributeSeeds runs seed subTest + distributeSeedsHelp hashed runs seed subTest in -- `only` all the things! { next | only = next.all } Internal.Batch tests -> - List.foldl (batchDistribute runs) (emptyDistribution seed) tests + List.foldl (batchDistribute hashed runs) (emptyDistribution seed) tests -batchDistribute : Int -> Test -> Distribution -> Distribution -batchDistribute runs test prev = +batchDistribute : Bool -> Int -> Test -> Distribution -> Distribution +batchDistribute hashed runs test prev = let next = - distributeSeeds runs prev.seed test + distributeSeedsHelp hashed runs prev.seed test in { seed = next.seed , all = prev.all ++ next.all diff --git a/tests/elm-package.json b/tests/elm-package.json index 7e54199..c9081c3 100644 --- a/tests/elm-package.json +++ b/tests/elm-package.json @@ -9,6 +9,7 @@ ], "exposed-modules": [], "dependencies": { + "Skinney/fnv": "1.0.4 <= v < 2.0.0", "elm-community/lazy-list": "1.0.0 <= v < 2.0.0", "elm-community/shrink": "2.0.0 <= v < 3.0.0", "elm-lang/core": "5.0.0 <= v < 6.0.0",