flake: Attempt to run doctests

Reviewed-by: Alexander Kobjolke <me@failco.de>

test/spec/HCatSpec.hs

@@ -0,0 +1,27 @@
+-- {-# LANGUAGE GHC2021 #-}
+
+module HCatSpec (spec) where
+
+import HCat.Internal (chunksOf, parseArgs)
+
+import Test.Hspec
+import Test.Hspec.QuickCheck (prop)
+import Test.QuickCheck (Positive (getPositive))
+
+spec :: Spec
+spec = do
+  describe "parseArgs" do
+    it "returns the filename if given a single argument" do
+      parseArgs ["foo"] `shouldBe` Right "foo"
+      parseArgs [] `shouldBe` Left "No filename given!"
+      parseArgs ["foo", "bar"] `shouldBe` Left "Only a single file is supported"
+  describe "chunksOf" $ do
+    prop "each chunk contains at most N items" $ \n xs ->
+      let chunkLengths = length <$> chunksOf n (xs :: [Int])
+       in case chunkLengths of
+            [] -> pure ()
+            ns -> maximum ns `shouldSatisfy` (<= n)
+
+    prop "the sum of all lengths is equal to the length of the input" $ \n xs ->
+      let chunkLengths = length <$> chunksOf (getPositive n) (xs :: [Int])
+       in sum chunkLengths `shouldBe` length xs

test/spec/Spec.hs

@@ -0,0 +1 @@
+{-# OPTIONS_GHC -F -pgmF hspec-discover #-}