Test Util.groupBy

test/Unused/UtilSpec.hs

@@ -0,0 +1,29 @@
+module Unused.UtilSpec
+    ( main
+    , spec
+    ) where
+
+import Test.Hspec
+import Unused.Util
+
+data Person = Person
+    { pName :: String
+    , pAge :: Int
+    } deriving (Eq, Show)
+
+main :: IO ()
+main = hspec spec
+
+spec :: Spec
+spec = parallel $
+    describe "groupBy" $ do
+        it "groups by the result of a function" $ do
+            let numbers = [1..10] :: [Int]
+
+            groupBy ((0 ==) . flip mod 2) numbers `shouldBe` [(False, [1, 3, 5, 7, 9]), (True, [2, 4, 6, 8, 10])]
+
+        it "handles records" $ do
+            let people = [Person "Jane" 10, Person "Jane" 20, Person "John" 20]
+
+            groupBy pName people `shouldBe` [("Jane", [Person "Jane" 10, Person "Jane" 20]), ("John", [Person "John" 20])]
+            groupBy pAge people `shouldBe` [(10, [Person "Jane" 10]), (20, [Person "Jane" 20, Person "John" 20])]

unused.cabal

@@ -73,6 +73,7 @@ test-suite unused-test
                      , Unused.LikelihoodCalculatorSpec
                      , Unused.Grouping.InternalSpec
                      , Unused.TermSearch.InternalSpec
+                     , Unused.UtilSpec
   ghc-options:         -threaded -rtsopts -with-rtsopts=-N -Wall -Werror
   default-language:    Haskell2010