Create unit test for Util module

test/UtilSpec.hs

@@ -0,0 +1,63 @@
+module UtilSpec where
+
+import Prelude hiding (head)
+import Test.Hspec
+import Util
+
+import Data.Word
+import Data.Char (chr)
+
+spec :: Spec
+spec = do
+  describe "toLowerCase" $ do
+    it "converts arbitrary string to lowercase" $
+      toLowerCase "Some UpPeR CASED sTRi_NG" `shouldBe` "some upper cased stri_ng"
+    it "does not convert already lowercased string" $
+      toLowerCase "some lower cased string" `shouldBe` "some lower cased string"
+  
+  describe "byteStr" $ do
+    it "presents byte as hex" $ do
+      let input    = [0,    1,    5,    10,   15,   16,   255 ] :: [Word8]
+      let expected = ["00", "01", "05", "0a", "0f", "10", "ff"]
+      map byteStr input `shouldBe` expected
+
+  describe "bytesStr" $ do
+    it "presents bytes as hex in fixed columns of width 5" $ do
+      let input    = [0..19] :: [Word8]
+      let expected = "00 01 02 03 04 \n\
+                     \05 06 07 08 09 \n\
+                     \0a 0b 0c 0d 0e \n\
+                     \0f 10 11 12 13"                
+      bytesStr 5 input `shouldBe` expected
+
+  describe "head" $ do
+    it "returns just a head of list" $ do
+      head [4, 3, 6] `shouldBe` (Just 4 :: Maybe Int)
+    it "returns Nothing if list is empty" $ do
+      head [] `shouldBe` (Nothing :: Maybe Int)
+
+  describe "unescape" $ do
+    it "properly converts escape sequences to correct ASCII characters" $ do
+      let input = "\\tHello,\\nworld!\\0"
+      let expected = "\tHello,\nworld!\0"
+      unescape input `shouldBe` Just expected
+    it "supports all escape sequences" $ do
+      let input = "\\n\\t\\v\\b\\r\\f\\a\\\\\\\"\\0"
+      let expected = map chr [10, 9, 11, 8, 13, 12, 7, 92, 34, 0]
+      unescape input `shouldBe` Just expected
+    it "returns nothing if unknown escape sequence encountered" $ do
+      let input = "Unknown escape: \\x"
+      unescape input `shouldBe` Nothing
+  
+  describe "explode" $ do
+    it "splits the list by given character" $ do
+      let input = "hello:world: what's : up?"
+      let expected = ["hello", "world", " what's ", " up?"]
+      explode (==':') input `shouldBe` expected
+    it "supports empty input" $ do
+      let input = ""      
+      explode (==':') input `shouldBe` []
+    it "filters out empty lists" $ do
+      let input = ":hello:world:::::: what's : up?"
+      let expected = ["hello", "world", " what's ", " up?"]
+      explode (==':') input `shouldBe` expected