Parse and serialize rules.json

TL;DR:
- Write FromJSON instances to decode rules.json file
- Prefer Text to String and use the OverloadedStrings language extension
- Read /etc/hosts and append the serialized rules.json to the end

Notes:
- I can remove some of the FromJSON instances and use GHC Generics to define
  them for me.

TODO:
- Define the systemd timer unit for this to run
- Ensure script can run with root privileges

tools/website-blocker/Spec.hs

@@ -0,0 +1,38 @@
+module Spec (main) where
+
+--------------------------------------------------------------------------------
+-- Dependencies
+--------------------------------------------------------------------------------
+
+import qualified Main as Main
+
+import Test.Hspec
+
+--------------------------------------------------------------------------------
+-- Tests
+--------------------------------------------------------------------------------
+
+main :: IO ()
+main = hspec $ do
+  describe "getRules" $ do
+    it "returns the parsed rules from rules.json" $ do
+      rules <- Main.getRules
+      rules `shouldBe` [ Main.Rule { Main.urls = [ Main.URL "facebook.com"
+                                                 , Main.URL "www.facebook.com"
+                                                 , Main.URL "twitter.com"
+                                                 , Main.URL "www.twitter.com"
+                                                 , Main.URL "youtube.com"
+                                                 , Main.URL "www.youtube.com"
+                                                 , Main.URL "instagram.com"
+                                                 , Main.URL "www.instagram.com"
+                                                 ]
+                                   , Main.allowed = []
+                                   }
+                       , Main.Rule { Main.urls = [ Main.URL "chat.googleplex.com" ]
+                                   , Main.allowed = []
+                                   }
+                       ]
+
+  describe "Prelude.head" $ do
+    it "returns the first element of a list" $ do
+      head [23 ..] `shouldBe` (23 :: Int)