Introduce hspec-megaparsec

Fixes #13.

tests/Test/KitchenSinkSpec.hs

@@ -6,19 +6,13 @@ module Test.KitchenSinkSpec
 
 import qualified Data.Text.IO as Text.IO
 import qualified Data.Text.Lazy.IO as Text.Lazy.IO
+import qualified Data.Text.Lazy as Lazy (Text)
 import qualified Language.GraphQL.Encoder as Encoder
 import qualified Language.GraphQL.Parser as Parser
 import Paths_graphql (getDataFileName)
-import Test.Hspec ( Spec
-                  , describe
-                  , it
-                  )
-import Test.Hspec.Expectations ( expectationFailure
-                               , shouldBe
-                               )
-import Text.Megaparsec ( errorBundlePretty
-                       , parse
-                       )
+import Test.Hspec (Spec, describe, it)
+import Test.Hspec.Megaparsec (parseSatisfies)
+import Text.Megaparsec (parse)
 import Text.RawString.QQ (r)
 
 spec :: Spec
@@ -26,17 +20,12 @@ spec = describe "Kitchen Sink" $ do
     it "minifies the query" $ do
         dataFileName <- getDataFileName "tests/data/kitchen-sink.graphql"
         minFileName <- getDataFileName "tests/data/kitchen-sink.min.graphql"
-        actual <- Text.IO.readFile dataFileName
         expected <- Text.Lazy.IO.readFile minFileName
 
-        either
-            (expectationFailure . errorBundlePretty)
-            (flip shouldBe expected . Encoder.document Encoder.minified)
-            $ parse Parser.document dataFileName actual
+        shouldNormalize Encoder.minified dataFileName expected
 
     it "pretty prints the query" $ do
         dataFileName <- getDataFileName "tests/data/kitchen-sink.graphql"
-        actual <- Text.IO.readFile dataFileName
         let expected = [r|query queryName($foo: ComplexType, $site: Site = MOBILE) {
   whoever123is: node(id: [123, 456]) {
     id
@@ -70,7 +59,11 @@ fragment frag on Friend {
 }
 |]
 
-        either
-            (expectationFailure . errorBundlePretty)
-            (flip shouldBe expected . Encoder.document Encoder.pretty)
-            $ parse Parser.document dataFileName actual
+        shouldNormalize Encoder.pretty dataFileName expected
+
+shouldNormalize :: Encoder.Formatter -> FilePath -> Lazy.Text -> IO ()
+shouldNormalize formatter dataFileName expected = do
+    actual <- Text.IO.readFile dataFileName
+    parse Parser.document dataFileName actual `parseSatisfies` condition
+      where
+        condition = (expected ==) . Encoder.document formatter