Introduce formatter type for the encoder

... to distinguish between minified and pretty printing.

tests/Test/KitchenSinkSpec.hs

@@ -1,3 +1,5 @@
+{-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE QuasiQuotes #-}
 module Test.KitchenSinkSpec
     ( spec
     ) where
@@ -16,10 +18,11 @@ import Test.Hspec.Expectations ( expectationFailure
 import Text.Megaparsec ( errorBundlePretty
                        , parse
                        )
+import Text.RawString.QQ (r)
 
 spec :: Spec
-spec = describe "Kitchen Sink" $
-    it "prints the query" $ do
+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
@@ -27,5 +30,46 @@ spec = describe "Kitchen Sink" $
 
         either
             (expectationFailure . errorBundlePretty)
-            (flip shouldBe expected . Encoder.document)
+            (flip shouldBe expected . Encoder.document Encoder.Minified)
+            $ parse Parser.document dataFileName actual
+
+    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
+... on User@defer{
+field2{
+id
+alias:field1(first:10,after:$foo)@include(if:$foo){
+id
+...frag
+}
+}
+}
+}
+}
+
+mutation likeStory{
+like(story:123)@defer{
+story{
+id
+}
+}
+}
+
+fragment frag on Friend{
+foo(size:$size,bar:$b,obj:{key:"value"})
+}
+
+{
+unnamed(truthy:true,falsey:false)
+query
+}
+|]
+
+        either
+            (expectationFailure . errorBundlePretty)
+            (flip shouldBe expected . Encoder.document (Encoder.Pretty 0))
             $ parse Parser.document dataFileName actual