Fixed an issue where JSON parsing of SaveFormat was overly restrictive (#42)

Author: LaurentRDC

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 pandoc-plot uses [Semantic Versioning](http://semver.org/spec/v2.0.0.html)
 
+## Release 1.4.2
+
+* Fixed an issue where the parsing of default save format from configuration was overly restrictive (#42).
+
 ## Release 1.4.1
 
 * Don't automatically defer javascript scripts when creating interactive figures (#39).

src/Text/Pandoc/Filter/Plot/Monad/Types.hs

@@ -34,8 +34,8 @@ where
 import Data.Char (toLower)
 import Data.List (intersperse)
 import Data.String (IsString (..))
-import Data.Text (Text, pack)
-import Data.Yaml (FromJSON, ToJSON (toJSON))
+import Data.Text (Text, pack, unpack)
+import Data.Yaml (FromJSON(..), ToJSON (toJSON), withText)
 import GHC.Generics (Generic)
 import System.FilePath (splitFileName)
 import System.Info (os)
@@ -229,12 +229,16 @@ instance IsString SaveFormat where
         mconcat
           [ s,
             " is not one of the valid save formats : ",
-            mconcat $ intersperse ", " $ show <$> saveFormats
+            mconcat $ intersperse ", " $ show <$> saveFormats,
+            " (and lowercase variations). "
           ]
     where
       saveFormats = enumFromTo minBound maxBound :: [SaveFormat]
 
-instance FromJSON SaveFormat
+-- | Use the IsString instance to parse JSON so that the parsing is flexible
+-- with respect to uppercase/lowercase (#42)
+instance FromJSON SaveFormat where
+  parseJSON = withText "SaveFormat" (pure . fromString . unpack)
 
 instance ToJSON SaveFormat where
   toJSON = toJSON . extension