Split readme detection to separate function

src/Vervis/Readme.hs

@@ -35,6 +35,13 @@ import System.FilePath (isExtSeparator)
 import Vervis.Foundation (Widget)
 import Vervis.Render (renderSource)
 
+-- | Check if the given filename should be considered as README file. Assumes
+-- a flat filename which doesn't contain a directory part.
+isReadme :: Text -> Bool
+isReadme file =
+    let basename = takeWhile (not . isExtSeparator) file
+    in  toCaseFold "readme" == toCaseFold basename
+
 -- | Find a README file in a directory. Return the filename and the file
 -- content.
 findReadme :: Git -> Tree -> IO (Maybe (Text, ByteString))
@@ -43,8 +50,7 @@ findReadme git tree = go $ treeGetEnts tree
     go []                        = return Nothing
     go ((_perm, name, ref) : es) =
         let nameT = decodeUtf8With strictDecode $ toBytes name
-            base = takeWhile (not . isExtSeparator) nameT
-        in  if toCaseFold "readme" == toCaseFold base
+        in  if isReadme nameT
                 then do
                     obj <- getObject_ git ref True
                     case obj of