Refactor IO back out into Source and SemanticDiff

semantic-diff.cabal

@@ -49,7 +49,6 @@ library
                      , Renderer.SExpression
                      , Renderer.TOC
                      , SemanticDiff
-                     , SemanticDiff.IO
                      , SES
                      , Source
                      , SourceSpan

src/DiffCommand.hs

@@ -32,7 +32,6 @@ import Renderer.SExpression
 import Renderer.Split
 import Renderer.Summary
 import Renderer.TOC
-import SemanticDiff.IO
 import Source
 import Syntax
 import Term

src/ParseCommand.hs

@@ -24,7 +24,6 @@ import Text.Parser.TreeSitter.C
 import Text.Parser.TreeSitter.Go
 import Text.Parser.TreeSitter.JavaScript
 import Text.Parser.TreeSitter.Ruby
-import SemanticDiff.IO
 
 data ParseJSON = ParseJSON
   { category :: Text

src/SemanticDiff.hs

@@ -13,7 +13,9 @@ import qualified Renderer as R
 import Development.GitRev
 import DiffCommand
 import ParseCommand
-import SemanticDiff.IO
+import qualified Data.Text.IO as TextIO
+import System.IO
+import System.Environment (lookupEnv)
 
 main :: IO ()
 main = do
@@ -56,3 +58,18 @@ versionString = "semantic-diff version " <> showVersion Library.version <> " ("
 
 version :: Parser (a -> a)
 version = infoOption versionString (long "version" <> short 'V' <> help "output the version of the program")
+
+writeToOutput :: Maybe FilePath -> Text -> IO ()
+writeToOutput output text = case output of
+  Nothing -> do
+    setEncoding
+    TextIO.hPutStrLn stdout text
+  Just path -> withFile path WriteMode (`TextIO.hPutStr` text)
+  where
+    setEncoding = do
+      lang <- lookupEnv "LANG"
+      case lang of
+        -- If LANG is set and isn't the empty string, leave the encoding.
+        Just x | x /= "" -> pure ()
+        -- Otherwise default to utf8.
+        _ -> hSetEncoding stdout utf8

src/SemanticDiff/IO.hs

@@ -1,56 +0,0 @@
-module SemanticDiff.IO where
-
-import Prelude
-import Data.Text
-import qualified Data.Text.IO as TextIO
-import System.IO
-import System.Environment (lookupEnv)
-
-import Control.Exception (catch, IOException)
-import qualified Data.ByteString as B1
-import qualified Data.Text.ICU.Convert as Convert
-import qualified Data.Text.ICU.Detect as Detect
-
-import Source
-
-writeToOutput :: Maybe FilePath -> Text -> IO ()
-writeToOutput output text = case output of
-  Nothing -> do
-    setEncoding
-    TextIO.hPutStrLn stdout text
-  Just path -> withFile path WriteMode (`TextIO.hPutStr` text)
-
-  where
-    setEncoding = do
-      lang <- lookupEnv "LANG"
-      case lang of
-        -- If LANG is set and isn't the empty string, leave the encoding.
-        Just x | x /= "" -> pure ()
-        -- Otherwise default to utf8.
-        _ -> hSetEncoding stdout utf8
-
--- | Read the file and convert it to Unicode.
-readAndTranscodeFile :: FilePath -> IO Source
-readAndTranscodeFile path = do
-  size <- fileSize path
-  text <- case size of
-    0 -> pure B1.empty
-    _ -> B1.readFile path
-  transcode text
-
--- From https://github.com/haskell/bytestring/pull/79/files
-fileSize :: FilePath -> IO Integer
-fileSize f = withBinaryFile f ReadMode $ \h -> do
-  -- hFileSize fails if file is not regular file (like /dev/null). Catch
-  -- exception and try reading anyway.
-  filesz <- catch (hFileSize h) useZeroIfNotRegularFile
-  pure $ fromIntegral filesz `max` 0
-  where useZeroIfNotRegularFile :: IOException -> IO Integer
-        useZeroIfNotRegularFile _ = pure 0
-
--- | Transcode a file to a unicode source.
-transcode :: B1.ByteString -> IO Source
-transcode text = fromText <$> do
-  match <- Detect.detectCharset text
-  converter <- Convert.open match Nothing
-  pure $ Convert.toUnicode converter text

src/Source.hs

@@ -2,6 +2,7 @@
 {-# OPTIONS_GHC -funbox-strict-fields #-}
 module Source where
 
+import Prelude (FilePath, fromIntegral)
 import Prologue
 import qualified Data.ByteString as B
 import qualified Data.Text as T
@@ -9,6 +10,10 @@ import Numeric
 import Range
 import SourceSpan
 import Test.LeanCheck
+import System.IO
+import Control.Exception (catch, IOException)
+import qualified Data.Text.ICU.Convert as Convert
+import qualified Data.Text.ICU.Detect as Detect
 
 -- | The source, oid, path, and Maybe SourceKind of a blob in a Git repo.
 data SourceBlob = SourceBlob { source :: Source, oid :: T.Text, path :: FilePath, blobKind :: Maybe SourceKind }
@@ -22,12 +27,37 @@ newtype Source = Source { sourceText :: B.ByteString }
 data SourceKind = PlainBlob Word32  | ExecutableBlob Word32 | SymlinkBlob Word32
   deriving (Show, Eq)
 
+-- | Read the file and convert it to Unicode.
+readAndTranscodeFile :: FilePath -> IO Source
+readAndTranscodeFile path = do
+  size <- fileSize path
+  text <- case size of
+    0 -> pure B.empty
+    _ -> B.readFile path
+  transcode text
+
+-- From https://github.com/haskell/bytestring/pull/79/files
+fileSize :: FilePath -> IO Integer
+fileSize f = withBinaryFile f ReadMode $ \h -> do
+  -- hFileSize fails if file is not regular file (like /dev/null). Catch
+  -- exception and try reading anyway.
+  filesz <- catch (hFileSize h) useZeroIfNotRegularFile
+  pure $ fromIntegral filesz `max` 0
+  where useZeroIfNotRegularFile :: IOException -> IO Integer
+        useZeroIfNotRegularFile _ = pure 0
+
+-- | Transcode a file to a unicode source.
+transcode :: B.ByteString -> IO Source
+transcode text = fromText <$> do
+  match <- Detect.detectCharset text
+  converter <- Convert.open match Nothing
+  pure $ Convert.toUnicode converter text
+
 modeToDigits :: SourceKind -> Text
 modeToDigits (PlainBlob mode) = toS $ showOct mode ""
 modeToDigits (ExecutableBlob mode) = toS $ showOct mode ""
 modeToDigits (SymlinkBlob mode) = toS $ showOct mode ""
 
-
 -- | The default plain blob mode
 defaultPlainBlob :: SourceKind
 defaultPlainBlob = PlainBlob 0o100644

test/IntegrationSpec.hs

@@ -14,7 +14,6 @@ import Renderer
 import Renderer.SExpression as Renderer
 import Source
 import DiffCommand
-import SemanticDiff.IO (readAndTranscodeFile)
 import System.FilePath
 import System.FilePath.Glob
 import Test.Hspec (Spec, describe, it, SpecWith, runIO, parallel)

test/TOCSpec.hs

@@ -10,7 +10,6 @@ import Data.Record
 import Data.String
 import Diff
 import DiffCommand
-import SemanticDiff.IO (readAndTranscodeFile)
 import Info
 import Interpreter
 import ParseCommand