Collect hash during creating an archive

lib/SlackBuilder/Download.hs

@@ -2,6 +2,7 @@
    v. 2.0. If a copy of the MPL was not distributed with this file, You can
    obtain one at https://mozilla.org/MPL/2.0/. -}
 
+-- | Contains routines for downloading, cloning and uploading sources.
 module SlackBuilder.Download
     ( cloneAndUpload
     , extractRemote
@@ -10,6 +11,7 @@ module SlackBuilder.Download
     , hostedSources
     , remoteFileExists
     , responseBodySource
+    , sinkFileAndHash
     , sinkHash
     , updateSlackBuildVersion
     , uploadCommand
@@ -66,7 +68,7 @@ import Conduit
     , (.|)
     , ZipSink(..)
     , await
-    , sourceFile
+    , sourceFile, MonadResource
     )
 import Data.Conduit.Tar (untar, FileInfo(..))
 import Crypto.Hash (Digest, MD5, hashInit, hashFinalize, hashUpdate)
@@ -244,9 +246,14 @@ download uri packagePath = runReq defaultHttpConfig go
             target = packagePath </> fromMaybe downloadFileName attachmentName
         digest <- runConduitRes
             $ responseBodySource response
-            .| getZipSink (ZipSink (sinkFile target) *> ZipSink sinkHash)
+            .| sinkFileAndHash target
         pure (targetFileName, digest)
 
+-- | Writes a file to the destination path and accumulates its MD5 checksum.
+sinkFileAndHash :: MonadResource m => FilePath -> ConduitT ByteString Void m (Digest MD5)
+sinkFileAndHash target = getZipSink
+    $ ZipSink (sinkFile target) *> ZipSink sinkHash
+
 -- | Downloads a compressed tar archive and extracts its contents on the fly to
 -- a directory.
 --

lib/SlackBuilder/Package.hs

@@ -2,6 +2,7 @@
    v. 2.0. If a copy of the MPL was not distributed with this file, You can
    obtain one at https://mozilla.org/MPL/2.0/. -}
 
+-- | Contains data describing packages and how they are should be updated,
 module SlackBuilder.Package
     ( DownloadPlaceholder(..)
     , Download(..)