Ensure file handles are always closed (#122)

* [core] Ensure files are closed even when interrupted

* [changelog] updated

CHANGELOG.org

@@ -12,6 +12,7 @@ The format is based on [[https://keepachangelog.com/en/1.0.0/][Keep a Changelog]
 
    - Log copy and delete operations (#119)
    - Log errors with red label (#119)
+   - Ensure file handles are always closed (#122)
 
 ** Changed
 

core/src/main/scala/net/kemitix/thorp/core/MD5HashGenerator.scala

@@ -5,7 +5,7 @@ import java.nio.file.Path
 import java.security.MessageDigest
 
 import net.kemitix.thorp.domain.MD5Hash
-import zio.Task
+import zio.{Task, UIO, ZManaged}
 
 import scala.collection.immutable.NumericRange
 
@@ -47,22 +47,22 @@ object MD5HashGenerator {
       offset: Long,
       endOffset: Long
   ) =
-    for {
-      fis    <- openFile(file, offset)
-      digest <- digestFile(fis, offset, endOffset)
-      _      <- closeFile(fis)
-    } yield digest
+    openFile(file, offset)
+      .use(digestFile(_, offset, endOffset))
 
   private def openFile(
       file: File,
       offset: Long
-  ) = Task {
+  ) =
+    ZManaged.make {
+      Task {
         val stream = new FileInputStream(file)
         stream skip offset
         stream
       }
+    }(closeFile)
 
-  private def closeFile(fis: FileInputStream) = Task(fis.close())
+  private def closeFile(fis: FileInputStream) = UIO(fis.close())
 
   private def digestFile(
       fis: FileInputStream,