explicit Close() error handling

Signed-off-by: Santiago M. Mola <santi@mola.io>

PublicGitArchive/pga/cmd/cache.go

@@ -52,20 +52,26 @@ func copy(ctx context.Context, source, dest FileSystem,
 	if err != nil {
 		return fmt.Errorf("could not create %s: %v", dest.Abs(destName), err)
 	}
-	defer checkClose(dest.Abs(destName), wc, &err)
 
 	rc, err := source.Open(sourceName)
 	if err != nil {
+		_ = wc.Close()
 		return err
 	}
-	defer checkClose(source.Abs(sourceName), rc, &err)
 
 	if _, err = cancelableCopy(ctx, wc, rc); err != nil {
+		_ = rc.Close()
+		_ = wc.Close()
 		return fmt.Errorf("could not copy %s to %s: %v",
 			source.Abs(sourceName), dest.Abs(destName), err)
 	}
 
-	return err
+	if err := rc.Close(); err != nil {
+		_ = wc.Close()
+		return err
+	}
+
+	return wc.Close()
 }
 
 const copyBufferSize = 512 * 1024
@@ -143,9 +149,3 @@ func getIndex(ctx context.Context) (io.ReadCloser, error) {
 	}
 	return gzip.NewReader(f)
 }
-
-func checkClose(name string, c io.Closer, err *error) {
-	if cerr := c.Close(); cerr != nil && *err == nil {
-		*err = fmt.Errorf("could not close %s: %v", name, cerr)
-	}
-}

PublicGitArchive/pga/cmd/list.go

@@ -24,27 +24,30 @@ var listCmd = &cobra.Command{
 		if err != nil {
 			return fmt.Errorf("could not open index file: %v", err)
 		}
-		defer checkClose("index", f, &err)
 
 		index, err := pga.IndexFromCSV(f)
 		if err != nil {
+			_ = f.Close()
 			return err
 		}
 
 		filter, err := filterFromFlags(cmd.Flags())
 		if err != nil {
+			_ = f.Close()
 			return err
 		}
 
 		formatter, err := formatterFromFlags(cmd.Flags())
 		if err != nil {
+			_ = f.Close()
 			return err
 		}
 
 		index = pga.WithFilter(index, filter)
 		for {
 			select {
 			case <-ctx.Done():
+				_ = f.Close()
 				return fmt.Errorf("command canceled")
 			default:
 			}
@@ -53,6 +56,7 @@ var listCmd = &cobra.Command{
 			if err == io.EOF {
 				break
 			} else if err != nil {
+				_ = f.Close()
 				return err
 			}
 
@@ -62,7 +66,8 @@ var listCmd = &cobra.Command{
 				fmt.Print(s)
 			}
 		}
-		return err
+
+		return f.Close()
 	},
 }