chore: refactor duplication

internal/docker/image.go

@@ -36,37 +36,8 @@ func (cli *Client) PullImage(
 		return nil, err
 	}
 
-	decoder := json.NewDecoder(respBody)
 	ch := make(chan PullPushImageMessage)
-
+	go processPullPushImageResp(ctx, respBody, ch)
-	go func() {
-		defer respBody.Close()
-		defer close(ch)
-
-		for {
-			var jm jsonmessage.JSONMessage
-			if err = decoder.Decode(&jm); err != nil {
-				if errors.Is(err, io.EOF) {
-					break
-				}
-				ch <- PullPushImageMessage{Err: fmt.Errorf("decode image pull message: %w", err)}
-				break
-			}
-
-			msg := PullPushImageMessage{Message: jm}
-			if jm.Error != nil {
-				msg.Err = errors.New(jm.Error.Message)
-			}
-
-			select {
-			case <-ctx.Done():
-				ch <- PullPushImageMessage{Err: ctx.Err()}
-				return
-			default:
-				ch <- msg
-			}
-		}
-	}()
 
 	return ch, nil
 }
@@ -87,21 +58,27 @@ func (cli *Client) PushImage(
 		return nil, err
 	}
 
-	decoder := json.NewDecoder(respBody)
 	ch := make(chan PullPushImageMessage)
+	go processPullPushImageResp(ctx, respBody, ch)
 
-	go func() {
+	return ch, nil
+}
+
+// processPullPushImageResp decodes JSON messages from the image pull/push response body and
+// sends them to the provided channel.
+func processPullPushImageResp(ctx context.Context, respBody io.ReadCloser, ch chan<- PullPushImageMessage) {
 	defer respBody.Close()
 	defer close(ch)
 
+	decoder := json.NewDecoder(respBody)
 	for {
 		var jm jsonmessage.JSONMessage
-			if err = decoder.Decode(&jm); err != nil {
+		if err := decoder.Decode(&jm); err != nil {
 			if errors.Is(err, io.EOF) {
-					break
+				return
 			}
-				ch <- PullPushImageMessage{Err: fmt.Errorf("decode image push message: %w", err)}
+			ch <- PullPushImageMessage{Err: fmt.Errorf("decode image pull/push message: %w", err)}
-				break
+			return
 		}
 
 		msg := PullPushImageMessage{Message: jm}
@@ -117,9 +94,6 @@ func (cli *Client) PushImage(
 			ch <- msg
 		}
 	}
-	}()
-
-	return ch, nil
 }
 
 // RetrieveLocalDockerRegistryAuth retrieves the authentication token for the specified image from the local Docker