extract pullDryRunSimulate from pullDryRun

pkg/compose/pull.go

@@ -53,7 +53,7 @@ type pullDryRunServiceResult struct {
 	Plan               string
 }
 
-type pullDrayRunView struct {
+type pullDryRunResults struct {
 	Services []pullDryRunServiceResult
 }
 
@@ -69,6 +69,23 @@ func (s *composeService) Pull(ctx context.Context, project *types.Project, opts
 	})
 }
 
+func (s *composeService) pullDryRun(ctx context.Context, project *types.Project, opts api.PullOptions) error {
+	results, err := s.pullDryRunSimulate(ctx, project, opts)
+	if err != nil {
+		return err
+	}
+	return formatter.Print(results, opts.Format, os.Stdout, func(w io.Writer) {
+		for _, service := range results.Services {
+			d := service.DistributionDigest
+			if d == "" {
+				// follow `docker images --digests` format
+				d = "<none>"
+			}
+			_, _ = fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", service.Name, service.Image, service.Plan, d)
+		}
+	}, "SERVICE", "IMAGE", "PLAN", "REMOTE DIGEST")
+}
+
 func getEncodedRegistryAuth(image string, info moby.Info, configFile driver.Auth) (string, error) {
 	ref, err := reference.ParseNormalizedNamed(image)
 	if err != nil {
@@ -204,13 +221,13 @@ func getPullPlan(service types.ServiceConfig, localDigests []string, dstrDigest
 	return
 }
 
-func (s *composeService) pullDryRun(ctx context.Context, project *types.Project, opts api.PullOptions) error {
+func (s *composeService) pullDryRunSimulate(ctx context.Context, project *types.Project, opts api.PullOptions) (*pullDryRunResults, error) {
 	// ignore errors
 	dstrDigests, _ := s.getDistributionImagesDigests(ctx, project)
 
 	localDigests, err := s.getLocalImagesDigests(ctx, project)
 	if err != nil {
-		return err
+		return nil, err
 	}
 
 	var results []pullDryRunServiceResult
@@ -232,20 +249,8 @@ func (s *composeService) pullDryRun(ctx context.Context, project *types.Project,
 		results = append(results, *result)
 	}
 
-	view := &pullDrayRunView{
-		Services: results,
-	}
+	return &pullDryRunResults{Services: results}, nil
 
-	return formatter.Print(view, opts.Format, os.Stdout, func(w io.Writer) {
-		for _, result := range results {
-			d := result.DistributionDigest
-			if d == "" {
-				// follow `docker images --digests` format
-				d = "<none>"
-			}
-			_, _ = fmt.Fprintf(w, "%s\t%s\t%s\t%s\n", result.Name, result.Image, result.Plan, d)
-		}
-	}, "SERVICE", "IMAGE", "PLAN", "REMOTE DIGEST")
 }
 
 func (s *composeService) pullRequiredImages(ctx context.Context, project *types.Project, images map[string]string, quietPull bool) error {