1 files changed, 57 insertions, 0 deletions
diff --git a/pkg/v1/tarball/progress_test.go b/pkg/v1/tarball/progress_test.go
new file mode 100644
index 0000000..c722749
--- /dev/null
+++ b/pkg/v1/tarball/progress_test.go
@@ -0,0 +1,57 @@
+// Copyright 2018 Google LLC All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package tarball_test
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"os"
+
+	v1 "github.com/google/go-containerregistry/pkg/v1"
+	"github.com/google/go-containerregistry/pkg/v1/tarball"
+)
+
+func ExampleWithProgress() {
+	// buffered channel to make the example test easier
+	c := make(chan v1.Update, 200)
+	// Make a tempfile for tarball writes.
+	fp, err := os.CreateTemp("", "")
+	if err != nil {
+		fmt.Printf("error creating temp file: %v\n", err)
+		return
+	}
+	defer fp.Close()
+	defer os.Remove(fp.Name())
+
+	img, err := tarball.ImageFromPath("testdata/test_image_1.tar", nil)
+	go func() {
+		_ = tarball.WriteToFile(fp.Name(), nil, img, tarball.WithProgress(c))
+	}()
+	for update := range c {
+		switch {
+		case update.Error != nil && errors.Is(update.Error, io.EOF):
+			fmt.Fprintf(os.Stderr, "receive error message: %v\n", err)
+			fmt.Printf("%d/%d", update.Complete, update.Total)
+			// Output: 4096/4096
+			return
+		case update.Error != nil:
+			fmt.Printf("error writing tarball: %v\n", update.Error)
+			return
+		default:
+			fmt.Fprintf(os.Stderr, "receive update: %#v\n", update)
+		}
+	}
+}