dep: Update containers/image to 1d7e25b91705e4d1cddb5396baf112caeb1119f3

Signed-off-by: Andrew Pilloud <andrewpilloud@igneoussystems.com>

vendor/github.com/containers/image/pkg/compression/compression_test.go

@@ -0,0 +1,86 @@
+package compression
+
+import (
+	"bytes"
+	"io"
+	"io/ioutil"
+	"os"
+	"testing"
+
+	"github.com/pkg/errors"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestDetectCompression(t *testing.T) {
+	cases := []struct {
+		filename      string
+		unimplemented bool
+	}{
+		{"fixtures/Hello.uncompressed", false},
+		{"fixtures/Hello.gz", false},
+		{"fixtures/Hello.bz2", false},
+		{"fixtures/Hello.xz", true},
+	}
+
+	// The original stream is preserved.
+	for _, c := range cases {
+		originalContents, err := ioutil.ReadFile(c.filename)
+		require.NoError(t, err, c.filename)
+
+		stream, err := os.Open(c.filename)
+		require.NoError(t, err, c.filename)
+		defer stream.Close()
+
+		_, updatedStream, err := DetectCompression(stream)
+		require.NoError(t, err, c.filename)
+
+		updatedContents, err := ioutil.ReadAll(updatedStream)
+		require.NoError(t, err, c.filename)
+		assert.Equal(t, originalContents, updatedContents, c.filename)
+	}
+
+	// The correct decompressor is chosen, and the result is as expected.
+	for _, c := range cases {
+		stream, err := os.Open(c.filename)
+		require.NoError(t, err, c.filename)
+		defer stream.Close()
+
+		decompressor, updatedStream, err := DetectCompression(stream)
+		require.NoError(t, err, c.filename)
+
+		var uncompressedStream io.Reader
+		switch {
+		case decompressor == nil:
+			uncompressedStream = updatedStream
+		case c.unimplemented:
+			_, err := decompressor(updatedStream)
+			assert.Error(t, err)
+			continue
+		default:
+			s, err := decompressor(updatedStream)
+			require.NoError(t, err)
+			uncompressedStream = s
+		}
+
+		uncompressedContents, err := ioutil.ReadAll(uncompressedStream)
+		require.NoError(t, err, c.filename)
+		assert.Equal(t, []byte("Hello"), uncompressedContents, c.filename)
+	}
+
+	// Empty input is handled reasonably.
+	decompressor, updatedStream, err := DetectCompression(bytes.NewReader([]byte{}))
+	require.NoError(t, err)
+	assert.Nil(t, decompressor)
+	updatedContents, err := ioutil.ReadAll(updatedStream)
+	require.NoError(t, err)
+	assert.Equal(t, []byte{}, updatedContents)
+
+	// Error reading input
+	reader, writer := io.Pipe()
+	defer reader.Close()
+	writer.CloseWithError(errors.New("Expected error reading input in DetectCompression"))
+	_, _, err = DetectCompression(reader)
+	assert.Error(t, err)
+}