Basic POSIX-compatible tar writer.

R=rsc
APPROVED=rsc
DELTA=456  (382 added, 66 deleted, 8 changed)
OCL=31246
CL=31372

1 files changed, 122 insertions, 0 deletions

diff --git a/src/pkg/archive/tar/writer_test.go b/src/pkg/archive/tar/writer_test.go
new file mode 100644
index 000000000..202530a0f
--- /dev/null
+++ b/src/pkg/archive/tar/writer_test.go
@@ -0,0 +1,122 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package tar
+
+import (
+	"archive/tar";
+	"bytes";
+	"fmt";
+	"io";
+	"os";
+	"reflect";
+	"strings";
+	"testing";
+)
+
+type writerTestEntry struct {
+	header *Header;
+	contents string;
+}
+
+type writerTest struct {
+	file string;  // filename of expected output
+	entries []*writerTestEntry;
+}
+
+var writerTests = []*writerTest{
+	&writerTest{
+		file: "testdata/writer.tar",
+		entries: []*writerTestEntry{
+			&writerTestEntry{
+				header: &Header{
+					Name: "small.txt",
+					Mode: 0640,
+					Uid: 73025,
+					Gid: 5000,
+					Size: 5,
+					Mtime: 1246508266,
+					Typeflag: '0',
+					Uname: "dsymonds",
+					Gname: "eng",
+				},
+				contents: `Kilts`,
+			},
+			&writerTestEntry{
+				header: &Header{
+					Name: "small2.txt",
+					Mode: 0640,
+					Uid: 73025,
+					Gid: 5000,
+					Size: 11,
+					Mtime: 1245217492,
+					Typeflag: '0',
+					Uname: "dsymonds",
+					Gname: "eng",
+				},
+				contents: "Google.com\n",
+			},
+		}
+	},
+}
+
+// Render byte array in a two-character hexadecimal string, spaced for easy visual inspection.
+func bytestr(b []byte) string {
+	s := fmt.Sprintf("(%d bytes)\n", len(b));
+	const rowLen = 32;
+	for i, ch := range b {
+		if i % rowLen == 0 {
+			// start of line: hex offset
+			s += fmt.Sprintf("%04x", i);
+		}
+		switch {
+		case '0' <= ch && ch <= '9', 'A' <= ch && ch <= 'Z', 'a' <= ch && ch <= 'z':
+			s += fmt.Sprintf("  %c", ch);
+		default:
+			s += fmt.Sprintf(" %02x", ch);
+		}
+		if (i + 1) % rowLen == 0 {
+			// end of line
+			s += "\n";
+		} else if (i + 1) % (rowLen / 2) == 0 {
+			// extra space
+			s += " ";
+		}
+	}
+	if s[len(s)-1] != '\n' {
+		s += "\n"
+	}
+	return s
+}
+
+func TestWriter(t *testing.T) {
+testLoop:
+	for i, test := range writerTests {
+		expected, err := io.ReadFile(test.file);
+		if err != nil {
+			t.Errorf("test %d: Unexpected error: %v", i, err);
+			continue
+		}
+
+		buf := new(bytes.Buffer);
+		tw := NewWriter(buf);
+		for j, entry := range test.entries {
+			if err := tw.WriteHeader(entry.header); err != nil {
+				t.Errorf("test %d, entry %d: Failed writing header: %v", i, j, err);
+				continue testLoop
+			}
+			if n, err := io.WriteString(tw, entry.contents); err != nil {
+				t.Errorf("test %d, entry %d: Failed writing contents: %v", i, j, err);
+				continue testLoop
+			}
+		}
+		tw.Close();
+
+		actual := buf.Data();
+		if !bytes.Equal(expected, actual) {
+			t.Errorf("test %d: Incorrect result:\n%v\nwant:\n%v",
+				 i, bytestr(actual), bytestr(expected));
+		}
+	}
+}