archive/tar: compact slices in tests

Took this opportunity to also embed tables in the functions
that they are actually used in and other stylistic cleanups.

There was no logical changes to the tests.

Change-Id: Ifa724060532175f6f4407d6cedc841891efd8f7b
Reviewed-on: https://go-review.googlesource.com/31436
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/archive/tar/tar_test.go

@@ -135,9 +135,8 @@ type headerRoundTripTest struct {
 }
 
 func TestHeaderRoundTrip(t *testing.T) {
-	golden := []headerRoundTripTest{
+	vectors := []headerRoundTripTest{{
 		// regular file.
-		{
 		h: &Header{
 			Name:     "test.txt",
 			Mode:     0644 | c_ISREG,
@@ -146,9 +145,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeReg,
 		},
 		fm: 0644,
-		},
+	}, {
 		// symbolic link.
-		{
 		h: &Header{
 			Name:     "link.txt",
 			Mode:     0777 | c_ISLNK,
@@ -157,9 +155,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeSymlink,
 		},
 		fm: 0777 | os.ModeSymlink,
-		},
+	}, {
 		// character device node.
-		{
 		h: &Header{
 			Name:     "dev/null",
 			Mode:     0666 | c_ISCHR,
@@ -168,9 +165,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeChar,
 		},
 		fm: 0666 | os.ModeDevice | os.ModeCharDevice,
-		},
+	}, {
 		// block device node.
-		{
 		h: &Header{
 			Name:     "dev/sda",
 			Mode:     0660 | c_ISBLK,
@@ -179,9 +175,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeBlock,
 		},
 		fm: 0660 | os.ModeDevice,
-		},
+	}, {
 		// directory.
-		{
 		h: &Header{
 			Name:     "dir/",
 			Mode:     0755 | c_ISDIR,
@@ -190,9 +185,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeDir,
 		},
 		fm: 0755 | os.ModeDir,
-		},
+	}, {
 		// fifo node.
-		{
 		h: &Header{
 			Name:     "dev/initctl",
 			Mode:     0600 | c_ISFIFO,
@@ -201,9 +195,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeFifo,
 		},
 		fm: 0600 | os.ModeNamedPipe,
-		},
+	}, {
 		// setuid.
-		{
 		h: &Header{
 			Name:     "bin/su",
 			Mode:     0755 | c_ISREG | c_ISUID,
@@ -212,9 +205,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeReg,
 		},
 		fm: 0755 | os.ModeSetuid,
-		},
+	}, {
 		// setguid.
-		{
 		h: &Header{
 			Name:     "group.txt",
 			Mode:     0750 | c_ISREG | c_ISGID,
@@ -223,9 +215,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeReg,
 		},
 		fm: 0750 | os.ModeSetgid,
-		},
+	}, {
 		// sticky.
-		{
 		h: &Header{
 			Name:     "sticky.txt",
 			Mode:     0600 | c_ISREG | c_ISVTX,
@@ -234,9 +225,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeReg,
 		},
 		fm: 0600 | os.ModeSticky,
-		},
+	}, {
 		// hard link.
-		{
 		h: &Header{
 			Name:     "hard.txt",
 			Mode:     0644 | c_ISREG,
@@ -246,9 +236,8 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeLink,
 		},
 		fm: 0644,
-		},
+	}, {
 		// More information.
-		{
 		h: &Header{
 			Name:     "info.txt",
 			Mode:     0600 | c_ISREG,
@@ -261,64 +250,63 @@ func TestHeaderRoundTrip(t *testing.T) {
 			Typeflag: TypeReg,
 		},
 		fm: 0600,
-		},
-	}
+	}}
 
-	for i, g := range golden {
-		fi := g.h.FileInfo()
+	for i, v := range vectors {
+		fi := v.h.FileInfo()
 		h2, err := FileInfoHeader(fi, "")
 		if err != nil {
 			t.Error(err)
 			continue
 		}
 		if strings.Contains(fi.Name(), "/") {
-			t.Errorf("FileInfo of %q contains slash: %q", g.h.Name, fi.Name())
+			t.Errorf("FileInfo of %q contains slash: %q", v.h.Name, fi.Name())
 		}
-		name := path.Base(g.h.Name)
+		name := path.Base(v.h.Name)
 		if fi.IsDir() {
 			name += "/"
 		}
 		if got, want := h2.Name, name; got != want {
 			t.Errorf("i=%d: Name: got %v, want %v", i, got, want)
 		}
-		if got, want := h2.Size, g.h.Size; got != want {
+		if got, want := h2.Size, v.h.Size; got != want {
 			t.Errorf("i=%d: Size: got %v, want %v", i, got, want)
 		}
-		if got, want := h2.Uid, g.h.Uid; got != want {
+		if got, want := h2.Uid, v.h.Uid; got != want {
 			t.Errorf("i=%d: Uid: got %d, want %d", i, got, want)
 		}
-		if got, want := h2.Gid, g.h.Gid; got != want {
+		if got, want := h2.Gid, v.h.Gid; got != want {
 			t.Errorf("i=%d: Gid: got %d, want %d", i, got, want)
 		}
-		if got, want := h2.Uname, g.h.Uname; got != want {
+		if got, want := h2.Uname, v.h.Uname; got != want {
 			t.Errorf("i=%d: Uname: got %q, want %q", i, got, want)
 		}
-		if got, want := h2.Gname, g.h.Gname; got != want {
+		if got, want := h2.Gname, v.h.Gname; got != want {
 			t.Errorf("i=%d: Gname: got %q, want %q", i, got, want)
 		}
-		if got, want := h2.Linkname, g.h.Linkname; got != want {
+		if got, want := h2.Linkname, v.h.Linkname; got != want {
 			t.Errorf("i=%d: Linkname: got %v, want %v", i, got, want)
 		}
-		if got, want := h2.Typeflag, g.h.Typeflag; got != want {
-			t.Logf("%#v %#v", g.h, fi.Sys())
+		if got, want := h2.Typeflag, v.h.Typeflag; got != want {
+			t.Logf("%#v %#v", v.h, fi.Sys())
 			t.Errorf("i=%d: Typeflag: got %q, want %q", i, got, want)
 		}
-		if got, want := h2.Mode, g.h.Mode; got != want {
+		if got, want := h2.Mode, v.h.Mode; got != want {
 			t.Errorf("i=%d: Mode: got %o, want %o", i, got, want)
 		}
-		if got, want := fi.Mode(), g.fm; got != want {
+		if got, want := fi.Mode(), v.fm; got != want {
 			t.Errorf("i=%d: fi.Mode: got %o, want %o", i, got, want)
 		}
-		if got, want := h2.AccessTime, g.h.AccessTime; got != want {
+		if got, want := h2.AccessTime, v.h.AccessTime; got != want {
 			t.Errorf("i=%d: AccessTime: got %v, want %v", i, got, want)
 		}
-		if got, want := h2.ChangeTime, g.h.ChangeTime; got != want {
+		if got, want := h2.ChangeTime, v.h.ChangeTime; got != want {
 			t.Errorf("i=%d: ChangeTime: got %v, want %v", i, got, want)
 		}
-		if got, want := h2.ModTime, g.h.ModTime; got != want {
+		if got, want := h2.ModTime, v.h.ModTime; got != want {
 			t.Errorf("i=%d: ModTime: got %v, want %v", i, got, want)
 		}
-		if sysh, ok := fi.Sys().(*Header); !ok || sysh != g.h {
+		if sysh, ok := fi.Sys().(*Header); !ok || sysh != v.h {
 			t.Errorf("i=%d: Sys didn't return original *Header", i)
 		}
 	}

src/archive/tar/writer_test.go

@@ -18,25 +18,60 @@ import (
 	"time"
 )
 
-type writerTestEntry struct {
-	header   *Header
-	contents string
+// Render byte array in a two-character hexadecimal string, spaced for easy visual inspection.
+func bytestr(offset int, b []byte) string {
+	const rowLen = 32
+	s := fmt.Sprintf("%04x ", offset)
+	for _, ch := range b {
+		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)
+		}
+	}
+	return s
 }
 
-type writerTest struct {
-	file    string // filename of expected output
-	entries []*writerTestEntry
+// Render a pseudo-diff between two blocks of bytes.
+func bytediff(a []byte, b []byte) string {
+	const rowLen = 32
+	s := fmt.Sprintf("(%d bytes vs. %d bytes)\n", len(a), len(b))
+	for offset := 0; len(a)+len(b) > 0; offset += rowLen {
+		na, nb := rowLen, rowLen
+		if na > len(a) {
+			na = len(a)
+		}
+		if nb > len(b) {
+			nb = len(b)
+		}
+		sa := bytestr(offset, a[0:na])
+		sb := bytestr(offset, b[0:nb])
+		if sa != sb {
+			s += fmt.Sprintf("-%v\n+%v\n", sa, sb)
+		}
+		a = a[na:]
+		b = b[nb:]
+	}
+	return s
 }
 
-var writerTests = []*writerTest{
+func TestWriter(t *testing.T) {
+	type entry struct {
+		header   *Header
+		contents string
+	}
+
+	vectors := []struct {
+		file    string // filename of expected output
+		entries []*entry
+	}{{
 		// The writer test file was produced with this command:
 		// tar (GNU tar) 1.26
 		//   ln -s small.txt link.txt
 		//   tar -b 1 --format=ustar -c -f writer.tar small.txt small2.txt link.txt
-	{
 		file: "testdata/writer.tar",
-		entries: []*writerTestEntry{
-			{
+		entries: []*entry{{
 			header: &Header{
 				Name:     "small.txt",
 				Mode:     0640,
@@ -49,8 +84,7 @@ var writerTests = []*writerTest{
 				Gname:    "eng",
 			},
 			contents: "Kilts",
-			},
-			{
+		}, {
 			header: &Header{
 				Name:     "small2.txt",
 				Mode:     0640,
@@ -63,8 +97,7 @@ var writerTests = []*writerTest{
 				Gname:    "eng",
 			},
 			contents: "Google.com\n",
-			},
-			{
+		}, {
 			header: &Header{
 				Name:     "link.txt",
 				Mode:     0777,
@@ -78,16 +111,13 @@ var writerTests = []*writerTest{
 				Gname:    "strings",
 			},
 			// no contents
-			},
-		},
-	},
+		}},
+	}, {
 		// The truncated test file was produced using these commands:
 		//   dd if=/dev/zero bs=1048576 count=16384 > /tmp/16gig.txt
 		//   tar -b 1 -c -f- /tmp/16gig.txt | dd bs=512 count=8 > writer-big.tar
-	{
 		file: "testdata/writer-big.tar",
-		entries: []*writerTestEntry{
-			{
+		entries: []*entry{{
 			header: &Header{
 				Name:     "tmp/16gig.txt",
 				Mode:     0640,
@@ -101,16 +131,13 @@ var writerTests = []*writerTest{
 			},
 			// fake contents
 			contents: strings.Repeat("\x00", 4<<10),
-			},
-		},
-	},
+		}},
+	}, {
 		// The truncated test file was produced using these commands:
 		//   dd if=/dev/zero bs=1048576 count=16384 > (longname/)*15 /16gig.txt
 		//   tar -b 1 -c -f- (longname/)*15 /16gig.txt | dd bs=512 count=8 > writer-big-long.tar
-	{
 		file: "testdata/writer-big-long.tar",
-		entries: []*writerTestEntry{
-			{
+		entries: []*entry{{
 			header: &Header{
 				Name:     strings.Repeat("longname/", 15) + "16gig.txt",
 				Mode:     0644,
@@ -124,15 +151,12 @@ var writerTests = []*writerTest{
 			},
 			// fake contents
 			contents: strings.Repeat("\x00", 4<<10),
-			},
-		},
-	},
+		}},
+	}, {
 		// This file was produced using gnu tar 1.17
 		// gnutar  -b 4 --format=ustar (longname/)*15 + file.txt
-	{
 		file: "testdata/ustar.tar",
-		entries: []*writerTestEntry{
-			{
+		entries: []*entry{{
 			header: &Header{
 				Name:     strings.Repeat("longname/", 15) + "file.txt",
 				Mode:     0644,
@@ -145,17 +169,14 @@ var writerTests = []*writerTest{
 				Gname:    "staff",
 			},
 			contents: "hello\n",
-			},
-		},
-	},
+		}},
+	}, {
 		// This file was produced using gnu tar 1.26
 		// echo "Slartibartfast" > file.txt
 		// ln file.txt hard.txt
 		// tar -b 1 --format=ustar -c -f hardlink.tar file.txt hard.txt
-	{
 		file: "testdata/hardlink.tar",
-		entries: []*writerTestEntry{
-			{
+		entries: []*entry{{
 			header: &Header{
 				Name:     "file.txt",
 				Mode:     0644,
@@ -168,8 +189,7 @@ var writerTests = []*writerTest{
 				Gname:    "users",
 			},
 			contents: "Slartibartfast\n",
-			},
-			{
+		}, {
 			header: &Header{
 				Name:     "hard.txt",
 				Mode:     0644,
@@ -183,53 +203,12 @@ var writerTests = []*writerTest{
 				Gname:    "users",
 			},
 			// no contents
-			},
-		},
-	},
-}
-
-// Render byte array in a two-character hexadecimal string, spaced for easy visual inspection.
-func bytestr(offset int, b []byte) string {
-	const rowLen = 32
-	s := fmt.Sprintf("%04x ", offset)
-	for _, ch := range b {
-		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)
-		}
-	}
-	return s
-}
+		}},
+	}}
 
-// Render a pseudo-diff between two blocks of bytes.
-func bytediff(a []byte, b []byte) string {
-	const rowLen = 32
-	s := fmt.Sprintf("(%d bytes vs. %d bytes)\n", len(a), len(b))
-	for offset := 0; len(a)+len(b) > 0; offset += rowLen {
-		na, nb := rowLen, rowLen
-		if na > len(a) {
-			na = len(a)
-		}
-		if nb > len(b) {
-			nb = len(b)
-		}
-		sa := bytestr(offset, a[0:na])
-		sb := bytestr(offset, b[0:nb])
-		if sa != sb {
-			s += fmt.Sprintf("-%v\n+%v\n", sa, sb)
-		}
-		a = a[na:]
-		b = b[nb:]
-	}
-	return s
-}
-
-func TestWriter(t *testing.T) {
 testLoop:
-	for i, test := range writerTests {
-		expected, err := ioutil.ReadFile(test.file)
+	for i, v := range vectors {
+		expected, err := ioutil.ReadFile(v.file)
 		if err != nil {
 			t.Errorf("test %d: Unexpected error: %v", i, err)
 			continue
@@ -238,7 +217,7 @@ testLoop:
 		buf := new(bytes.Buffer)
 		tw := NewWriter(iotest.TruncateWriter(buf, 4<<10)) // only catch the first 4 KB
 		big := false
-		for j, entry := range test.entries {
+		for j, entry := range v.entries {
 			big = big || entry.header.Size > 1<<10
 			if err := tw.WriteHeader(entry.header); err != nil {
 				t.Errorf("test %d, entry %d: Failed writing header: %v", i, j, err)
@@ -575,9 +554,9 @@ func TestWriteAfterClose(t *testing.T) {
 }
 
 func TestSplitUSTARPath(t *testing.T) {
-	var sr = strings.Repeat
+	sr := strings.Repeat
 
-	var vectors = []struct {
+	vectors := []struct {
 		input  string // Input path
 		prefix string // Expected output prefix
 		suffix string // Expected output suffix