// 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 tabwriter
import (
"bytes"
"fmt"
"io"
"testing"
)
type buffer struct {
a []byte
}
func (b *buffer) init(n int) { b.a = make([]byte, 0, n) }
func (b *buffer) clear() { b.a = b.a[0:0] }
func (b *buffer) Write(buf []byte) (written int, err error) {
n := len(b.a)
m := len(buf)
if n+m <= cap(b.a) {
b.a = b.a[0 : n+m]
for i := 0; i < m; i++ {
b.a[n+i] = buf[i]
}
} else {
panic("buffer.Write: buffer too small")
}
return len(buf), nil
}
func (b *buffer) String() string { return string(b.a) }
func write(t *testing.T, testname string, w *Writer, src string) {
t.Helper()
written, err := io.WriteString(w, src)
if err != nil {
t.Errorf("--- test: %s\n--- src:\n%q\n--- write error: %v\n", testname, src, err)
}
if written != len(src) {
t.Errorf("--- test: %s\n--- src:\n%q\n--- written = %d, len(src) = %d\n", testname, src, written, len(src))
}
}
func verify(t *testing.T, testname string, w *Writer, b *buffer, src, expected string) {
t.Helper()
err := w.Flush()
if err != nil {
t.Errorf("--- test: %s\n--- src:\n%q\n--- flush error: %v\n", testname, src, err)
}
res := b.String()
if res != expected {
t.Errorf("--- test: %s\n--- src:\n%q\n--- found:\n%q\n--- expected:\n%q\n", testname, src, res, expected)
}
}
func check(t *testing.T, testname string, minwidth, tabwidth, padding int, padchar byte, flags uint, src, expected string) {
t.Helper()
var b buffer
b.init(1000)
var w Writer
w.Init(&b, minwidth, tabwidth, padding, padchar, flags)
// write all at once
title := testname + " (written all at once)"
b.clear()
write(t, title, &w, src)
verify(t, title, &w, &b, src, expected)
// write byte-by-byte
title = testname + " (written byte-by-byte)"
b.clear()
for i := 0; i < len(src); i++ {
write(t, title, &w, src[i:i+1])
}
verify(t, title, &w, &b, src, expected)
// write using Fibonacci slice sizes
title = testname + " (written in fibonacci slices)"
b.clear()
for i, d := 0, 0; i < len(src); {
write(t, title, &w, src[i:i+d])
i, d = i+d, d+1
if i+d > len(src) {
d = len(src) - i
}
}
verify(t, title, &w, &b, src, expected)
}
var tests = []struct {
testname string
minwidth, tabwidth, padding int
padchar byte
flags uint
src, expected string
}{
{
"1a",
8, 0, 1, '.', 0,
"",
"",
},
{
"1a debug",
8, 0, 1, '.', Debug,
"",
"",
},
{
"1b esc stripped",
8, 0, 1, '.', StripEscape,
"\xff\xff",
"",
},
{
"1b esc",
8, 0, 1, '.', 0,
"\xff\xff",
"\xff\xff",
},
{
"1c esc stripped",
8, 0, 1, '.', StripEscape,
"\xff\t\xff",
"\t",
},
{
"1c esc",
8, 0, 1, '.', 0,
"\xff\t\xff",
"\xff\t\xff",
},
{
"1d esc stripped",
8, 0, 1, '.', StripEscape,
"\xff\"foo\t\n\tbar\"\xff",
"\"foo\t\n\tbar\"",
},
{
"1d esc",
8, 0, 1, '.', 0,
"\xff\"foo\t\n\tbar\"\xff",
"\xff\"foo\t\n\tbar\"\xff",
},
{
"1e esc stripped",
8, 0, 1, '.', StripEscape,
"abc\xff\tdef", // unterminated escape
"abc\tdef",
},
{
"1e esc",
8, 0, 1, '.', 0,
"abc\xff\tdef", // unterminated escape
"abc\xff\tdef",
},
{
"2",
8, 0, 1, '.', 0,
"\n\n\n",
"\n\n\n",
},
{
"3",
8, 0, 1, '.', 0,
"a\nb\nc",
"a\nb\nc",
},
{
"4a",
8, 0, 1, '.', 0,
"\t", // '\t' terminates an empty cell on last line - nothing to print
"",
},
{
"4b",
8, 0, 1, '.', AlignRight,
"\t", // '\t' terminates an empty cell on last line - nothing to print
"",
},
{
"5",
8, 0, 1, '.', 0,
"*\t*",
"*.......*",
},
{
"5b",
8, 0, 1, '.', 0,
"*\t*\n",
"*.......*\n",
},
{
"5c",
8, 0, 1, '.', 0,
"*\t*\t",
"*.......*",
},
{
"5c debug",
8, 0, 1, '.', Debug,
"*\t*\t",
"*.......|*",
},
{
"5d",
8, 0, 1, '.', AlignRight,
"*\t*\t",
".......**",
},
{
"6",
8, 0, 1, '.', 0,
"\t\n",
"........\n",
},
{
"7a",
8, 0, 1, '.', 0,
"a) foo",
"a) foo",
},
{
"7b",
8, 0, 1, ' ', 0,
"b) foo\tbar",
"b) foo bar",
},
{
"7c",
8, 0, 1, '.', 0,
"c) foo\tbar\t",
"c) foo..bar",
},
{
"7d",
8, 0, 1, '.', 0,
"d) foo\tbar\n",
"d) foo..bar\n",
},
{
"7e",
8, 0, 1, '.', 0,
"e) foo\tbar\t\n",
"e) foo..bar.....\n",
},
{
"7f",
8, 0, 1, '.', FilterHTML,
"f) f<o\tbar\t\n",
"f) f<o..bar.....\n",
},
{
"7g",
8, 0, 1, '.', FilterHTML,
"g) f<o\tbar\t non-terminated entity &",
"g) f<o..bar..... non-terminated entity &",
},
{
"7g debug",
8, 0, 1, '.', FilterHTML | Debug,
"g) f<o\tbar\t non-terminated entity &",
"g) f<o..|bar.....| non-terminated entity &",
},
{
"8",
8, 0, 1, '*', 0,
"Hello, world!\n",
"Hello, world!\n",
},
{
"9a",
1, 0, 0, '.', 0,
"1\t2\t3\t4\n" +
"11\t222\t3333\t44444\n",
"1.2..3...4\n" +
"11222333344444\n",
},
{
"9b",
1, 0, 0, '.', FilterHTML,
"1\t2\t3\t4\n" + // \f inside HTML is ignored
"11\t222\t3333\t44444\n",
"1.2..3...4\n" +
"11222333344444\n",
},
{
"9c",
1, 0, 0, '.', 0,
"1\t2\t3\t4\f" + // \f causes a newline and flush
"11\t222\t3333\t44444\n",
"1234\n" +
"11222333344444\n",
},
{
"9c debug",
1, 0, 0, '.', Debug,
"1\t2\t3\t4\f" + // \f causes a newline and flush
"11\t222\t3333\t44444\n",
"1|2|3|4\n" +
"---\n" +
"11|222|3333|44444\n",
},
{
"10a",
5, 0, 0, '.', 0,
"1\t2\t3\t4\n",
"1....2....3....4\n",
},
{
"10b",
5, 0, 0, '.', 0,
"1\t2\t3\t4\t\n",
"1....2....3....4....\n",
},
{
"11",
8, 0, 1, '.', 0,
"本\tb\tc\n" +
"aa\t\u672c\u672c\u672c\tcccc\tddddd\n" +
"aaa\tbbbb\n",
"本......b.......c\n" +
"aa......本本本..cccc....ddddd\n" +
"aaa.....bbbb\n",
},
{
"12a",
8, 0, 1, ' ', AlignRight,
"a\tè\tc\t\n" +
"aa\tèèè\tcccc\tddddd\t\n" +
"aaa\tèèèè\t\n",
" a è c\n" +
" aa èèè cccc ddddd\n" +
" aaa èèèè\n",
},
{
"12b",
2, 0, 0, ' ', 0,
"a\tb\tc\n" +
"aa\tbbb\tcccc\n" +
"aaa\tbbbb\n",
"a b c\n" +
"aa bbbcccc\n" +
"aaabbbb\n",
},
{
"12c",
8, 0, 1, '_', 0,
"a\tb\tc\n" +
"aa\tbbb\tcccc\n" +
"aaa\tbbbb\n",
"a_______b_______c\n" +
"aa______bbb_____cccc\n" +
"aaa_____bbbb\n",
},
{
"13a",
4, 0, 1, '-', 0,
"4444\t日本語\t22\t1\t333\n" +
"999999999\t22\n" +
"7\t22\n" +
"\t\t\t88888888\n" +
"\n" +
"666666\t666666\t666666\t4444\n" +
"1\t1\t999999999\t0000000000\n",
"4444------日本語-22--1---333\n" +
"999999999-22\n" +
"7---------22\n" +
"------------------88888888\n" +
"\n" +
"666666-666666-666666----4444\n" +
"1------1------999999999-0000000000\n",
},
{
"13b",
4, 0, 3, '.', 0,
"4444\t333\t22\t1\t333\n" +
"999999999\t22\n" +
"7\t22\n" +
"\t\t\t88888888\n" +
"\n" +
"666666\t666666\t666666\t4444\n" +
"1\t1\t999999999\t0000000000\n",
"4444........333...22...1...333\n" +
"999999999...22\n" +
"7...........22\n" +
"....................88888888\n" +
"\n" +
"666666...666666...666666......4444\n" +
"1........1........999999999...0000000000\n",
},
{
"13c",
8, 8, 1, '\t', FilterHTML,
"4444\t333\t22\t1\t333\n" +
"999999999\t22\n" +
"7\t22\n" +
"\t\t\t88888888\n" +
"\n" +
"666666\t666666\t666666\t4444\n" +
"1\t1\t999999999\t0000000000\n",
"4444\t\t333\t22\t1\t333\n" +
"999999999\t22\n" +
"7\t\t22\n" +
"\t\t\t\t88888888\n" +
"\n" +
"666666\t666666\t666666\t\t4444\n" +
"1\t1\t999999999\t0000000000\n",
},
{
"14",
1, 0, 2, ' ', AlignRight,
".0\t.3\t2.4\t-5.1\t\n" +
"23.0\t12345678.9\t2.4\t-989.4\t\n" +
"5.1\t12.0\t2.4\t-7.0\t\n" +
".0\t0.0\t332.0\t8908.0\t\n" +
".0\t-.3\t456.4\t22.1\t\n" +
".0\t1.2\t44.4\t-13.3\t\t",
" .0 .3 2.4 -5.1\n" +
" 23.0 12345678.9 2.4 -989.4\n" +
" 5.1 12.0 2.4 -7.0\n" +
" .0 0.0 332.0 8908.0\n" +
" .0 -.3 456.4 22.1\n" +
" .0 1.2 44.4 -13.3",
},
{
"14 debug",
1, 0, 2, ' ', AlignRight | Debug,
".0\t.3\t2.4\t-5.1\t\n" +
"23.0\t12345678.9\t2.4\t-989.4\t\n" +
"5.1\t12.0\t2.4\t-7.0\t\n" +
".0\t0.0\t332.0\t8908.0\t\n" +
".0\t-.3\t456.4\t22.1\t\n" +
".0\t1.2\t44.4\t-13.3\t\t",
" .0| .3| 2.4| -5.1|\n" +
" 23.0| 12345678.9| 2.4| -989.4|\n" +
" 5.1| 12.0| 2.4| -7.0|\n" +
" .0| 0.0| 332.0| 8908.0|\n" +
" .0| -.3| 456.4| 22.1|\n" +
" .0| 1.2| 44.4| -13.3|",
},
{
"15a",
4, 0, 0, '.', 0,
"a\t\tb",
"a.......b",
},
{
"15b",
4, 0, 0, '.', DiscardEmptyColumns,
"a\t\tb", // htabs - do not discard column
"a.......b",
},
{
"15c",
4, 0, 0, '.', DiscardEmptyColumns,
"a\v\vb",
"a...b",
},
{
"15d",
4, 0, 0, '.', AlignRight | DiscardEmptyColumns,
"a\v\vb",
"...ab",
},
{
"16a",
100, 100, 0, '\t', 0,
"a\tb\t\td\n" +
"a\tb\t\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
"a\tb\t\td\n" +
"a\tb\t\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
},
{
"16b",
100, 100, 0, '\t', DiscardEmptyColumns,
"a\vb\v\vd\n" +
"a\vb\v\vd\ve\n" +
"a\n" +
"a\vb\vc\vd\n" +
"a\vb\vc\vd\ve\n",
"a\tb\td\n" +
"a\tb\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
},
{
"16b debug",
100, 100, 0, '\t', DiscardEmptyColumns | Debug,
"a\vb\v\vd\n" +
"a\vb\v\vd\ve\n" +
"a\n" +
"a\vb\vc\vd\n" +
"a\vb\vc\vd\ve\n",
"a\t|b\t||d\n" +
"a\t|b\t||d\t|e\n" +
"a\n" +
"a\t|b\t|c\t|d\n" +
"a\t|b\t|c\t|d\t|e\n",
},
{
"16c",
100, 100, 0, '\t', DiscardEmptyColumns,
"a\tb\t\td\n" + // hard tabs - do not discard column
"a\tb\t\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
"a\tb\t\td\n" +
"a\tb\t\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
},
{
"16c debug",
100, 100, 0, '\t', DiscardEmptyColumns | Debug,
"a\tb\t\td\n" + // hard tabs - do not discard column
"a\tb\t\td\te\n" +
"a\n" +
"a\tb\tc\td\n" +
"a\tb\tc\td\te\n",
"a\t|b\t|\t|d\n" +
"a\t|b\t|\t|d\t|e\n" +
"a\n" +
"a\t|b\t|c\t|d\n" +
"a\t|b\t|c\t|d\t|e\n",
},
}
func Test(t *testing.T) {
for _, e := range tests {
check(t, e.testname, e.minwidth, e.tabwidth, e.padding, e.padchar, e.flags, e.src, e.expected)
}
}
type panicWriter struct{}
func (panicWriter) Write([]byte) (int, error) {
panic("cannot write")
}
func wantPanicString(t *testing.T, want string) {
t.Helper()
if e := recover(); e != nil {
got, ok := e.(string)
switch {
case !ok:
t.Errorf("got %v (%T), want panic string", e, e)
case got != want:
t.Errorf("wrong panic message: got %q, want %q", got, want)
}
}
}
func TestPanicDuringFlush(t *testing.T) {
defer wantPanicString(t, "tabwriter: panic during Flush")
var p panicWriter
w := new(Writer)
w.Init(p, 0, 0, 5, ' ', 0)
io.WriteString(w, "a")
w.Flush()
t.Errorf("failed to panic during Flush")
}
func TestPanicDuringWrite(t *testing.T) {
defer wantPanicString(t, "tabwriter: panic during Write")
var p panicWriter
w := new(Writer)
w.Init(p, 0, 0, 5, ' ', 0)
io.WriteString(w, "a\n\n") // the second \n triggers a call to w.Write and thus a panic
t.Errorf("failed to panic during Write")
}
func BenchmarkTable(b *testing.B) {
for _, w := range [...]int{1, 10, 100} {
// Build a line with w cells.
line := bytes.Repeat([]byte("a\t"), w)
line = append(line, '\n')
for _, h := range [...]int{10, 1000, 100000} {
b.Run(fmt.Sprintf("%dx%d", w, h), func(b *testing.B) {
b.Run("new", func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
// Write the line h times.
for j := 0; j < h; j++ {
w.Write(line)
}
w.Flush()
}
})
b.Run("reuse", func(b *testing.B) {
b.ReportAllocs()
w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
for i := 0; i < b.N; i++ {
// Write the line h times.
for j := 0; j < h; j++ {
w.Write(line)
}
w.Flush()
}
})
})
}
}
}
func BenchmarkPyramid(b *testing.B) {
for _, x := range [...]int{10, 100, 1000} {
// Build a line with x cells.
line := bytes.Repeat([]byte("a\t"), x)
b.Run(fmt.Sprintf("%d", x), func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
// Write increasing prefixes of that line.
for j := 0; j < x; j++ {
w.Write(line[:j*2])
w.Write([]byte{'\n'})
}
w.Flush()
}
})
}
}
func BenchmarkRagged(b *testing.B) {
var lines [8][]byte
for i, w := range [8]int{6, 2, 9, 5, 5, 7, 3, 8} {
// Build a line with w cells.
lines[i] = bytes.Repeat([]byte("a\t"), w)
}
for _, h := range [...]int{10, 100, 1000} {
b.Run(fmt.Sprintf("%d", h), func(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
// Write the lines in turn h times.
for j := 0; j < h; j++ {
w.Write(lines[j%len(lines)])
w.Write([]byte{'\n'})
}
w.Flush()
}
})
}
}
const codeSnippet = `
some command
foo # aligned
barbaz # comments
but
mostly
single
cell
lines
`
func BenchmarkCode(b *testing.B) {
b.ReportAllocs()
for i := 0; i < b.N; i++ {
w := NewWriter(io.Discard, 4, 4, 1, ' ', 0) // no particular reason for these settings
// The code is small, so it's reasonable for the tabwriter user
// to write it all at once, or buffer the writes.
w.Write([]byte(codeSnippet))
w.Flush()
}
}