1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
|
// 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 printer
import (
"bytes"
"flag"
"io/ioutil"
"go/ast"
"go/parser"
"go/token"
"path/filepath"
"testing"
)
const (
dataDir = "testdata"
tabwidth = 8
)
var update = flag.Bool("update", false, "update golden files")
var fset = token.NewFileSet()
func lineString(text []byte, i int) string {
i0 := i
for i < len(text) && text[i] != '\n' {
i++
}
return string(text[i0:i])
}
type checkMode uint
const (
export checkMode = 1 << iota
rawFormat
)
func check(t *testing.T, source, golden string, mode checkMode) {
// parse source
prog, err := parser.ParseFile(fset, source, nil, parser.ParseComments)
if err != nil {
t.Error(err)
return
}
// filter exports if necessary
if mode&export != 0 {
ast.FileExports(prog) // ignore result
prog.Comments = nil // don't print comments that are not in AST
}
// determine printer configuration
cfg := Config{Tabwidth: tabwidth}
if mode&rawFormat != 0 {
cfg.Mode |= RawFormat
}
// format source
var buf bytes.Buffer
if _, err := cfg.Fprint(&buf, fset, prog); err != nil {
t.Error(err)
}
res := buf.Bytes()
// update golden files if necessary
if *update {
if err := ioutil.WriteFile(golden, res, 0644); err != nil {
t.Error(err)
}
return
}
// get golden
gld, err := ioutil.ReadFile(golden)
if err != nil {
t.Error(err)
return
}
// compare lengths
if len(res) != len(gld) {
t.Errorf("len = %d, expected %d (= len(%s))", len(res), len(gld), golden)
}
// compare contents
for i, line, offs := 0, 1, 0; i < len(res) && i < len(gld); i++ {
ch := res[i]
if ch != gld[i] {
t.Errorf("%s:%d:%d: %s", source, line, i-offs+1, lineString(res, offs))
t.Errorf("%s:%d:%d: %s", golden, line, i-offs+1, lineString(gld, offs))
t.Error()
return
}
if ch == '\n' {
line++
offs = i + 1
}
}
}
type entry struct {
source, golden string
mode checkMode
}
// Use gotest -update to create/update the respective golden files.
var data = []entry{
{"empty.input", "empty.golden", 0},
{"comments.input", "comments.golden", 0},
{"comments.input", "comments.x", export},
{"linebreaks.input", "linebreaks.golden", 0},
{"expressions.input", "expressions.golden", 0},
{"expressions.input", "expressions.raw", rawFormat},
{"declarations.input", "declarations.golden", 0},
{"statements.input", "statements.golden", 0},
}
func TestFiles(t *testing.T) {
for _, e := range data {
source := filepath.Join(dataDir, e.source)
golden := filepath.Join(dataDir, e.golden)
check(t, source, golden, e.mode)
// TODO(gri) check that golden is idempotent
//check(t, golden, golden, e.mode);
}
}
// TestLineComments, using a simple test case, checks that consequtive line
// comments are properly terminated with a newline even if the AST position
// information is incorrect.
//
func TestLineComments(t *testing.T) {
const src = `// comment 1
// comment 2
// comment 3
package main
`
fset := token.NewFileSet()
ast1, err1 := parser.ParseFile(fset, "", src, parser.ParseComments)
if err1 != nil {
panic(err1)
}
var buf bytes.Buffer
fset = token.NewFileSet() // use the wrong file set
Fprint(&buf, fset, ast1)
nlines := 0
for _, ch := range buf.Bytes() {
if ch == '\n' {
nlines++
}
}
const expected = 3
if nlines < expected {
t.Errorf("got %d, expected %d\n", nlines, expected)
}
}
|
