Repository navigation
Expand file tree
/
Copy pathjs.go
More file actions
87 lines (79 loc) · 2.82 KB
/
Copy pathjs.go
File metadata and controls
87 lines (79 loc) · 2.82 KB
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
// Package js minifies ECMAScript5.1 following the specifications at http://www.ecma-international.org/ecma-262/5.1/.
package js // import "github.com/tdewolff/minify/js"
import (
"io"
"github.com/tdewolff/minify"
"github.com/tdewolff/parse/js"
)
var (
spaceBytes = []byte(" ")
newlineBytes = []byte("\n")
semicolonBytes = []byte(";")
)
////////////////////////////////////////////////////////////////
// Minifier is a JS minifier.
type Minifier struct{}
// Minify minifies JS data, it reads from r and writes to w.
func Minify(m *minify.M, w io.Writer, r io.Reader, params map[string]string) error {
return (&Minifier{}).Minify(m, w, r, params)
}
// Minify minifies JS data, it reads from r and writes to w.
func (o *Minifier) Minify(_ *minify.M, w io.Writer, r io.Reader, _ map[string]string) error {
prev := js.LineTerminatorToken
prevLast := byte(' ')
lineTerminatorQueued := false
whitespaceQueued := false
semicolonQueued := false
l := js.NewLexer(r)
for {
tt, data := l.Next()
if tt == js.ErrorToken {
if l.Err() != io.EOF {
return l.Err()
}
return nil
} else if tt == js.LineTerminatorToken {
lineTerminatorQueued = true
} else if tt == js.WhitespaceToken {
whitespaceQueued = true
} else if tt != js.CommentToken {
first := data[0]
if tt == js.PunctuatorToken && first == ';' {
if semicolonQueued {
// when two semicolons follow, print them (such as in `for (var i = 0;;)`)
if _, err := w.Write(data); err != nil {
return err
}
}
semicolonQueued = true
} else {
if semicolonQueued && (tt != js.PunctuatorToken || first != '}') {
if _, err := w.Write(semicolonBytes); err != nil {
return err
}
}
if (prev == js.IdentifierToken || prev == js.NumericToken || prev == js.PunctuatorToken || prev == js.StringToken || prev == js.RegexpToken) && (tt == js.IdentifierToken || tt == js.NumericToken || tt == js.PunctuatorToken || tt == js.RegexpToken) {
if lineTerminatorQueued && (prev != js.PunctuatorToken || prevLast == '}' || prevLast == ']' || prevLast == ')' || prevLast == '+' || prevLast == '-' || prevLast == '"' || prevLast == '\'') && (tt != js.PunctuatorToken || first == '{' || first == '[' || first == '(' || first == '+' || first == '-') {
if _, err := w.Write(newlineBytes); err != nil {
return err
}
} else if whitespaceQueued && (prev != js.StringToken && prev != js.PunctuatorToken && tt != js.PunctuatorToken || (prevLast == '+' || prevLast == '-') && first == prevLast) {
if _, err := w.Write(spaceBytes); err != nil {
return err
}
}
}
if _, err := w.Write(data); err != nil {
return err
}
lineTerminatorQueued = false
whitespaceQueued = false
semicolonQueued = false
}
prev = tt
prevLast = data[len(data)-1]
}
l.Free(len(data))
}
return nil
}