File size: 6,935 Bytes
1e92f2d
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
use std::{
    borrow::Cow,
    fmt::{Display, Write},
};

use once_cell::sync::Lazy;
use regex::{Captures, Regex, Replacer};

pub fn mangle(content: &str) -> String {
    let mut r = "__TURBOPACK__".to_string();
    let mut hex_mode = false;
    for c in content.chars() {
        if matches!(c, '0'..='9' | 'A'..='Z' | 'a'..='z' | ' ') {
            if hex_mode {
                r.push('$');
                hex_mode = false;
            }
            if c == ' ' {
                r += "__";
            } else {
                r.push(c);
            }
        } else if c == '_' && (!r.ends_with('_') || hex_mode) {
            if hex_mode {
                r.push('$');
                hex_mode = false;
            }
            r += "_";
        } else if c == '$' && !hex_mode {
            r += "$$";
        } else if matches!(c, '\0'..='\u{ff}') {
            if !hex_mode {
                r.push('$');
                hex_mode = true;
            }
            write!(r, "{0:2x}", c as u8).unwrap();
        } else {
            if !hex_mode {
                r.push('$');
            }
            write!(r, "_{:x}$", c as u32).unwrap();
            hex_mode = false;
        }
    }
    if hex_mode {
        r.push('$');
    }
    r += "__";
    r
}

/// Decodes a magic identifier into a string.
pub fn unmangle(identifier: &str) -> String {
    static DECODE_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"^__TURBOPACK__([a-zA-Z0-9_$]+)__$").unwrap());

    let Some(captures) = DECODE_REGEX.captures(identifier) else {
        return identifier.to_string();
    };

    let content = captures.get(1).unwrap().as_str();

    enum Mode {
        Text,
        Underscore,
        Hex,
        LongHex,
    }
    let mut mode = Mode::Text;
    let mut output = String::new();
    let mut buffer = String::with_capacity(2);
    for char in content.chars() {
        match mode {
            Mode::Text => match char {
                '_' => mode = Mode::Underscore,
                '$' => mode = Mode::Hex,
                c => output.push(c),
            },
            Mode::Underscore => match char {
                '_' => {
                    output.push(' ');
                    mode = Mode::Text;
                }
                '$' => {
                    output.push('_');
                    mode = Mode::Hex;
                }
                c => {
                    output.push('_');
                    output.push(c);
                    mode = Mode::Text;
                }
            },
            Mode::Hex => {
                if buffer.len() == 2 {
                    if let Ok(byte) = u8::from_str_radix(&buffer, 16) {
                        output.push(byte as char);
                    }
                    buffer.clear();
                }
                match char {
                    '_' => {
                        debug_assert!(buffer.is_empty());
                        mode = Mode::LongHex;
                    }
                    '$' => {
                        debug_assert!(buffer.is_empty());
                        mode = Mode::Text;
                    }
                    c => {
                        buffer.push(c);
                    }
                }
            }
            Mode::LongHex => {
                debug_assert!(char != '_');
                match char {
                    '$' => {
                        if let Ok(code) = u32::from_str_radix(&buffer, 16) {
                            output.push(std::char::from_u32(code).unwrap());
                        }
                        buffer.clear();
                        mode = Mode::Text;
                    }
                    c => {
                        buffer.push(c);
                    }
                }
            }
        }
    }
    debug_assert!(matches!(mode, Mode::Text));
    output
}

/// Decode all magic identifiers in a string.
pub fn unmangle_identifiers<T: Display>(text: &str, magic: impl Fn(String) -> T) -> Cow<'_, str> {
    static IDENTIFIER_REGEX: Lazy<Regex> =
        Lazy::new(|| Regex::new(r"__TURBOPACK__[a-zA-Z0-9_$]+__").unwrap());

    struct Rep<T: Fn(String) -> O, O: Display>(T);

    impl<T: Fn(String) -> O, O: Display> Replacer for Rep<T, O> {
        fn replace_append(&mut self, caps: &Captures<'_>, dst: &mut String) {
            write!(dst, "{}", self.0(unmangle(caps.get(0).unwrap().as_str()))).unwrap();
        }
    }

    IDENTIFIER_REGEX.replace_all(text, Rep(magic))
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_encode() {
        assert_eq!(mangle("Hello World"), "__TURBOPACK__Hello__World__");
        assert_eq!(mangle("Hello_World"), "__TURBOPACK__Hello_World__");
        assert_eq!(mangle("Hello__World"), "__TURBOPACK__Hello_$5f$World__");
        assert_eq!(mangle("Hello___World"), "__TURBOPACK__Hello_$5f$_World__");
        assert_eq!(mangle("Hello/World"), "__TURBOPACK__Hello$2f$World__");
        assert_eq!(mangle("Hello///World"), "__TURBOPACK__Hello$2f2f2f$World__");
        assert_eq!(mangle("Hello/_World"), "__TURBOPACK__Hello$2f$_World__");
        assert_eq!(mangle("Hello_/_World"), "__TURBOPACK__Hello_$2f$_World__");
        assert_eq!(mangle("Hello😀World"), "__TURBOPACK__Hello$_1f600$World__");
        assert_eq!(
            mangle("Hello/😀/World"),
            "__TURBOPACK__Hello$2f_1f600$$2f$World__"
        );
        assert_eq!(
            mangle("Hello😀😀World"),
            "__TURBOPACK__Hello$_1f600$$_1f600$World__"
        );
    }

    #[test]
    fn test_decode() {
        assert_eq!(unmangle("__TURBOPACK__Hello__World__"), "Hello World");
        assert_eq!(unmangle("__TURBOPACK__Hello_World__"), "Hello_World");
        assert_eq!(unmangle("__TURBOPACK__Hello_$5f$World__"), "Hello__World");
        assert_eq!(unmangle("__TURBOPACK__Hello_$5f$_World__"), "Hello___World");
        assert_eq!(unmangle("__TURBOPACK__Hello$2f$World__"), "Hello/World");
        assert_eq!(
            unmangle("__TURBOPACK__Hello$2f2f2f$World__"),
            "Hello///World"
        );
        assert_eq!(unmangle("__TURBOPACK__Hello$2f$_World__"), "Hello/_World");
        assert_eq!(unmangle("__TURBOPACK__Hello_$2f$_World__"), "Hello_/_World");
        assert_eq!(
            unmangle("__TURBOPACK__Hello$_1f600$World__"),
            "Hello😀World"
        );
        assert_eq!(
            unmangle("__TURBOPACK__Hello$2f_1f600$$2f$World__"),
            "Hello/😀/World"
        );
        assert_eq!(
            unmangle("__TURBOPACK__Hello$_1f600$$_1f600$World__"),
            "Hello😀😀World"
        );
    }

    #[test]
    fn test_unmangle_identifiers() {
        assert_eq!(
            unmangle_identifiers(
                "Hello __TURBOPACK__Hello__World__ __TURBOPACK__Hello_World__",
                |s| format!("{{{s}}}")
            ),
            "Hello {Hello World} {Hello_World}"
        );
    }
}