schemars/
encoding.rs

1use crate::_alloc_prelude::*;
2use alloc::borrow::Cow;
3use core::fmt::Write as _;
4
5/// Encodes a string for insertion into a JSON Pointer in URI fragment representation.
6#[must_use]
7pub fn encode_ref_name(name: &str) -> Cow<'_, str> {
8    fn needs_encoding(byte: u8) -> bool {
9        match byte {
10            // `~` and `/` need encoding for JSON Pointer
11            // See https://datatracker.ietf.org/doc/html/rfc6901#section-3
12            b'~' | b'/' => true,
13            // These chars (and `~`) are valid in URL fragment
14            // See https://datatracker.ietf.org/doc/html/rfc3986/#section-3.5
15            b'!' | b'$' | b'&'..=b';' | b'=' | b'?'..=b'Z' | b'_' | b'a'..=b'z' => false,
16            // Everything else needs percent-encoding
17            _ => true,
18        }
19    }
20
21    if name.bytes().any(needs_encoding) {
22        let mut buf = String::new();
23
24        for byte in name.bytes() {
25            if byte == b'~' {
26                buf.push_str("~0");
27            } else if byte == b'/' {
28                buf.push_str("~1");
29            } else if needs_encoding(byte) {
30                write!(buf, "%{byte:2X}").unwrap();
31            } else {
32                buf.push(byte as char);
33            }
34        }
35
36        Cow::Owned(buf)
37    } else {
38        Cow::Borrowed(name)
39    }
40}
41
42/// Percent-decodes the given string, returning `None` if it results in invalid UTF-8.
43/// A `%` that is not followed by two hex digits is treated as a literal `%`.
44#[must_use]
45pub fn percent_decode(s: &str) -> Option<Cow<'_, str>> {
46    if s.contains('%') {
47        let mut buf = Vec::<u8>::new();
48
49        let mut segments = s.split('%');
50        buf.extend(segments.next().unwrap_or_default().as_bytes());
51
52        for segment in segments {
53            if let Some(decoded_byte) = segment
54                .get(0..2)
55                .and_then(|p| u8::from_str_radix(p, 16).ok())
56            {
57                buf.push(decoded_byte);
58                buf.extend(&segment.as_bytes()[2..]);
59            } else {
60                buf.push(b'%');
61                buf.extend(segment.as_bytes());
62            }
63        }
64
65        String::from_utf8(buf).ok().map(Cow::Owned)
66    } else {
67        Some(Cow::Borrowed(s))
68    }
69}
70
71#[cfg(test)]
72mod tests {
73    use super::*;
74
75    #[test]
76    fn test_encode_ref_name() {
77        assert_eq!(encode_ref_name("Simple!"), "Simple!");
78        assert_eq!(
79            encode_ref_name("Needs %-encoding 🚀"),
80            "Needs%20%25-encoding%20%F0%9F%9A%80"
81        );
82        assert_eq!(
83            encode_ref_name("aA0-._!$&'()*+,;=:@?"),
84            "aA0-._!$&'()*+,;=:@?",
85        );
86        assert_eq!(encode_ref_name("\"£%^\\~/"), "%22%C2%A3%25%5E%5C~0~1",);
87    }
88
89    #[test]
90    fn test_percent_decode() {
91        assert_eq!(percent_decode("Simple!"), Some("Simple!".into()));
92        assert_eq!(
93            percent_decode("Needs %-encoding 🚀"),
94            Some("Needs %-encoding 🚀".into())
95        );
96        assert_eq!(
97            percent_decode("Needs%20%25-encoding%20%F0%9F%9A%80"),
98            Some("Needs %-encoding 🚀".into())
99        );
100        assert_eq!(
101            percent_decode("aA0-._!$&'()*+,;=:@?"),
102            Some("aA0-._!$&'()*+,;=:@?".into())
103        );
104        assert_eq!(percent_decode("\"£%^\\~/"), Some("\"£%^\\~/".into()));
105        assert_eq!(
106            percent_decode("%22%C2%A3%25%5E%5C~0~1"),
107            Some("\"£%^\\~0~1".into())
108        );
109        assert_eq!(percent_decode("%%%2020%%%"), Some("%% 20%%%".into()));
110        assert_eq!(percent_decode("%f0%9F%9a%80"), Some("🚀".into()));
111        assert_eq!(percent_decode("%F0%9F%9A"), None);
112    }
113}
schemars/encoding.rs

schemars/
encoding.rs
