http_types/other/
source_map.rs

1use crate::headers::{HeaderName, HeaderValue, Headers, SOURCE_MAP};
2use crate::{bail_status as bail, Status, Url};
3
4use std::convert::TryInto;
5
6/// Links to a file that maps transformed source to the original source.
7///
8/// [MDN Documentation](https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/SourceMap)
9///
10/// # Specifications
11///
12/// - [Source Map Revision 3](https://sourcemaps.info/spec.html)
13///
14/// # Examples
15///
16/// ```
17/// # fn main() -> http_types::Result<()> {
18/// #
19/// use http_types::{Response, Url};
20/// use http_types::other::SourceMap;
21///
22/// let source_map = SourceMap::new(Url::parse("https://example.net/")?);
23///
24/// let mut res = Response::new(200);
25/// source_map.apply(&mut res);
26///
27/// let base_url = Url::parse("https://example.net/")?;
28/// let source_map = SourceMap::from_headers(base_url, res)?.unwrap();
29/// assert_eq!(source_map.location(), &Url::parse("https://example.net/")?);
30/// #
31/// # Ok(()) }
32/// ```
33#[derive(Debug)]
34pub struct SourceMap {
35    location: Url,
36}
37
38impl SourceMap {
39    /// Create a new instance of `SourceMap` header.
40    pub fn new(location: Url) -> Self {
41        Self { location }
42    }
43
44    /// Create a new instance from headers.
45    pub fn from_headers<U>(base_url: U, headers: impl AsRef<Headers>) -> crate::Result<Option<Self>>
46    where
47        U: TryInto<Url>,
48        U::Error: std::fmt::Debug,
49    {
50        let headers = match headers.as_ref().get(SOURCE_MAP) {
51            Some(headers) => headers,
52            None => return Ok(None),
53        };
54
55        // If we successfully parsed the header then there's always at least one
56        // entry. We want the last entry.
57        let header_value = headers.iter().last().unwrap();
58
59        let url = match Url::parse(header_value.as_str()) {
60            Ok(url) => url,
61            Err(_) => match base_url.try_into() {
62                Ok(base_url) => base_url.join(header_value.as_str().trim()).status(500)?,
63                Err(_) => bail!(500, "Invalid base url provided"),
64            },
65        };
66
67        Ok(Some(Self { location: url }))
68    }
69
70    /// Sets the header.
71    pub fn apply(&self, mut headers: impl AsMut<Headers>) {
72        headers.as_mut().insert(self.name(), self.value());
73    }
74
75    /// Get the `HeaderName`.
76    pub fn name(&self) -> HeaderName {
77        SOURCE_MAP
78    }
79
80    /// Get the `HeaderValue`.
81    pub fn value(&self) -> HeaderValue {
82        let output = self.location.to_string();
83
84        // SAFETY: the internal string is validated to be ASCII.
85        unsafe { HeaderValue::from_bytes_unchecked(output.into()) }
86    }
87
88    /// Get the url.
89    pub fn location(&self) -> &Url {
90        &self.location
91    }
92
93    /// Set the url.
94    pub fn set_location<U>(&mut self, location: U) -> Result<(), U::Error>
95    where
96        U: TryInto<Url>,
97        U::Error: std::fmt::Debug,
98    {
99        self.location = location.try_into()?;
100        Ok(())
101    }
102}
103
104#[cfg(test)]
105mod test {
106    use super::*;
107    use crate::headers::Headers;
108
109    #[test]
110    fn smoke() -> crate::Result<()> {
111        let source_map = SourceMap::new(Url::parse("https://example.net/test.json")?);
112
113        let mut headers = Headers::new();
114        source_map.apply(&mut headers);
115
116        let base_url = Url::parse("https://example.net/")?;
117        let source_map = SourceMap::from_headers(base_url, headers)?.unwrap();
118        assert_eq!(
119            source_map.location(),
120            &Url::parse("https://example.net/test.json")?
121        );
122        Ok(())
123    }
124
125    #[test]
126    fn bad_request_on_parse_error() {
127        let mut headers = Headers::new();
128        headers.insert(SOURCE_MAP, "htt://<nori ate the tag. yum.>");
129        let err = SourceMap::from_headers(Url::parse("https://example.net").unwrap(), headers)
130            .unwrap_err();
131        assert_eq!(err.status(), 500);
132    }
133
134    #[test]
135    fn fallback_works() -> crate::Result<()> {
136        let mut headers = Headers::new();
137        headers.insert(SOURCE_MAP, "/test.json");
138
139        let base_url = Url::parse("https://fallback.net/")?;
140        let source_map = SourceMap::from_headers(base_url, headers)?.unwrap();
141        assert_eq!(
142            source_map.location(),
143            &Url::parse("https://fallback.net/test.json")?
144        );
145
146        let mut headers = Headers::new();
147        headers.insert(SOURCE_MAP, "https://example.com/test.json");
148
149        let base_url = Url::parse("https://fallback.net/")?;
150        let source_map = SourceMap::from_headers(base_url, headers)?.unwrap();
151        assert_eq!(
152            source_map.location(),
153            &Url::parse("https://example.com/test.json")?
154        );
155        Ok(())
156    }
157}
http_types/other/source_map.rs

http_types/other/
source_map.rs
