tauri_utils/
mime_type.rs

1// Copyright 2019-2024 Tauri Programme within The Commons Conservancy
2// SPDX-License-Identifier: Apache-2.0
3// SPDX-License-Identifier: MIT
4
5//! Determine a mime type from a URI or file contents.
6
7use std::fmt;
8
9const MIMETYPE_PLAIN: &str = "text/plain";
10
11/// [Web Compatible MimeTypes](https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types#important_mime_types_for_web_developers)
12#[allow(missing_docs)]
13pub enum MimeType {
14  Css,
15  Csv,
16  Html,
17  Ico,
18  Js,
19  Json,
20  Jsonld,
21  Mp4,
22  OctetStream,
23  Rtf,
24  Svg,
25  Txt,
26}
27
28impl std::fmt::Display for MimeType {
29  fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
30    let mime = match self {
31      MimeType::Css => "text/css",
32      MimeType::Csv => "text/csv",
33      MimeType::Html => "text/html",
34      MimeType::Ico => "image/vnd.microsoft.icon",
35      MimeType::Js => "text/javascript",
36      MimeType::Json => "application/json",
37      MimeType::Jsonld => "application/ld+json",
38      MimeType::Mp4 => "video/mp4",
39      MimeType::OctetStream => "application/octet-stream",
40      MimeType::Rtf => "application/rtf",
41      MimeType::Svg => "image/svg+xml",
42      MimeType::Txt => MIMETYPE_PLAIN,
43    };
44    write!(f, "{mime}")
45  }
46}
47
48impl MimeType {
49  /// parse a URI suffix to convert text/plain mimeType to their actual web compatible mimeType.
50  pub fn parse_from_uri(uri: &str) -> MimeType {
51    Self::parse_from_uri_with_fallback(uri, Self::Html)
52  }
53
54  /// parse a URI suffix to convert text/plain mimeType to their actual web compatible mimeType with specified fallback for unknown file extensions.
55  pub fn parse_from_uri_with_fallback(uri: &str, fallback: MimeType) -> MimeType {
56    let suffix = uri.split('.').last();
57    match suffix {
58      Some("bin") => Self::OctetStream,
59      Some("css" | "less" | "sass" | "styl") => Self::Css,
60      Some("csv") => Self::Csv,
61      Some("html") => Self::Html,
62      Some("ico") => Self::Ico,
63      Some("js") => Self::Js,
64      Some("json") => Self::Json,
65      Some("jsonld") => Self::Jsonld,
66      Some("mjs") => Self::Js,
67      Some("mp4") => Self::Mp4,
68      Some("rtf") => Self::Rtf,
69      Some("svg") => Self::Svg,
70      Some("txt") => Self::Txt,
71      // Assume HTML when a TLD is found for eg. `wry:://tauri.app` | `wry://hello.com`
72      Some(_) => fallback,
73      // using octet stream according to this:
74      // <https://developer.mozilla.org/en-US/docs/Web/HTTP/Basics_of_HTTP/MIME_types/Common_types>
75      None => Self::OctetStream,
76    }
77  }
78
79  /// infer mimetype from content (or) URI if needed.
80  pub fn parse(content: &[u8], uri: &str) -> String {
81    Self::parse_with_fallback(content, uri, Self::Html)
82  }
83  /// infer mimetype from content (or) URI if needed with specified fallback for unknown file extensions.
84  pub fn parse_with_fallback(content: &[u8], uri: &str, fallback: MimeType) -> String {
85    let mime = if uri.ends_with(".svg") {
86      // when reading svg, we can't use `infer`
87      None
88    } else {
89      infer::get(content).map(|info| info.mime_type())
90    };
91
92    match mime {
93      Some(mime) if mime == MIMETYPE_PLAIN => {
94        Self::parse_from_uri_with_fallback(uri, fallback).to_string()
95      }
96      None => Self::parse_from_uri_with_fallback(uri, fallback).to_string(),
97      Some(mime) => mime.to_string(),
98    }
99  }
100}
101
102#[cfg(test)]
103mod tests {
104  use super::*;
105
106  #[test]
107  fn should_parse_mimetype_from_uri() {
108    let css = MimeType::parse_from_uri(
109      "https://unpkg.com/browse/bootstrap@4.1.0/dist/css/bootstrap-grid.css",
110    )
111    .to_string();
112    assert_eq!(css, "text/css".to_string());
113
114    let csv: String = MimeType::parse_from_uri("https://example.com/random.csv").to_string();
115    assert_eq!(csv, "text/csv".to_string());
116
117    let ico: String =
118      MimeType::parse_from_uri("https://icons.duckduckgo.com/ip3/microsoft.com.ico").to_string();
119    assert_eq!(ico, String::from("image/vnd.microsoft.icon"));
120
121    let html: String = MimeType::parse_from_uri("https://tauri.app/index.html").to_string();
122    assert_eq!(html, String::from("text/html"));
123
124    let js: String =
125      MimeType::parse_from_uri("https://unpkg.com/react@17.0.1/umd/react.production.min.js")
126        .to_string();
127    assert_eq!(js, "text/javascript".to_string());
128
129    let json: String =
130      MimeType::parse_from_uri("https://unpkg.com/browse/react@17.0.1/build-info.json").to_string();
131    assert_eq!(json, String::from("application/json"));
132
133    let jsonld: String = MimeType::parse_from_uri("https:/example.com/hello.jsonld").to_string();
134    assert_eq!(jsonld, String::from("application/ld+json"));
135
136    let mjs: String = MimeType::parse_from_uri("https://example.com/bundled.mjs").to_string();
137    assert_eq!(mjs, String::from("text/javascript"));
138
139    let mp4: String = MimeType::parse_from_uri("https://example.com/video.mp4").to_string();
140    assert_eq!(mp4, String::from("video/mp4"));
141
142    let rtf: String = MimeType::parse_from_uri("https://example.com/document.rtf").to_string();
143    assert_eq!(rtf, String::from("application/rtf"));
144
145    let svg: String = MimeType::parse_from_uri("https://example.com/picture.svg").to_string();
146    assert_eq!(svg, String::from("image/svg+xml"));
147
148    let txt: String = MimeType::parse_from_uri("https://example.com/file.txt").to_string();
149    assert_eq!(txt, String::from("text/plain"));
150
151    let custom_scheme = MimeType::parse_from_uri("wry://tauri.app").to_string();
152    assert_eq!(custom_scheme, String::from("text/html"));
153  }
154}
tauri_utils/mime_type.rs

tauri_utils/
mime_type.rs
