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

//! The HTTP request method
use std::fmt;
use std::str::FromStr;
use std::convert::AsRef;

use error::Error;
use self::Method::{Options, Get, Post, Put, Delete, Head, Trace, Connect, Patch,
                   Extension};

/// The Request Method (VERB)
///
/// Currently includes 8 variants representing the 8 methods defined in
/// [RFC 7230](https://tools.ietf.org/html/rfc7231#section-4.1), plus PATCH,
/// and an Extension variant for all extensions.
///
/// It may make sense to grow this to include all variants currently
/// registered with IANA, if they are at all common to use.
#[derive(Clone, PartialEq, Eq, Hash, Debug)]
pub enum Method {
    /// OPTIONS
    Options,
    /// GET
    Get,
    /// POST
    Post,
    /// PUT
    Put,
    /// DELETE
    Delete,
    /// HEAD
    Head,
    /// TRACE
    Trace,
    /// CONNECT
    Connect,
    /// PATCH
    Patch,
    /// Method extensions. An example would be `let m = Extension("FOO".to_string())`.
    Extension(String)
}

impl AsRef<str> for Method {
    fn as_ref(&self) -> &str {
        match *self {
            Options => "OPTIONS",
            Get => "GET",
            Post => "POST",
            Put => "PUT",
            Delete => "DELETE",
            Head => "HEAD",
            Trace => "TRACE",
            Connect => "CONNECT",
            Patch => "PATCH",
            Extension(ref s) => s.as_ref()
        }
    }
}

impl Method {
    /// Whether a method is considered "safe", meaning the request is
    /// essentially read-only.
    ///
    /// See [the spec](https://tools.ietf.org/html/rfc7231#section-4.2.1)
    /// for more words.
    pub fn safe(&self) -> bool {
        match *self {
            Get | Head | Options | Trace => true,
            _ => false
        }
    }

    /// Whether a method is considered "idempotent", meaning the request has
    /// the same result is executed multiple times.
    ///
    /// See [the spec](https://tools.ietf.org/html/rfc7231#section-4.2.2) for
    /// more words.
    pub fn idempotent(&self) -> bool {
        if self.safe() {
            true
        } else {
            match *self {
                Put | Delete => true,
                _ => false
            }
        }
    }
}

impl FromStr for Method {
    type Err = Error;
    fn from_str(s: &str) -> Result<Method, Error> {
        if s == "" {
            Err(Error::Method)
        } else {
            Ok(match s {
                "OPTIONS" => Options,
                "GET" => Get,
                "POST" => Post,
                "PUT" => Put,
                "DELETE" => Delete,
                "HEAD" => Head,
                "TRACE" => Trace,
                "CONNECT" => Connect,
                "PATCH" => Patch,
                _ => Extension(s.to_owned())
            })
        }
    }
}

impl fmt::Display for Method {
    fn fmt(&self, fmt: &mut fmt::Formatter) -> fmt::Result {
        fmt.write_str(match *self {
            Options => "OPTIONS",
            Get => "GET",
            Post => "POST",
            Put => "PUT",
            Delete => "DELETE",
            Head => "HEAD",
            Trace => "TRACE",
            Connect => "CONNECT",
            Patch => "PATCH",
            Extension(ref s) => s.as_ref()
        })
    }
}

#[cfg(test)]
mod tests {
    use std::collections::HashMap;
    use std::str::FromStr;
    use error::Error;
    use super::Method;
    use super::Method::{Get, Post, Put, Extension};

    #[test]
    fn test_safe() {
        assert_eq!(true, Get.safe());
        assert_eq!(false, Post.safe());
    }

    #[test]
    fn test_idempotent() {
        assert_eq!(true, Get.idempotent());
        assert_eq!(true, Put.idempotent());
        assert_eq!(false, Post.idempotent());
    }

    #[test]
    fn test_from_str() {
        assert_eq!(Get, FromStr::from_str("GET").unwrap());
        assert_eq!(Extension("MOVE".to_owned()),
                   FromStr::from_str("MOVE").unwrap());
        let x: Result<Method, _> = FromStr::from_str("");
        if let Err(Error::Method) = x {
        } else {
            panic!("An empty method is invalid!")
        }
    }

    #[test]
    fn test_fmt() {
        assert_eq!("GET".to_owned(), format!("{}", Get));
        assert_eq!("MOVE".to_owned(),
                   format!("{}", Extension("MOVE".to_owned())));
    }

    #[test]
    fn test_hashable() {
        let mut counter: HashMap<Method,usize> = HashMap::new();
        counter.insert(Get, 1);
        assert_eq!(Some(&1), counter.get(&Get));
    }

    #[test]
    fn test_as_str() {
        assert_eq!(Get.as_ref(), "GET");
        assert_eq!(Post.as_ref(), "POST");
        assert_eq!(Put.as_ref(), "PUT");
        assert_eq!(Extension("MOVE".to_owned()).as_ref(), "MOVE");
    }
}