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

use std::error;
use std::fmt;
use std::result;

use crate::header;
use crate::method;
use crate::status;
use crate::uri;

/// A generic "error" for HTTP connections
///
/// This error type is less specific than the error returned from other
/// functions in this crate, but all other errors can be converted to this
/// error. Consumers of this crate can typically consume and work with this form
/// of error for conversions with the `?` operator.
pub struct Error {
    inner: ErrorKind,
}

/// A `Result` typedef to use with the `http::Error` type
pub type Result<T> = result::Result<T, Error>;

enum ErrorKind {
    StatusCode(status::InvalidStatusCode),
    Method(method::InvalidMethod),
    Uri(uri::InvalidUri),
    UriParts(uri::InvalidUriParts),
    HeaderName(header::InvalidHeaderName),
    HeaderValue(header::InvalidHeaderValue),
}

impl fmt::Debug for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        f.debug_tuple("http::Error")
            // Skip the noise of the ErrorKind enum
            .field(&self.get_ref())
            .finish()
    }
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        fmt::Display::fmt(self.get_ref(), f)
    }
}

impl Error {
    /// Return true if the underlying error has the same type as T.
    pub fn is<T: error::Error + 'static>(&self) -> bool {
        self.get_ref().is::<T>()
    }

    /// Return a reference to the lower level, inner error.
    pub fn get_ref(&self) -> &(dyn error::Error + 'static) {
        use self::ErrorKind::*;

        match self.inner {
            StatusCode(ref e) => e,
            Method(ref e) => e,
            Uri(ref e) => e,
            UriParts(ref e) => e,
            HeaderName(ref e) => e,
            HeaderValue(ref e) => e,
        }
    }
}

impl error::Error for Error {
    fn description(&self) -> &str {
        use self::ErrorKind::*;

        match self.inner {
            StatusCode(ref e) => e.description(),
            Method(ref e) => e.description(),
            Uri(ref e) => e.description(),
            UriParts(ref e) => e.description(),
            HeaderName(ref e) => e.description(),
            HeaderValue(ref e) => e.description(),
        }
    }

    // Return any available cause from the inner error. Note the inner error is
    // not itself the cause.
    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
        self.get_ref().source()
    }
}

impl From<status::InvalidStatusCode> for Error {
    fn from(err: status::InvalidStatusCode) -> Error {
        Error {
            inner: ErrorKind::StatusCode(err),
        }
    }
}

impl From<method::InvalidMethod> for Error {
    fn from(err: method::InvalidMethod) -> Error {
        Error {
            inner: ErrorKind::Method(err),
        }
    }
}

impl From<uri::InvalidUri> for Error {
    fn from(err: uri::InvalidUri) -> Error {
        Error {
            inner: ErrorKind::Uri(err),
        }
    }
}

impl From<uri::InvalidUriParts> for Error {
    fn from(err: uri::InvalidUriParts) -> Error {
        Error {
            inner: ErrorKind::UriParts(err),
        }
    }
}

impl From<header::InvalidHeaderName> for Error {
    fn from(err: header::InvalidHeaderName) -> Error {
        Error {
            inner: ErrorKind::HeaderName(err),
        }
    }
}

impl From<header::InvalidHeaderValue> for Error {
    fn from(err: header::InvalidHeaderValue) -> Error {
        Error {
            inner: ErrorKind::HeaderValue(err),
        }
    }
}

impl From<std::convert::Infallible> for Error {
    fn from(err: std::convert::Infallible) -> Error {
        match err {}
    }
}

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

    #[test]
    fn inner_error_is_invalid_status_code() {
        if let Err(e) = status::StatusCode::from_u16(6666) {
            let err: Error = e.into();
            let ie = err.get_ref();
            assert!(!ie.is::<header::InvalidHeaderValue>());
            assert!(ie.is::<status::InvalidStatusCode>());
            ie.downcast_ref::<status::InvalidStatusCode>().unwrap();

            assert!(!err.is::<header::InvalidHeaderValue>());
            assert!(err.is::<status::InvalidStatusCode>());
        } else {
            panic!("Bad status allowed!");
        }
    }
}