1 files changed, 149 insertions, 0 deletions
diff --git a/third_party/rust/http/src/error.rs b/third_party/rust/http/src/error.rs
new file mode 100644
index 0000000000..ba690841b6
--- /dev/null
+++ b/third_party/rust/http/src/error.rs
@@ -0,0 +1,149 @@
+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 {
+    // 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!");
+        }
+    }
+}