use 'thiserror' to define 'Error'

Cargo.toml

@@ -41,6 +41,7 @@ url = "2.1"
 # XXX: This is a temporary dependency for the reexport! macro in lib.rs. Remove
 # me before 0.9.0 is released.
 paste = "1.0"
+thiserror = "1.0.30"
 
 [dev-dependencies]
 env_logger = "0.8"

src/errors.rs

@@ -2,45 +2,42 @@
 
 use hyper::{self, http, StatusCode};
 use serde_json::Error as SerdeError;
-use std::{error::Error as StdError, fmt, string::FromUtf8Error};
+use std::string::FromUtf8Error;
 
 use futures_util::io::Error as IoError;
 
 /// Represents the result of all docker operations
 pub type Result<T> = std::result::Result<T, Error>;
 
-#[derive(Debug)]
+#[derive(Debug, thiserror::Error)]
 pub enum Error {
-    SerdeJsonError(SerdeError),
-    Hyper(hyper::Error),
-    Http(hyper::http::Error),
+    #[error(transparent)]
+    SerdeJsonError(#[from] SerdeError),
+
+    #[error(transparent)]
+    Hyper(#[from] hyper::Error),
+
+    #[error(transparent)]
+    Http(#[from] hyper::http::Error),
+
     #[allow(clippy::upper_case_acronyms)]
-    IO(IoError),
-    Encoding(FromUtf8Error),
+    #[error(transparent)]
+    IO(#[from] IoError),
+
+    #[error(transparent)]
+    Encoding(#[from] FromUtf8Error),
+
+    #[error("Response doesn't have the expected format: {0}")]
     InvalidResponse(String),
+
+    #[error("{code}: {message}")]
     Fault {
         code: StatusCode,
         message: String,
     },
-    ConnectionNotUpgraded,
-}
-
-impl From<SerdeError> for Error {
-    fn from(error: SerdeError) -> Error {
-        Error::SerdeJsonError(error)
-    }
-}
-
-impl From<hyper::Error> for Error {
-    fn from(error: hyper::Error) -> Error {
-        Error::Hyper(error)
-    }
-}
 
-impl From<hyper::http::Error> for Error {
-    fn from(error: hyper::http::Error) -> Error {
-        Error::Http(error)
-    }
+    #[error("expected the docker host to upgrade the HTTP connection but it did not")]
+    ConnectionNotUpgraded,
 }
 
 impl From<http::uri::InvalidUri> for Error {
@@ -49,51 +46,3 @@ impl From<http::uri::InvalidUri> for Error {
         http_error.into()
     }
 }
-
-impl From<IoError> for Error {
-    fn from(error: IoError) -> Error {
-        Error::IO(error)
-    }
-}
-
-impl From<FromUtf8Error> for Error {
-    fn from(error: FromUtf8Error) -> Error {
-        Error::Encoding(error)
-    }
-}
-
-impl fmt::Display for Error {
-    fn fmt(
-        &self,
-        f: &mut fmt::Formatter,
-    ) -> fmt::Result {
-        write!(f, "Docker Error: ")?;
-        match self {
-            Error::SerdeJsonError(ref err) => err.fmt(f),
-            Error::Http(ref err) => err.fmt(f),
-            Error::Hyper(ref err) => err.fmt(f),
-            Error::IO(ref err) => err.fmt(f),
-            Error::Encoding(ref err) => err.fmt(f),
-            Error::InvalidResponse(ref cause) => {
-                write!(f, "Response doesn't have the expected format: {}", cause)
-            }
-            Error::Fault { code, message } => write!(f, "{}: {}", code, message),
-            Error::ConnectionNotUpgraded => write!(
-                f,
-                "expected the docker host to upgrade the HTTP connection but it did not"
-            ),
-        }
-    }
-}
-
-impl StdError for Error {
-    fn source(&self) -> Option<&(dyn StdError + 'static)> {
-        match self {
-            Error::SerdeJsonError(ref err) => Some(err),
-            Error::Http(ref err) => Some(err),
-            Error::IO(ref err) => Some(err),
-            Error::Encoding(e) => Some(e),
-            _ => None,
-        }
-    }
-}