improve errors management

src/output.rs

@@ -1,69 +1,26 @@
+use error_chain::error_chain;
 use serde::Serialize;
-use std::{
-    fmt::{self, Display},
-    io,
-    process::Command,
-    result, string,
-};
+use std::{fmt::Display, process::Command};
 
-// Error wrapper
-
-#[derive(Debug)]
-pub enum Error {
-    IoError(io::Error),
-    ParseUtf8Error(string::FromUtf8Error),
-    SerializeJsonError(serde_json::Error),
-}
-
-impl fmt::Display for Error {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "input: ")?;
-
-        match self {
-            Error::IoError(err) => err.fmt(f),
-            Error::ParseUtf8Error(err) => err.fmt(f),
-            Error::SerializeJsonError(err) => err.fmt(f),
-        }
-    }
-}
-
-impl From<io::Error> for Error {
-    fn from(err: io::Error) -> Error {
-        Error::IoError(err)
-    }
-}
-
-impl From<string::FromUtf8Error> for Error {
-    fn from(err: string::FromUtf8Error) -> Error {
-        Error::ParseUtf8Error(err)
-    }
-}
-
-impl From<serde_json::Error> for Error {
-    fn from(err: serde_json::Error) -> Error {
-        Error::SerializeJsonError(err)
-    }
-}
-
-// Result wrapper
-
-type Result<T> = result::Result<T, Error>;
-
-// Utils
+error_chain! {}
 
 pub fn run_cmd(cmd: &str) -> Result<String> {
     let output = if cfg!(target_os = "windows") {
-        Command::new("cmd").args(&["/C", cmd]).output()?
+        Command::new("cmd").args(&["/C", cmd]).output()
     } else {
-        Command::new("sh").arg("-c").arg(cmd).output()?
-    };
+        Command::new("sh").arg("-c").arg(cmd).output()
+    }
+    .chain_err(|| "Run command failed")?;
 
-    Ok(String::from_utf8(output.stdout)?)
+    Ok(String::from_utf8(output.stdout).chain_err(|| "Invalid utf8 output")?)
 }
 
 pub fn print<T: Display + Serialize>(output_type: &str, item: T) -> Result<()> {
     match output_type {
-        "json" => print!("{}", serde_json::to_string(&item)?),
+        "json" => print!(
+            "{}",
+            serde_json::to_string(&item).chain_err(|| "Invalid JSON string")?
+        ),
         "text" | _ => println!("{}", item.to_string()),
     }