Replace error-chain with thiserror

This patch replaces error-chain with the current version of thiserror.
There's nothing done more, so no cleanup of .expect() or .unwrap()
calls, just a plain conversion from one crate to another.

Signed-off-by: Matthias Beyer <[email protected]>

Author: matthiasbeyer

Cargo.toml

@@ -16,8 +16,8 @@ readme      = "README.md"
 [dependencies]
 nix = "0.14"
 regex = "1"
-error-chain = "0.12"
 tempfile = "3"
+thiserror = "1.0.34"
 
 [badges]
 maintenance = { status = "passively-maintained" }

src/error.rs

@@ -1,29 +1,39 @@
 use std::time;
 
-error_chain::error_chain! {
-    errors {
-        EOF(expected:String, got:String, exit_code:Option<String>) {
-            description("End of filestream (usually stdout) occurred, most probably\
-                         because the process terminated")
-            display("EOF (End of File): Expected {} but got EOF after reading \"{}\", \
-                         process terminated with {:?}", expected, got,
-                         exit_code.as_ref()
-                         .unwrap_or(& "unknown".to_string()))
-        }
-        BrokenPipe {
-            description("The pipe to the process is broken. Most probably because\
-            the process died.")
-            display("PipeError")
-        }
-        Timeout(expected:String, got:String, timeout:time::Duration) {
-            description("The process didn't end within the given timeout")
-            display("Timeout Error: Expected {} but got \"{}\" (after waiting {} ms)",
-                    expected, got, (timeout.as_secs() * 1000) as u32
-                    + timeout.subsec_millis())
-        }
-        EmptyProgramName {
-            description("The provided program name is empty.")
-            display("EmptyProgramName")
-        }
-    }
+#[derive(Debug, thiserror::Error)]
+pub enum Error {
+    #[error("EOF (End of File): Expected {} but got EOF after reading \"{}\" process terminated with {:?}", .expected, .got, .exit_code.as_ref().unwrap_or(&"unknown".to_string()))]
+    EOF {
+        expected: String,
+        got: String,
+        exit_code: Option<String>,
+    },
+
+    #[error("PipeError")]
+    BrokenPipe,
+
+    #[error("Timeout Error: Expected {} but got \"{}\" (after waiting {} ms)", .expected, .got, (.timeout.as_secs() * 1000) as u32 + .timeout.subsec_millis())]
+    Timeout {
+        expected: String,
+        got: String,
+        timeout: time::Duration,
+    },
+
+    #[error("The provided program name is empty.")]
+    EmptyProgramName,
+
+    #[error(transparent)]
+    Nix(#[from] nix::Error),
+
+    #[error(transparent)]
+    Io(#[from] std::io::Error),
+
+    #[error("Did not understand Ctrl-{}", .0)]
+    SendContolError(char),
+
+    #[error("Failed to send via MPSC channel")]
+    MpscSendError,
+
+    #[error(transparent)]
+    Regex(#[from] regex::Error),
 }

src/process.rs

@@ -1,6 +1,6 @@
 //! Start a process via pty
 
-use crate::error::*;
+use crate::error::Error;
 use nix;
 use nix::fcntl::{open, OFlag};
 use nix::libc::{STDERR_FILENO, STDIN_FILENO, STDOUT_FILENO};
@@ -13,7 +13,7 @@ use std::fs::File;
 use std::os::unix::io::{AsRawFd, FromRawFd};
 use std::os::unix::process::CommandExt;
 use std::process::Command;
-use std::{thread, time}; // load error-chain
+use std::{thread, time};
 
 /// Start a process in a forked tty so you can interact with it the same as you would
 /// within a terminal
@@ -87,7 +87,7 @@ fn ptsname_r(fd: &PtyMaster) -> nix::Result<String> {
 
 impl PtyProcess {
     /// Start a process in a forked pty
-    pub fn new(mut command: Command) -> Result<Self> {
+    pub fn new(mut command: Command) -> Result<Self, Error> {
         || -> nix::Result<Self> {
             // Open a new PTY master
             let master_fd = posix_openpt(OFlag::O_RDWR)?;
@@ -128,7 +128,7 @@ impl PtyProcess {
                 }),
             }
         }()
-        .chain_err(|| format!("could not execute {:?}", command))
+        .map_err(Error::from)
     }
 
     /// Get handle to pty fork for reading/writing
@@ -177,19 +177,18 @@ impl PtyProcess {
 
     /// Wait until process has exited. This is a blocking call.
     /// If the process doesn't terminate this will block forever.
-    pub fn wait(&self) -> Result<wait::WaitStatus> {
-        wait::waitpid(self.child_pid, None).chain_err(|| "wait: cannot read status")
+    pub fn wait(&self) -> Result<wait::WaitStatus, Error> {
+        wait::waitpid(self.child_pid, None).map_err(Error::from)
     }
 
     /// Regularly exit the process, this method is blocking until the process is dead
-    pub fn exit(&mut self) -> Result<wait::WaitStatus> {
-        self.kill(signal::SIGTERM)
+    pub fn exit(&mut self) -> Result<wait::WaitStatus, Error> {
+        self.kill(signal::SIGTERM).map_err(Error::from)
     }
 
     /// Non-blocking variant of `kill()` (doesn't wait for process to be killed)
-    pub fn signal(&mut self, sig: signal::Signal) -> Result<()> {
-        signal::kill(self.child_pid, sig).chain_err(|| "failed to send signal to process")?;
-        Ok(())
+    pub fn signal(&mut self, sig: signal::Signal) -> Result<(), Error> {
+        signal::kill(self.child_pid, sig).map_err(Error::from)
     }
 
     /// Kill the process with a specific signal. This method blocks, until the process is dead
@@ -200,7 +199,7 @@ impl PtyProcess {
     ///
     /// if `kill_timeout` is set and a repeated sending of signal does not result in the process
     /// being killed, then `kill -9` is sent after the `kill_timeout` duration has elapsed.
-    pub fn kill(&mut self, sig: signal::Signal) -> Result<wait::WaitStatus> {
+    pub fn kill(&mut self, sig: signal::Signal) -> Result<wait::WaitStatus, Error> {
         let start = time::Instant::now();
         loop {
             match signal::kill(self.child_pid, sig) {
@@ -209,7 +208,7 @@ impl PtyProcess {
                 Err(nix::Error::Sys(nix::errno::Errno::ESRCH)) => {
                     return Ok(wait::WaitStatus::Exited(Pid::from_raw(0), 0))
                 }
-                Err(e) => return Err(format!("kill resulted in error: {:?}", e).into()),
+                Err(e) => return Err(Error::from(e)),
             }
 
             match self.status() {
@@ -219,7 +218,7 @@ impl PtyProcess {
             // kill -9 if timout is reached
             if let Some(timeout) = self.kill_timeout {
                 if start.elapsed() > timeout {
-                    signal::kill(self.child_pid, signal::Signal::SIGKILL).chain_err(|| "")?
+                    signal::kill(self.child_pid, signal::Signal::SIGKILL).map_err(Error::from)?
                 }
             }
         }

src/reader.rs

@@ -1,6 +1,6 @@
 //! Unblocking reader which supports waiting for strings/regexes and EOF to be present
 
-use crate::error::*; // load error-chain
+use crate::error::Error;
 pub use regex::Regex;
 use std::io::prelude::*;
 use std::io::{self, BufReader};
@@ -120,22 +120,20 @@ impl NBReader {
 
         // spawn a thread which reads one char and sends it to tx
         thread::spawn(move || {
-            let _ = || -> Result<()> {
+            let _ = || -> Result<(), Error> {
                 let mut reader = BufReader::new(f);
                 let mut byte = [0u8];
                 loop {
                     match reader.read(&mut byte) {
                         Ok(0) => {
-                            tx.send(Ok(PipedChar::EOF)).chain_err(|| "cannot send")?;
+                            tx.send(Ok(PipedChar::EOF)).map_err(|_| Error::MpscSendError)?;
                             break;
                         }
                         Ok(_) => {
-                            tx.send(Ok(PipedChar::Char(byte[0])))
-                                .chain_err(|| "cannot send")?;
+                            tx.send(Ok(PipedChar::Char(byte[0]))).map_err(|_| Error::MpscSendError)?;
                         }
                         Err(error) => {
-                            tx.send(Err(PipeError::IO(error)))
-                                .chain_err(|| "cannot send")?;
+                            tx.send(Err(PipeError::IO(error))).map_err(|_| Error::MpscSendError)?;
                         }
                     }
                 }
@@ -155,7 +153,7 @@ impl NBReader {
     }
 
     /// reads all available chars from the read channel and stores them in self.buffer
-    fn read_into_buffer(&mut self) -> Result<()> {
+    fn read_into_buffer(&mut self) -> Result<(), Error> {
         if self.eof {
             return Ok(());
         }
@@ -222,7 +220,7 @@ impl NBReader {
     /// assert_eq!("?", &until_end);
     /// ```
     ///
-    pub fn read_until(&mut self, needle: &ReadUntil) -> Result<(String, String)> {
+    pub fn read_until(&mut self, needle: &ReadUntil) -> Result<(String, String), Error> {
         let start = time::Instant::now();
 
         loop {
@@ -237,22 +235,25 @@ impl NBReader {
             // we don't know the reason of eof yet, so we provide an empty string
             // this will be filled out in session::exp()
             if self.eof {
-                return Err(ErrorKind::EOF(needle.to_string(), self.buffer.clone(), None).into());
+                return Err(Error::EOF {
+                    expected: needle.to_string(),
+                    got: self.buffer.clone(),
+                    exit_code: None,
+                });
             }
 
             // ran into timeout
             if let Some(timeout) = self.timeout {
                 if start.elapsed() > timeout {
-                    return Err(ErrorKind::Timeout(
-                        needle.to_string(),
-                        self.buffer
+                    return Err(Error::Timeout {
+                        expected: needle.to_string(),
+                        got: self.buffer
                             .clone()
                             .replace('\n', "`\\n`\n")
                             .replace('\r', "`\\r`")
                             .replace('\u{1b}', "`^`"),
                         timeout,
-                    )
-                    .into());
+                    });
                 }
             }
             // nothing matched: wait a little
@@ -289,8 +290,8 @@ mod tests {
         // check for EOF
         match r.read_until(&ReadUntil::NBytes(10)) {
             Ok(_) => panic!(),
-            Err(Error(ErrorKind::EOF(_, _, _), _)) => {}
-            Err(Error(_, _)) => panic!(),
+            Err(Error::EOF { .. }) => {}
+            Err(_) => panic!(),
         }
     }