remove unneeded unwraps

Note, this slightly changes the pub API, so it should require a minor
version bump at least.

There is still an `unwrap` in a `Drop` where it's unclear if it
can happen or it can be handled better (maybe just ignored?) and
an `expect` in a function where the expect should not happen (it's
checked before), and I didn't consider that it's worth adding a new
Error kind for this in particular.

Signed-off-by: Petre Eftime <petre.eftime@gmail.com>

Author: petreeftime

README.md

@@ -149,7 +149,5 @@ rust stable, beta and nightly on both Linux or Mac.
 
 - use [nix](https://github.com/nix-rust/nix) (and avoid libc wherever possible)
   to keep the code safe and clean
-- sadly, `expect` is used in rust too prominently to unwrap `Option`s and
-  `Result`s, use `exp_*` instead
 
 Licensed under [MIT License](LICENSE)

src/process.rs

@@ -126,10 +126,10 @@ impl PtyProcess {
     }
 
     /// Get handle to pty fork for reading/writing
-    pub fn get_file_handle(&self) -> File {
+    pub fn get_file_handle(&self) -> Result<File, Error> {
         // needed because otherwise fd is closed both by dropping process and reader/writer
-        let fd = dup(self.pty.as_raw_fd()).unwrap();
-        unsafe { File::from_raw_fd(fd) }
+        let fd = dup(self.pty.as_raw_fd())?;
+        unsafe { Ok(File::from_raw_fd(fd)) }
     }
 
     /// At the drop of PtyProcess the running process is killed. This is blocking forever if
@@ -230,14 +230,13 @@ impl Drop for PtyProcess {
 mod tests {
     use super::*;
     use nix::sys::{signal, wait};
-    use std::io::prelude::*;
-    use std::io::{BufReader, LineWriter};
+    use std::io::{BufRead, BufReader, LineWriter, Write};
 
     #[test]
     /// Open cat, write string, read back string twice, send Ctrl^C and check that cat exited
     fn test_cat() -> std::io::Result<()> {
         let process = PtyProcess::new(Command::new("cat")).expect("could not execute cat");
-        let f = process.get_file_handle();
+        let f = process.get_file_handle().unwrap();
         let mut writer = LineWriter::new(&f);
         let mut reader = BufReader::new(&f);
         let _ = writer.write(b"hello cat\n")?;

src/session.rs

@@ -192,7 +192,7 @@ impl DerefMut for PtySession {
 /// ```
 impl PtySession {
     fn new(process: PtyProcess, timeout_ms: Option<u64>) -> Result<Self, Error> {
-        let f = process.get_file_handle();
+        let f = process.get_file_handle()?;
         let reader = f.try_clone()?;
         let stream = StreamSession::new(reader, f, timeout_ms);
         Ok(Self { process, stream })
@@ -373,16 +373,14 @@ pub fn spawn_bash(timeout: Option<u64>) -> Result<PtyReplSession, Error> {
     // wait for the first prompt since we don't know what .bashrc
     // would set as PS1 and we cannot know when is the right time
     // to set the new PS1
-    let mut rcfile = tempfile::NamedTempFile::new().unwrap();
-    let _ = rcfile
-        .write(
-            b"include () { [[ -f \"$1\" ]] && source \"$1\"; }\n\
+    let mut rcfile = tempfile::NamedTempFile::new()?;
+    let _ = rcfile.write(
+        b"include () { [[ -f \"$1\" ]] && source \"$1\"; }\n\
                   include /etc/bash.bashrc\n\
                   include ~/.bashrc\n\
                   PS1=\"~~~~\"\n\
                   unset PROMPT_COMMAND\n",
-        )
-        .expect("cannot write to tmpfile");
+    )?;
     let mut c = Command::new("bash");
     c.args(&[
         "--rcfile",