process: Fix clippy warnings

src/bin/cat.rs

@@ -10,10 +10,10 @@ fn main() {
     loop {
         line.clear();
         stdin.read_line(&mut line).unwrap();
-        if line.len() == 0 {
+        if line.is_empty() {
             break;
         }
-        stdout.write(line.as_bytes()).unwrap();
+        stdout.write_all(line.as_bytes()).unwrap();
     }
     stdout.flush().unwrap();
 }

src/lib.rs

@@ -319,15 +319,21 @@ pub trait CommandExt {
     fn output_async_with_handle(&mut self, handle: &Handle) -> OutputAsync;
 }
 
+struct SpawnedChild {
+    child: imp::Child,
+    stdin: Option<imp::ChildStdin>,
+    stdout: Option<imp::ChildStdout>,
+    stderr: Option<imp::ChildStderr>,
+}
 
 impl CommandExt for Command {
     fn spawn_async_with_handle(&mut self, handle: &Handle) -> io::Result<Child> {
-        imp::Child::new(self.spawn()?, handle)
-            .map(|(child, stdin, stdout, stderr)| Child {
-                child,
-                stdin: stdin.map(|inner| ChildStdin { inner }),
-                stdout: stdout.map(|inner| ChildStdout { inner }),
-                stderr: stderr.map(|inner| ChildStderr { inner }),
+        imp::spawn_child(self, handle)
+            .map(|spawned_child| Child {
+                child: spawned_child.child,
+                stdin: spawned_child.stdin.map(|inner| ChildStdin { inner }),
+                stdout: spawned_child.stdout.map(|inner| ChildStdout { inner }),
+                stderr: spawned_child.stderr.map(|inner| ChildStderr { inner }),
                 kill_on_drop: true,
             })
     }
@@ -353,7 +359,7 @@ impl CommandExt for Command {
 
         let inner = self.spawn_async_with_handle(handle)
             .into_future()
-            .and_then(|c| c.wait_with_output());
+            .and_then(Child::wait_with_output);
 
         OutputAsync {
             inner: Box::new(inner),
@@ -445,9 +451,9 @@ impl Child {
         WaitWithOutput {
             inner: Box::new(self.join3(stdout, stderr).map(|(status, stdout, stderr)| {
                 Output {
-                    status: status,
-                    stdout: stdout,
-                    stderr: stderr,
+                    status,
+                    stdout,
+                    stderr,
                 }
             }))
         }

src/unix/mod.rs

@@ -38,6 +38,7 @@ use std::fmt;
 use std::io;
 use std::os::unix::io::{AsRawFd, RawFd};
 use std::process::{self, ExitStatus};
+use super::SpawnedChild;
 use tokio_io::IoFuture;
 use tokio_reactor::{Handle, PollEvented};
 
@@ -66,21 +67,24 @@ impl fmt::Debug for Child {
     }
 }
 
+pub(crate) fn spawn_child(cmd: &mut process::Command, handle: &Handle) -> io::Result<SpawnedChild> {
+    let mut child = cmd.spawn()?;
+    let stdin = stdio(child.stdin.take(), handle)?;
+    let stdout = stdio(child.stdout.take(), handle)?;
+    let stderr = stdio(child.stderr.take(), handle)?;
+
+    let signal = Signal::with_handle(libc::SIGCHLD, handle).flatten_stream();
+    Ok(SpawnedChild {
+        child: Child {
+            inner: Reaper::new(child, signal),
+        },
+        stdin,
+        stdout,
+        stderr,
+    })
+}
+
 impl Child {
-    pub fn new(mut inner: process::Child, handle: &Handle)
-        -> io::Result<(Child, Option<ChildStdin>, Option<ChildStdout>, Option<ChildStderr>)>
-    {
-        let stdin = stdio(inner.stdin.take(), handle)?;
-        let stdout = stdio(inner.stdout.take(), handle)?;
-        let stderr = stdio(inner.stderr.take(), handle)?;
-
-        let signal = Signal::with_handle(libc::SIGCHLD, handle).flatten_stream();
-        let child = Child {
-            inner: Reaper::new(inner, signal),
-        };
-
-        Ok((child, stdin, stdout, stderr))
-    }
 
     pub fn id(&self) -> u32 {
         self.inner.id()

src/unix/reap.rs

@@ -124,7 +124,7 @@ mod test {
     impl Wait for MockWait {
         fn try_wait(&mut self) -> io::Result<Option<ExitStatus>> {
             let ret = if self.num_wait_until_status == self.total_waits {
-                Some(self.status.clone())
+                Some(self.status)
             } else {
                 None
             };
@@ -171,7 +171,7 @@ mod test {
     #[test]
     fn reaper() {
         let exit = ExitStatus::from_raw(0);
-        let mock = MockWait::new(exit.clone(), 3);
+        let mock = MockWait::new(exit, 3);
         let mut grim = Reaper::new(mock, MockStream::new(vec!(
             None,
             Some(()),

src/windows.rs

@@ -23,6 +23,7 @@ use std::io;
 use std::os::windows::prelude::*;
 use std::os::windows::process::ExitStatusExt;
 use std::process::{self, ExitStatus};
+use std::ptr;
 
 use futures::future::Fuse;
 use futures::sync::oneshot;
@@ -36,6 +37,7 @@ use self::winapi::um::synchapi::*;
 use self::winapi::um::threadpoollegacyapiset::*;
 use self::winapi::um::winbase::*;
 use self::winapi::um::winnt::*;
+use super::SpawnedChild;
 use tokio_reactor::{Handle, PollEvented};
 
 #[must_use = "futures do nothing unless polled"]
@@ -63,22 +65,24 @@ struct Waiting {
 unsafe impl Sync for Waiting {}
 unsafe impl Send for Waiting {}
 
-impl Child {
-    pub fn new(mut inner: process::Child, handle: &Handle)
-        -> io::Result<(Child, Option<ChildStdin>, Option<ChildStdout>, Option<ChildStderr>)>
-    {
-        let stdin = stdio(inner.stdin.take(), handle)?;
-        let stdout = stdio(inner.stdout.take(), handle)?;
-        let stderr = stdio(inner.stderr.take(), handle)?;
+pub(crate) fn spawn_child(cmd: &mut process::Command, handle: &Handle) -> io::Result<SpawnedChild> {
+    let mut child = cmd.spawn()?;
+    let stdin = stdio(child.stdin.take(), handle)?;
+    let stdout = stdio(child.stdout.take(), handle)?;
+    let stderr = stdio(child.stderr.take(), handle)?;
 
-        let child = Child {
-            child: inner,
+    Ok(SpawnedChild {
+        child: Child {
+            child,
             waiting: None,
-        };
-
-        Ok((child, stdin, stdout, stderr))
-    }
+        },
+        stdin,
+        stdout,
+        stderr,
+    })
+}
 
+impl Child {
     pub fn id(&self) -> u32 {
         self.child.id()
     }
@@ -103,7 +107,7 @@ impl Child {
             }
             let (tx, rx) = oneshot::channel();
             let ptr = Box::into_raw(Box::new(Some(tx)));
-            let mut wait_object = 0 as *mut _;
+            let mut wait_object = ptr::null_mut();
             let rc = unsafe {
                 RegisterWaitForSingleObject(&mut wait_object,
                                             self.child.as_raw_handle(),
@@ -120,7 +124,7 @@ impl Child {
             }
             self.waiting = Some(Waiting {
                 rx: rx.fuse(),
-                wait_object: wait_object,
+                wait_object,
                 tx: ptr,
             });
         }
@@ -142,7 +146,7 @@ impl Drop for Waiting {
 unsafe extern "system" fn callback(ptr: PVOID,
                                    _timer_fired: BOOLEAN) {
     let complete = &mut *(ptr as *mut Option<oneshot::Sender<()>>);
-    drop(complete.take().unwrap().send(()));
+    let _ = complete.take().unwrap().send(());
 }
 
 pub fn try_wait(child: &process::Child) -> io::Result<Option<ExitStatus>> {

tests/issue_42.rs

@@ -16,7 +16,7 @@ fn run_test() {
     let finished_clone = finished.clone();
 
     thread::spawn(move || {
-        let _ = stream::iter_ok((0..2).into_iter())
+        let _ = stream::iter_ok(0..2)
             .map(|i| Command::new("echo")
                  .arg(format!("I am spawned process #{}", i))
                  .stdin(Stdio::null())

tests/stdio.rs

@@ -36,7 +36,7 @@ fn feed_cat(mut cat: Child, n: usize) -> Box<Future<Item = ExitStatus, Error = i
     // Try to read `n + 1` lines, ensuring the last one is empty
     // (i.e. EOF is reached after `n` lines.
     let reader = io::BufReader::new(stdout);
-    let expected_numbers = stream::iter_ok(0..n + 1);
+    let expected_numbers = stream::iter_ok(0..=n);
     let read = expected_numbers.fold((reader, 0), move |(reader, i), _| {
         let done = i >= n;
         debug!("starting read from child");