Move emscripten-tests to tests dir + misc fixes

lib/dev-utils/src/stdio.rs

@@ -1,5 +1,6 @@
 use super::file_descriptor::FileDescriptor;
 use libc;
+use std::io;
 use std::io::BufReader;
 use std::io::Read;
 
@@ -21,39 +22,76 @@ const STDOUT_FILENO: libc::c_int = 1;
 #[cfg(target_os = "windows")]
 const STDERR_FILENO: libc::c_int = 2;
 
+fn pipe(ptr: *mut libc::c_int) -> Result<libc::c_int, io::Error> {
+    #[cfg(not(target_os = "windows"))]
+    let result = unsafe { libc::pipe(ptr) };
+    #[cfg(target_os = "windows")]
+    let result = unsafe { libc::pipe(ptr, 1000, libc::O_TEXT) };
+
+    if result == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(result)
+    }
+}
+
+/// `dup` creates a new `fd`, make sure you `close` it when you're done with it!!
+fn dup(oldfd: libc::c_int) -> Result<libc::c_int, io::Error> {
+    let result = unsafe { libc::dup(oldfd) };
+
+    if result == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(result)
+    }
+}
+
+fn dup2(oldfd: libc::c_int, newfd: libc::c_int) -> Result<libc::c_int, io::Error> {
+    let result = unsafe { libc::dup2(oldfd, newfd) };
+
+    if result == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(result)
+    }
+}
+
+fn close(fd: libc::c_int) -> Result<libc::c_int, io::Error> {
+    let result = unsafe { libc::close(fd) };
+
+    if result == -1 {
+        Err(std::io::Error::last_os_error())
+    } else {
+        Ok(result)
+    }
+}
+
 // Implementation inspired in
 // https://github.com/rust-lang/rust/blob/7d52cbce6db83e4fc2d8706b4e4b9c7da76cbcf8/src/test/run-pass/issues/issue-30490.rs
 // Currently only works in Unix systems (Mac, Linux)
 impl StdioCapturer {
     fn pipe() -> (libc::c_int, libc::c_int) {
         let mut fds = [0; 2];
-
-        #[cfg(not(target_os = "windows"))]
-        assert_eq!(unsafe { libc::pipe(fds.as_mut_ptr()) }, 0);
-        #[cfg(target_os = "windows")]
-        assert_eq!(
-            unsafe { libc::pipe(fds.as_mut_ptr(), 1000, libc::O_TEXT) },
-            0
-        );
+        pipe(fds.as_mut_ptr()).unwrap();
 
         (fds[0], fds[1])
     }
 
     pub fn new() -> Self {
-        let stdout_backup = unsafe { libc::dup(STDOUT_FILENO) };
-        let stderr_backup = unsafe { libc::dup(STDERR_FILENO) };
+        let stdout_backup = dup(STDOUT_FILENO).unwrap();
+        let stderr_backup = dup(STDERR_FILENO).unwrap();
 
         let (stdout_reader, stdout_writer) = Self::pipe();
         let (stderr_reader, stderr_writer) = Self::pipe();
 
-        assert!(unsafe { libc::dup2(stdout_writer, STDOUT_FILENO) } > -1);
-        assert!(unsafe { libc::dup2(stderr_writer, STDERR_FILENO) } > -1);
+        dup2(stdout_writer, STDOUT_FILENO).unwrap();
+        dup2(stderr_writer, STDERR_FILENO).unwrap();
 
         // Make sure we close any duplicates of the writer end of the pipe,
         // otherwise we can get stuck reading from the pipe which has open
         // writers but no one supplying any input
-        assert_eq!(unsafe { libc::close(stdout_writer) }, 0);
-        assert_eq!(unsafe { libc::close(stderr_writer) }, 0);
+        close(stdout_writer).unwrap();
+        close(stderr_writer).unwrap();
 
         StdioCapturer {
             stdout_backup,
@@ -64,11 +102,11 @@ impl StdioCapturer {
     }
 
     pub fn end(self) -> Result<(String, String), std::io::Error> {
-        // The Stdio passed into the Command took over (and closed) std{out, err}
-        // so we should restore them as they were.
+        dup2(self.stdout_backup, STDOUT_FILENO).unwrap();
+        dup2(self.stderr_backup, STDERR_FILENO).unwrap();
 
-        assert!(unsafe { libc::dup2(self.stdout_backup, STDOUT_FILENO) } > -1);
-        assert!(unsafe { libc::dup2(self.stderr_backup, STDERR_FILENO) } > -1);
+        close(self.stdout_backup).unwrap();
+        close(self.stderr_backup).unwrap();
 
         let fd = FileDescriptor::new(self.stdout_reader);
         let mut reader = BufReader::new(fd);