Fix and improve call_cmd_with_input, add tests.

src/utils.rs

@@ -4,13 +4,31 @@ use std::process::{Command, Stdio};
 
 pub fn call_cmd_with_input(cmd: &str, args: Vec<&str>, input: &str) -> io::Result<String> {
     let mut cmd = Command::new(cmd).args(args).stdin(Stdio::piped()).stdout(Stdio::piped()).spawn()?;
-    let stdin = cmd.stdin.as_mut().unwrap();
-    stdin.write_all(input.as_bytes())?;
+    let mut stdin = cmd.stdin.take().unwrap();
     let stdout = cmd.stdout.as_mut().unwrap();
+    let in_data = input.to_string();
+    let write_handle = std::thread::spawn(move || stdin.write_all(in_data.as_bytes()));
     let mut output = Vec::new();
     stdout.read_to_end(&mut output)?;
+    match write_handle.join() {
+        Ok(_) => (),
+        Err(_) => return Err(io::Error::new(io::ErrorKind::Other, "Failed to run command")),
+    }
     match String::from_utf8(output) {
         Ok(x) => Ok(x),
         Err(err) => Err(io::Error::new(io::ErrorKind::InvalidData, err.utf8_error())),
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn cmd_exec_test() {
+        assert_eq!(call_cmd_with_input("true", vec![], "").unwrap(), "".to_string());
+        assert_eq!(call_cmd_with_input("cat", vec![], "ok").unwrap(), "ok".to_string());
+        assert_ne!(call_cmd_with_input("cat", vec![], "notok").unwrap(), "ok".to_string());
+        assert_eq!(call_cmd_with_input("echo", vec!["-n", "test is ok"], "").unwrap(), "test is ok".to_string());
+    }
+}