Add CommandNotFound error type for better exec command failure diagnostic (#448)

Author: soareschen

crates/runtime/runtime/src/impls/runtime/error.rs

@@ -6,7 +6,9 @@ use std::process::ExitStatus;
 use cgp::core::error::{ErrorRaiser, ProvideErrorType};
 use hermes_async_runtime_components::channel::types::ChannelClosedError;
 use hermes_tokio_runtime_components::impls::os::child_process::PrematureChildProcessExitError;
-use hermes_tokio_runtime_components::impls::os::exec_command::ExecCommandFailure;
+use hermes_tokio_runtime_components::impls::os::exec_command::{
+    CommandNotFound, ExecCommandFailure,
+};
 
 use crate::impls::runtime::components::HermesRuntimeComponents;
 use crate::types::error::TokioRuntimeError;
@@ -60,3 +62,9 @@ impl ErrorRaiser<HermesRuntime, ExecCommandFailure> for HermesRuntimeComponents
         }
     }
 }
+
+impl ErrorRaiser<HermesRuntime, CommandNotFound> for HermesRuntimeComponents {
+    fn raise_error(e: CommandNotFound) -> TokioRuntimeError {
+        TokioRuntimeError::CommandNotFound { command: e.command }
+    }
+}

crates/runtime/runtime/src/types/error.rs

@@ -1,11 +1,11 @@
 use alloc::sync::Arc;
-use core::fmt::Display;
+use core::fmt::{Debug, Display};
 use core::str::Utf8Error;
 use std::error::Error;
 use std::io::Error as IoError;
 use std::process::ExitStatus;
 
-#[derive(Clone, Debug)]
+#[derive(Clone)]
 pub enum TokioRuntimeError {
     ChannelClosed,
     PoisonedLock,
@@ -25,6 +25,9 @@ pub enum TokioRuntimeError {
         stdout: String,
         stderr: String,
     },
+    CommandNotFound {
+        command: String,
+    },
 }
 
 impl Display for TokioRuntimeError {
@@ -68,10 +71,23 @@ impl Display for TokioRuntimeError {
                     exit_status
                 )?;
             }
+            Self::CommandNotFound { command } => {
+                write!(
+                    f,
+                    "failed to execute command due to command not found: {}",
+                    command
+                )?;
+            }
         };
 
         Ok(())
     }
 }
 
+impl Debug for TokioRuntimeError {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        write!(f, "{self}")
+    }
+}
+
 impl Error for TokioRuntimeError {}

crates/runtime/tokio-runtime-components/src/impls/os/exec_command.rs

@@ -1,7 +1,7 @@
 use core::str;
 use core::str::Utf8Error;
 use std::ffi::OsStr;
-use std::io::Error as IoError;
+use std::io::{Error as IoError, ErrorKind};
 
 use cgp::prelude::*;
 use hermes_runtime_components::traits::fs::file_path::HasFilePathType;
@@ -17,11 +17,16 @@ pub struct ExecCommandFailure {
     pub stderr: String,
 }
 
+pub struct CommandNotFound {
+    pub command: String,
+}
+
 impl<Runtime> CommandWithEnvsExecutor<Runtime> for TokioExecCommand
 where
     Runtime: HasFilePathType
         + CanRaiseError<IoError>
         + CanRaiseError<Utf8Error>
+        + CanRaiseError<CommandNotFound>
         + CanRaiseError<ExecCommandFailure>,
     Runtime::FilePath: AsRef<OsStr>,
 {
@@ -37,7 +42,15 @@ where
             .kill_on_drop(true)
             .output()
             .await
-            .map_err(Runtime::raise_error)?;
+            .map_err(|e| {
+                if e.kind() == ErrorKind::NotFound {
+                    Runtime::raise_error(CommandNotFound {
+                        command: Runtime::file_path_to_string(command_path),
+                    })
+                } else {
+                    Runtime::raise_error(e)
+                }
+            })?;
 
         let stdout = str::from_utf8(&output.stdout).map_err(Runtime::raise_error)?;