better error on OS watcher limit, #207

src/lib.rs

@@ -2,18 +2,20 @@ extern crate notify;
 extern crate pyo3;
 
 use std::collections::HashSet;
+use std::io::ErrorKind as IOErrorKind;
 use std::path::Path;
 use std::sync::{Arc, Mutex};
 use std::thread::sleep;
 use std::time::{Duration, SystemTime};
 
 use pyo3::create_exception;
-use pyo3::exceptions::{PyFileNotFoundError, PyRuntimeError, PyTypeError};
+use pyo3::exceptions::{PyFileNotFoundError, PyOSError, PyPermissionError, PyRuntimeError, PyTypeError};
 use pyo3::prelude::*;
 
 use notify::event::{Event, EventKind, ModifyKind, RenameMode};
 use notify::{
- Config as NotifyConfig, ErrorKind, PollWatcher, RecommendedWatcher, RecursiveMode, Result as NotifyResult, Watcher,
+ Config as NotifyConfig, ErrorKind as NotifyErrorKind, ErrorKind, PollWatcher, RecommendedWatcher, RecursiveMode,
+ Result as NotifyResult, Watcher,
 };
 
 create_exception!(
@@ -43,6 +45,19 @@ struct RustNotify {
  watcher: WatcherEnum,
 }
 
+fn map_watch_error(error: notify::Error) -> PyErr {
+ let err_string = error.to_string();
+ match error.kind {
+ NotifyErrorKind::PathNotFound => PyFileNotFoundError::new_err(err_string),
+ NotifyErrorKind::Io(io_error) => match io_error.kind() {
+ IOErrorKind::NotFound => PyFileNotFoundError::new_err(err_string),
+ IOErrorKind::PermissionDenied => PyPermissionError::new_err(err_string),
+ _ => PyOSError::new_err(err_string),
+ },
+ _ => PyOSError::new_err(err_string),
+ }
+}
+
 // macro to avoid duplicated code below
 macro_rules! watcher_paths {
  ($watcher:ident, $paths:ident, $debug:ident, $recursive:ident) => {
@@ -52,9 +67,7 @@ macro_rules! watcher_paths {
  RecursiveMode::NonRecursive
  };
  for watch_path in $paths.into_iter() {
- $watcher
- .watch(Path::new(&watch_path), mode)
- .map_err(|e| PyFileNotFoundError::new_err(format!("{}", e)))?;
+ $watcher.watch(Path::new(&watch_path), mode).map_err(map_watch_error)?;
  }
  if $debug {
  eprintln!("watcher: {:?}", $watcher);
@@ -167,7 +180,7 @@ impl RustNotify {
  }
  Err(error) => {
  match &error.kind {
- ErrorKind::Io(io_error) => {
+ NotifyErrorKind::Io(io_error) => {
  if io_error.raw_os_error() == Some(38) {
  // see https://github.com/samuelcolvin/watchfiles/issues/167
  // we callback to PollWatcher

tests/test_rust_notify.py

@@ -147,7 +147,7 @@ def test_move_internal(test_dir: Path):
 
 def test_does_not_exist(tmp_path: Path):
  p = tmp_path / 'missing'
- with pytest.raises(FileNotFoundError):
+ with pytest.raises(FileNotFoundError, match='No such file or directory'):
  RustNotify([str(p)], False, False, 0, True)