fix: add fsEvent notify::Error casts (denoland#4488)

cli/js/tests/fs_events_test.ts

@@ -14,6 +14,26 @@ unitTest({ perms: { read: false } }, function fsEventsPermissions() {
   assert(thrown);
 });
 
+unitTest({ perms: { read: true } }, function fsEventsInvalidPath() {
+  let thrown = false;
+  try {
+    Deno.fsEvents("non-existant.file");
+  } catch (err) {
+    console.error(err);
+    if (Deno.build.os === "win") {
+      assert(
+        err.message.includes(
+          "Input watch path is neither a file nor a directory"
+        )
+      );
+    } else {
+      assert(err instanceof Deno.errors.NotFound);
+    }
+    thrown = true;
+  }
+  assert(thrown);
+});
+
 async function getTwoEvents(
   iter: AsyncIterableIterator<Deno.FsEvent>
 ): Promise<Deno.FsEvent[]> {

cli/op_error.rs

@@ -18,6 +18,7 @@ use crate::import_map::ImportMapError;
 use deno_core::ErrBox;
 use deno_core::ModuleResolutionError;
 use dlopen;
+use notify;
 use reqwest;
 use rustyline::error::ReadlineError;
 use std;
@@ -349,6 +350,30 @@ impl From<&dlopen::Error> for OpError {
   }
 }
 
+impl From<notify::Error> for OpError {
+  fn from(error: notify::Error) -> Self {
+    OpError::from(&error)
+  }
+}
+
+impl From<&notify::Error> for OpError {
+  fn from(error: &notify::Error) -> Self {
+    use notify::ErrorKind::*;
+    let kind = match error.kind {
+      Generic(_) => ErrorKind::Other,
+      Io(ref e) => return e.into(),
+      PathNotFound => ErrorKind::NotFound,
+      WatchNotFound => ErrorKind::NotFound,
+      InvalidConfig(_) => ErrorKind::InvalidData,
+    };
+
+    Self {
+      kind,
+      msg: error.to_string(),
+    }
+  }
+}
+
 impl From<ErrBox> for OpError {
   fn from(error: ErrBox) -> Self {
     #[cfg(unix)]
@@ -384,6 +409,7 @@ impl From<ErrBox> for OpError {
           .map(|e| e.into())
       })
       .or_else(|| error.downcast_ref::<dlopen::Error>().map(|e| e.into()))
+      .or_else(|| error.downcast_ref::<notify::Error>().map(|e| e.into()))
       .or_else(|| unix_error_kind(&error))
       .unwrap_or_else(|| {
         panic!("Can't downcast {:?} to OpError", error);