feat: Return 1 if no dirs are found

A better error code

src/main.rs

@@ -307,8 +307,12 @@ fn main() {
         indicator.stop();
 
         let print_errors = config.get_print_errors(&options);
-        print_any_errors(print_errors, walk_data.errors);
+        let final_errors = walk_data.errors.lock().unwrap();
+        print_any_errors(print_errors, &final_errors);
 
+        if tree.children.is_empty() && !final_errors.file_not_found.is_empty() {
+            std::process::exit(1)
+        } else {
             print_output(
                 config,
                 options,
@@ -317,6 +321,7 @@ fn main() {
                 is_colors,
                 terminal_width,
             )
+        }
     });
 }
 
@@ -357,8 +362,7 @@ fn print_output(
     }
 }
 
-fn print_any_errors(print_errors: bool, errors: Arc<Mutex<RuntimeErrors>>) {
-    let final_errors = errors.lock().unwrap();
+fn print_any_errors(print_errors: bool, final_errors: &RuntimeErrors) {
     if !final_errors.file_not_found.is_empty() {
         let err = final_errors
             .file_not_found

tests/test_flags.rs

@@ -107,7 +107,9 @@ pub fn test_ignore_all_in_file() {
 #[test]
 pub fn test_with_bad_param() {
     let mut cmd = Command::cargo_bin("dust").unwrap();
-    let result = cmd.arg("bad_place").unwrap();
+    cmd.arg("-P").arg("bad_place");
+    let output_error = cmd.unwrap_err();
+    let result = output_error.as_output().unwrap();
     let stderr = str::from_utf8(&result.stderr).unwrap();
     assert!(stderr.contains("No such file or directory"));
 }