Make CTParserBuilder error on test_files with matchless glob.

Author: ratmice

lrlex/src/lib/ctbuilder.rs

@@ -561,9 +561,16 @@ where
                                 match setting {
                                     Setting::String(test_files, _) => {
                                         let path_joined = grm_path.parent().unwrap().join(test_files);
-                                        for path in
-                                            glob(&path_joined.to_string_lossy()).map_err(|e| e.to_string())?
-                                        {
+                                        let path_str = &path_joined.to_string_lossy();
+                                        let mut glob_paths = glob(path_str).map_err(|e| e.to_string())?.peekable();
+                                        if glob_paths.peek().is_none() {
+                                            return Err(format!("'test_files' glob '{}' matched no paths", path_str)
+                                                .to_string()
+                                                .into(),
+                                            );
+                                        }
+
+                                        for path in glob_paths {
                                             let path = path?;
                                             if let Some(ext) = path.extension() {
                                                 if let Some(ext) = ext.to_str() {

lrpar/cttests/src/ctfails/test_files3.test

@@ -0,0 +1,16 @@
+name: Test empty matchless glob in array of %grmtools{test_files}
+grammar: |
+    %grmtools {
+        yacckind: Original(YaccOriginalActionKind::UserAction),
+        recoverer: RecoveryKind::None,
+        test_files: ["*.nonexistent"]
+    }
+    %start Expr
+    %actiontype ()
+    %%
+    Expr: '(' ')' { () } ;
+lexer: |
+    %%
+    \( "("
+    \) ")"
+    [\t\n ]+ ;