Merge pull request #416 from eyakubovich/ey/err-on-unmatched-directive

Check for nested and unmatched directives

Author: Hendrik van Antwerpen

languages/tree-sitter-stack-graphs-typescript/build.rs

@@ -41,6 +41,10 @@ fn preprocess(
                 bail!("Line {line_no}: unexpected code before directive");
             }
 
+            if filter.is_some() {
+                bail!("Line {line_no}: dialect directive cannot be nested");
+            }
+
             let directive = captures.get(1).unwrap().as_str();
             if !DIALECTS.contains(&directive) {
                 bail!("Line {line_no}: unknown dialect: {directive}");
@@ -64,6 +68,10 @@ fn preprocess(
         output.write(b"\n")?;
     }
 
+    if filter.is_some() {
+        bail!("Unmatched directive end at the end of the file");
+    }
+
     Ok(())
 }