Merge pull request #4 from blorbb/fix/ra-source-path

fix invalid path by rust-analyzer causing panic

internal/stylance-macros/src/lib.rs

@@ -66,13 +66,17 @@ fn try_import_style_classes_rel(input: &LitStr) -> anyhow::Result<TokenStream> {
         env::var_os("CARGO_MANIFEST_DIR").context("CARGO_MANIFEST_DIR env var not found")?;
     let manifest_path = Path::new(&manifest_dir_env);
 
-    let call_site_path = proc_macro::Span::call_site().source().source_file().path();
-    let file_path = call_site_path
-        .parent()
-        .expect("No current path")
-        .join(input.value());
-
-    try_import_style_classes_with_path(manifest_path, &file_path, input.span())
+    let source_path = proc_macro::Span::call_site().source().source_file().path();
+    // rust-analyzer gives a source file with `.is_real() == true`
+    // but the path itself is just "".
+    // assume that an empty path means that rust-analyzer is running this
+    // and expand to nothing.
+    let Some(parent) = source_path.parent() else {
+        return Ok(TokenStream::new());
+    };
+    let css_path = parent.join(input.value());
+
+    try_import_style_classes_with_path(manifest_path, &css_path, input.span())
 }
 
 #[cfg(feature = "nightly")]