Scaffold NSE support

crates/oak_db/src/imports.rs

@@ -2,6 +2,8 @@ use aether_path::FilePath;
 use camino::Utf8Component;
 use camino::Utf8Path;
 use camino::Utf8PathBuf;
+use oak_semantic::effects_registry;
+use oak_semantic::Effects;
 use oak_semantic::ImportsResolver;
 use oak_semantic::SourceResolution;
 use url::Url;
@@ -83,6 +85,22 @@ impl<'db> ImportsResolver for SalsaImportsResolver<'db> {
             packages,
         })
     }
+
+    fn resolve_effects(
+        &mut self,
+        name: &str,
+        _attached: &[String],
+        _lazy: bool,
+    ) -> Option<Effects> {
+        // Base is the always-attached layer at the bottom of the search path,
+        // resolved through the same registry lookup as any package.
+        //
+        // TODO!: walk the rest of the search path too (flow-order attaches,
+        // package siblings via `who_defines`, NAMESPACE imports, re-export chase).
+        effects_registry::lookup("base", name)
+            .copied()
+            .map(Effects::nse)
+    }
 }
 
 /// Anchor directory for relative `source("path")` arguments.

crates/oak_db/src/tests/file.rs

@@ -140,6 +140,31 @@ fn test_semantic_index_matches_oak_semantic() {
     assert_eq!(via_salsa, &direct);
 }
 
+#[test]
+fn test_semantic_index_recognizes_bare_base_nse() {
+    // Base NSE resolves through the real `SalsaImportsResolver` (base-only
+    // `resolve_effects`): a bare `local()` still pushes a nested NSE scope, so
+    // `x` lands there rather than at file scope.
+    use oak_semantic::semantic_index::NseScope;
+    use oak_semantic::semantic_index::NseTiming;
+    use oak_semantic::semantic_index::ScopeId;
+    use oak_semantic::semantic_index::ScopeKind;
+
+    let mut db = TestDb::new();
+    let file = new_file(&mut db, "a.R", "local({\n    x <- 1\n})\n");
+
+    let index = file.semantic_index(&db);
+    let file_scope = ScopeId::from(0);
+    let local_scope = ScopeId::from(1);
+
+    assert_eq!(
+        index.scope(local_scope).kind(),
+        ScopeKind::Nse(NseScope::Nested, NseTiming::Eager)
+    );
+    assert!(index.symbols(file_scope).get("x").is_none());
+    assert!(index.symbols(local_scope).get("x").is_some());
+}
+
 #[test]
 fn test_semantic_index_backdates_on_equivalent_content_set() {
     let mut db = TestDb::new();

crates/oak_db/src/tests/resolver.rs

@@ -198,9 +198,8 @@ fn test_closure_capture_with_source_before_function() {
     let bindings = fn_map.bindings_at_use(use_id);
     assert!(bindings.may_be_unbound());
 
-    let symbol = index.uses(fn_scope)[use_id].symbol();
     let (enclosing_scope, enclosing_bindings) = index
-        .enclosing_bindings(fn_scope, symbol)
+        .enclosing_bindings(fn_scope, use_id)
         .expect("`helper` should have an enclosing snapshot at the file scope");
     assert_eq!(enclosing_scope, file_scope);
     assert!(!enclosing_bindings.definitions().is_empty());
@@ -321,8 +320,7 @@ fn test_closure_capture_with_source_after_function() {
     let fn_scope = ScopeId::from(1);
 
     let use_id = oak_semantic::UseId::from(0);
-    let symbol = index.uses(fn_scope)[use_id].symbol();
-    assert!(index.enclosing_bindings(fn_scope, symbol).is_some());
+    assert!(index.enclosing_bindings(fn_scope, use_id).is_some());
 }
 
 #[test]