fix(semantic): correctly resolve identifiers inside parameter initializers (#3046)

close: #2644
This fixes function parameters. I think we need an extra AST node to fix catch parameters, which will be the next PR.

crates/oxc_semantic/src/builder.rs

@@ -284,10 +284,22 @@ impl<'a> SemanticBuilder<'a> {
         Some(symbol_id)
     }
 
-    pub fn declare_reference(&mut self, reference: Reference) -> ReferenceId {
+    pub fn declare_reference(
+        &mut self,
+        reference: Reference,
+        add_unresolved_reference: bool,
+    ) -> ReferenceId {
         let reference_name = reference.name().clone();
         let reference_id = self.symbols.create_reference(reference);
-        self.scope.add_unresolved_reference(self.current_scope_id, reference_name, reference_id);
+        if add_unresolved_reference {
+            self.scope.add_unresolved_reference(
+                self.current_scope_id,
+                reference_name,
+                reference_id,
+            );
+        } else {
+            self.resolve_reference_ids(reference_name.clone(), vec![reference_id]);
+        }
         reference_id
     }
 
@@ -313,18 +325,22 @@ impl<'a> SemanticBuilder<'a> {
             .drain()
             .collect::<Vec<(_, Vec<_>)>>();
 
+        for (name, reference_ids) in all_references {
+            self.resolve_reference_ids(name, reference_ids);
+        }
+    }
+
+    fn resolve_reference_ids(&mut self, name: CompactStr, reference_ids: Vec<ReferenceId>) {
         let parent_scope_id =
             self.scope.get_parent_id(self.current_scope_id).unwrap_or(self.current_scope_id);
 
-        for (name, reference_ids) in all_references {
+        if let Some(symbol_id) = self.scope.get_binding(self.current_scope_id, &name) {
-            if let Some(symbol_id) = self.scope.get_binding(self.current_scope_id, &name) {
+            for reference_id in &reference_ids {
-                for reference_id in &reference_ids {
+                self.symbols.references[*reference_id].set_symbol_id(symbol_id);
-                    self.symbols.references[*reference_id].set_symbol_id(symbol_id);
-                }
-                self.symbols.resolved_references[symbol_id].extend(reference_ids);
-            } else {
-                self.scope.extend_unresolved_reference(parent_scope_id, name, reference_ids);
             }
+            self.symbols.resolved_references[symbol_id].extend(reference_ids);
+        } else {
+            self.scope.extend_unresolved_reference(parent_scope_id, name, reference_ids);
         }
     }
 
@@ -1710,6 +1726,7 @@ impl<'a> SemanticBuilder<'a> {
                 element.bind(self);
             }
             AstKind::FormalParameters(_) => {
+                self.current_node_flags |= NodeFlags::Parameter;
                 self.remove_export_flag();
             }
             AstKind::FormalParameter(param) => {
@@ -1815,6 +1832,9 @@ impl<'a> SemanticBuilder<'a> {
             AstKind::ArrowFunctionExpression(_) => {
                 self.function_stack.pop();
             }
+            AstKind::FormalParameters(_) => {
+                self.current_node_flags -= NodeFlags::Parameter;
+            }
             AstKind::TSModuleBlock(_) => {
                 self.namespace_stack.pop();
             }
@@ -1864,9 +1884,13 @@ impl<'a> SemanticBuilder<'a> {
 
     fn reference_identifier(&mut self, ident: &IdentifierReference) {
         let flag = self.resolve_reference_usages();
-        let reference =
+        let name = ident.name.to_compact_str();
-            Reference::new(ident.span, ident.name.to_compact_str(), self.current_node_id, flag);
+        let reference = Reference::new(ident.span, name.clone(), self.current_node_id, flag);
-        let reference_id = self.declare_reference(reference);
+        // `function foo({bar: identifier_reference}) {}`
+        //                     ^^^^^^^^^^^^^^^^^^^^ Parameter initializer must be resolved immediately
+        //                                          to avoid binding to variables inside the scope
+        let add_unresolved_reference = !self.current_node_flags.has_parameter();
+        let reference_id = self.declare_reference(reference, add_unresolved_reference);
         ident.reference_id.set(Some(reference_id));
     }
 
@@ -1897,7 +1921,7 @@ impl<'a> SemanticBuilder<'a> {
             self.current_node_id,
             ReferenceFlag::read(),
         );
-        self.declare_reference(reference);
+        self.declare_reference(reference, true);
     }
 
     fn is_not_expression_statement_parent(&self) -> bool {

crates/oxc_semantic/tests/scopes.rs

@@ -106,3 +106,18 @@ fn test_switch_case() {
     .has_number_of_references(1)
     .test();
 }
+
+#[test]
+fn test_function_parameters() {
+    SemanticTester::js(
+        "
+            const foo = 2;
+            function func(a = foo, b = a) {
+                const foo = 0;
+            }
+        ",
+    )
+    .has_root_symbol("foo")
+    .has_number_of_references(1)
+    .test();
+}

crates/oxc_syntax/src/node.rs

@@ -13,29 +13,38 @@ export type NodeFlags = {
     JSDoc: 1,
     Class: 2,
     HasYield: 4
+    Parameter: 8
 };
 "#;
 
 bitflags! {
     #[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
     pub struct NodeFlags: u8 {
-        const JSDoc    = 1 << 0; // If the Node has a JSDoc comment attached
+        const JSDoc     = 1 << 0; // If the Node has a JSDoc comment attached
-        const Class    = 1 << 1; // If Node is inside a class
+        const Class     = 1 << 1; // If Node is inside a class
-        const HasYield = 1 << 2; // If function has yield statement
+        const HasYield  = 1 << 2; // If function has yield statement
-
+        const Parameter = 1 << 3; // If Node is inside a parameter
     }
 }
 
 impl NodeFlags {
+    #[inline]
     pub fn has_jsdoc(&self) -> bool {
         self.contains(Self::JSDoc)
     }
 
+    #[inline]
     pub fn has_class(&self) -> bool {
         self.contains(Self::Class)
     }
 
+    #[inline]
     pub fn has_yield(&self) -> bool {
         self.contains(Self::HasYield)
     }
+
+    #[inline]
+    pub fn has_parameter(&self) -> bool {
+        self.contains(Self::Parameter)
+    }
 }