refactor(semantic): add binder for FormalParameters and RestElement, …

…replacing the binder for FormalParameters (#2114)

Similar with #2013.

This way we will be able to find the corresponding Ast accurately.

The snapshots look a little strange but the change is expected.

crates/oxc_ast/src/ast/js.rs

@@ -1648,6 +1648,12 @@ pub enum FormalParameterKind {
     Signature,
 }
 
+impl FormalParameterKind {
+    pub fn is_signature(&self) -> bool {
+        matches!(self, Self::Signature)
+    }
+}
+
 impl<'a> FormalParameters<'a> {
     pub fn is_empty(&self) -> bool {
         self.items.is_empty()

crates/oxc_linter/src/rules/eslint/no_redeclare.rs

@@ -86,12 +86,10 @@ impl Rule for NoRedeclare {
                         }
                     }
                 }
-                AstKind::FormalParameters(params) => {
-                    for item in &params.items {
-                        if let BindingPatternKind::BindingIdentifier(ident) = &item.pattern.kind {
-                            if *symbol_table.get_name(variable.symbol_id) == ident.name {
-                                self.report_diagnostic(ctx, variable, ident);
-                            }
+                AstKind::FormalParameter(param) => {
+                    if let BindingPatternKind::BindingIdentifier(ident) = &param.pattern.kind {
+                        if *symbol_table.get_name(variable.symbol_id) == ident.name {
+                            self.report_diagnostic(ctx, variable, ident);
                         }
                     }
                 }

crates/oxc_linter/src/rules/oxc/no_accumulating_spread.rs

@@ -89,8 +89,10 @@ impl Rule for NoAccumulatingSpread {
         let reference = symbols.get_reference(reference_id);
         let Some(referenced_symbol_id) = reference.symbol_id() else { return };
         let declaration_id = symbols.get_declaration(referenced_symbol_id);
-        let declaration = ctx.semantic().nodes().get_node(declaration_id);
-        let AstKind::FormalParameters(params) = declaration.kind() else { return };
+        let Some(declaration) = ctx.semantic().nodes().parent_node(declaration_id) else { return };
+        let AstKind::FormalParameters(params) = declaration.kind() else {
+            return;
+        };
 
         // We're only looking for the first parameter, since that's where acc is.
         // Skip non-parameter or non-first-parameter declarations.

crates/oxc_semantic/src/binder.rs

@@ -182,13 +182,42 @@ impl<'a> Binder for Function<'a> {
     }
 }
 
-impl<'a> Binder for FormalParameters<'a> {
-    // Binds the formal parameters of a function or method.
+impl<'a> Binder for RestElement<'a> {
+    // Binds the FormalParameters's rest of a function or method.
     fn bind(&self, builder: &mut SemanticBuilder) {
+        let parent_kind = builder.nodes.parent_kind(builder.current_node_id).unwrap();
+        let AstKind::FormalParameters(parameters) = parent_kind else {
+            return;
+        };
+
+        if parameters.kind.is_signature() {
+            return;
+        }
+
+        let includes = SymbolFlags::FunctionScopedVariable;
+        let excludes =
+            SymbolFlags::FunctionScopedVariable | SymbolFlags::FunctionScopedVariableExcludes;
+        self.bound_names(&mut |ident| {
+            let symbol_id = builder.declare_symbol(ident.span, &ident.name, includes, excludes);
+            ident.symbol_id.set(Some(symbol_id));
+        });
+    }
+}
+
+impl<'a> Binder for FormalParameter<'a> {
+    // Binds the FormalParameter of a function or method.
+    fn bind(&self, builder: &mut SemanticBuilder) {
+        let parent_kind = builder.nodes.parent_kind(builder.current_node_id).unwrap();
+        let AstKind::FormalParameters(parameters) = parent_kind else { unreachable!() };
+
+        if parameters.kind.is_signature() {
+            return;
+        }
+
         let includes = SymbolFlags::FunctionScopedVariable;
 
         let is_not_allowed_duplicate_parameters = matches!(
-                self.kind,
+                parameters.kind,
                 // ArrowFormalParameters: UniqueFormalParameters
                 FormalParameterKind::ArrowFormalParameters |
                 // UniqueFormalParameters : FormalParameters
@@ -199,20 +228,18 @@ impl<'a> Binder for FormalParameters<'a> {
             builder.strict_mode() ||
             // FormalParameters : FormalParameterList
             // * It is a Syntax Error if IsSimpleParameterList of FormalParameterList is false and BoundNames of FormalParameterList contains any duplicate elements.
-            !self.is_simple_parameter_list();
+            !parameters.is_simple_parameter_list();
 
         let excludes = if is_not_allowed_duplicate_parameters {
             SymbolFlags::FunctionScopedVariable | SymbolFlags::FunctionScopedVariableExcludes
         } else {
             SymbolFlags::FunctionScopedVariableExcludes
         };
-        let is_signature = self.kind == FormalParameterKind::Signature;
-        if !is_signature {
-            self.bound_names(&mut |ident| {
-                let symbol_id = builder.declare_symbol(ident.span, &ident.name, includes, excludes);
-                ident.symbol_id.set(Some(symbol_id));
-            });
-        }
+
+        self.bound_names(&mut |ident| {
+            let symbol_id = builder.declare_symbol(ident.span, &ident.name, includes, excludes);
+            ident.symbol_id.set(Some(symbol_id));
+        });
     }
 }
 

crates/oxc_semantic/src/builder.rs

@@ -450,8 +450,11 @@ impl<'a> SemanticBuilder<'a> {
                     &self.nodes,
                 );
             }
-            AstKind::FormalParameters(params) => {
-                params.bind(self);
+            AstKind::RestElement(element) => {
+                element.bind(self);
+            }
+            AstKind::FormalParameter(param) => {
+                param.bind(self);
             }
             AstKind::CatchClause(clause) => {
                 clause.bind(self);