feat(traverse): add methods for creating Expression::Identifiers (#7301)

It's a common pattern in transformer to call `ctx.create_ident_reference()` and then convert to an `Expression` with `Expression::Identifier(ctx.ast.alloc(ident))`.

Add methods to do this in a single method call.

crates/oxc_transformer/src/common/helper_loader.rs

@@ -277,13 +277,8 @@ impl<'a> HelperLoaderStore<'a> {
         static HELPER_VAR: &str = "babelHelpers";
 
         let symbol_id = ctx.scopes().find_binding(ctx.current_scope_id(), HELPER_VAR);
-        let ident = ctx.create_ident_reference(
+        let object =
-            SPAN,
+            ctx.create_ident_expr(SPAN, Atom::from(HELPER_VAR), symbol_id, ReferenceFlags::Read);
-            Atom::from(HELPER_VAR),
-            symbol_id,
-            ReferenceFlags::Read,
-        );
-        let object = Expression::Identifier(ctx.alloc(ident));
         let property = ctx.ast.identifier_name(SPAN, Atom::from(helper.name()));
         Expression::from(ctx.ast.member_expression_static(SPAN, object, property, false))
     }

crates/oxc_transformer/src/common/module_imports.rs

@@ -226,14 +226,12 @@ impl<'a> ModuleImportsStore<'a> {
         require_symbol_id: Option<SymbolId>,
         ctx: &mut TraverseCtx<'a>,
     ) -> Statement<'a> {
-        let var_kind = VariableDeclarationKind::Var;
+        let callee = ctx.create_ident_expr(
-        let ident = ctx.create_ident_reference(
             SPAN,
             Atom::from("require"),
             require_symbol_id,
             ReferenceFlags::read(),
         );
-        let callee = Expression::Identifier(ctx.alloc(ident));
 
         let args = {
             let arg = Argument::from(ctx.ast.expression_string_literal(SPAN, source));
@@ -241,6 +239,7 @@ impl<'a> ModuleImportsStore<'a> {
         };
         let Some(Import::Default(local)) = names.into_iter().next() else { unreachable!() };
         let id = local.create_binding_pattern(ctx);
+        let var_kind = VariableDeclarationKind::Var;
         let decl = {
             let init = ctx.ast.expression_call(SPAN, callee, NONE, args, false);
             let decl = ctx.ast.variable_declarator(SPAN, var_kind, id, Some(init), false);

crates/oxc_transformer/src/es2016/exponentiation_operator.rs

@@ -164,18 +164,12 @@ impl<'a, 'ctx> ExponentiationOperator<'a, 'ctx> {
                 *reference.flags_mut() = ReferenceFlags::Write;
             }
 
-            Expression::Identifier(ctx.ast.alloc(ctx.create_bound_ident_reference(
+            ctx.create_bound_ident_expr(SPAN, ident.name.clone(), symbol_id, ReferenceFlags::Read)
-                SPAN,
-                ident.name.clone(),
-                symbol_id,
-                ReferenceFlags::Read,
-            )))
         } else {
             // Unbound reference. Could possibly trigger a getter so we need to only evaluate it once.
             // Assign to a temp var.
-            let reference = Expression::Identifier(ctx.ast.alloc(
+            let reference =
-                ctx.create_unbound_ident_reference(SPAN, ident.name.clone(), ReferenceFlags::Read),
+                ctx.create_unbound_ident_expr(SPAN, ident.name.clone(), ReferenceFlags::Read);
-            ));
             let binding = self.create_temp_var(reference, &mut temp_var_inits, ctx);
             binding.create_read_expression(ctx)
         };
@@ -495,14 +489,12 @@ impl<'a, 'ctx> ExponentiationOperator<'a, 'ctx> {
                 if let Some(symbol_id) = symbol_id {
                     // This variable is declared in scope so evaluating it multiple times can't trigger a getter.
                     // No need for a temp var.
-                    return Expression::Identifier(ctx.ast.alloc(
+                    return ctx.create_bound_ident_expr(
-                        ctx.create_bound_ident_reference(
                         SPAN,
                         ident.name.clone(),
                         symbol_id,
                         ReferenceFlags::Read,
-                        ),
+                    );
-                    ));
                 }
                 // Unbound reference. Could possibly trigger a getter so we need to only evaluate it once.
                 // Assign to a temp var.
@@ -548,13 +540,8 @@ impl<'a, 'ctx> ExponentiationOperator<'a, 'ctx> {
         ctx: &mut TraverseCtx<'a>,
     ) -> Expression<'a> {
         let math_symbol_id = ctx.scopes().find_binding(ctx.current_scope_id(), "Math");
-        let ident_math = ctx.create_ident_reference(
+        let object =
-            SPAN,
+            ctx.create_ident_expr(SPAN, Atom::from("Math"), math_symbol_id, ReferenceFlags::Read);
-            Atom::from("Math"),
-            math_symbol_id,
-            ReferenceFlags::Read,
-        );
-        let object = Expression::Identifier(ctx.alloc(ident_math));
         let property = ctx.ast.identifier_name(SPAN, "pow");
         let callee =
             Expression::from(ctx.ast.member_expression_static(SPAN, object, property, false));

crates/oxc_transformer/src/es2017/async_to_generator.rs

@@ -310,7 +310,7 @@ impl<'a, 'ctx> AsyncGeneratorExecutor<'a, 'ctx> {
                 let id = caller_function.id.as_ref().unwrap();
                 // If the function has an id, then we need to return the id.
                 // `function foo() { ... }` -> `function foo() {} return foo;`
-                let reference = ctx.create_bound_ident_reference(
+                let reference = ctx.create_bound_ident_expr(
                     SPAN,
                     id.name.clone(),
                     id.symbol_id(),
@@ -318,8 +318,7 @@ impl<'a, 'ctx> AsyncGeneratorExecutor<'a, 'ctx> {
                 );
                 let statement = Statement::FunctionDeclaration(caller_function);
                 statements.push(statement);
-                let argument = Some(Expression::Identifier(ctx.alloc(reference)));
+                statements.push(ctx.ast.statement_return(SPAN, Some(reference)));
-                statements.push(ctx.ast.statement_return(SPAN, argument));
             } else {
                 // If the function doesn't have an id, then we need to return the function itself.
                 // `function() { ... }` -> `return function() { ... };`
@@ -597,13 +596,12 @@ impl<'a, 'ctx> AsyncGeneratorExecutor<'a, 'ctx> {
         ctx: &mut TraverseCtx<'a>,
     ) -> Statement<'a> {
         let symbol_id = ctx.scopes().find_binding(ctx.current_scope_id(), "arguments");
-        let arguments_ident = ctx.create_ident_reference(
+        let arguments_ident = Argument::from(ctx.create_ident_expr(
             SPAN,
             Atom::from("arguments"),
             symbol_id,
             ReferenceFlags::Read,
-        );
+        ));
-        let arguments_ident = Argument::Identifier(ctx.alloc(arguments_ident));
 
         // (this, arguments)
         let mut arguments = ctx.ast.vec_with_capacity(2);

crates/oxc_transformer/src/es2018/object_rest_spread.rs

@@ -141,9 +141,8 @@ impl<'a, 'ctx> ObjectRestSpread<'a, 'ctx> {
     }
 
     fn object_assign(symbol_id: Option<SymbolId>, ctx: &mut TraverseCtx<'a>) -> Expression<'a> {
-        let ident =
+        let object =
-            ctx.create_ident_reference(SPAN, Atom::from("Object"), symbol_id, ReferenceFlags::Read);
+            ctx.create_ident_expr(SPAN, Atom::from("Object"), symbol_id, ReferenceFlags::Read);
-        let object = Expression::Identifier(ctx.alloc(ident));
         let property = ctx.ast.identifier_name(SPAN, Atom::from("assign"));
         Expression::from(ctx.ast.member_expression_static(SPAN, object, property, false))
     }

crates/oxc_transformer/src/jsx/refresh.rs

@@ -336,13 +336,12 @@ impl<'a, 'ctx> Traverse<'a> for ReactRefresh<'a, 'ctx> {
                             binding_name.as_str(),
                         )
                         .map(|symbol_id| {
-                            let ident = ctx.create_bound_ident_reference(
+                            let mut expr = ctx.create_bound_ident_expr(
                                 SPAN,
                                 binding_name,
                                 symbol_id,
                                 ReferenceFlags::Read,
                             );
-                            let mut expr = Expression::Identifier(ctx.alloc(ident));
 
                             if is_member_expression {
                                 // binding_name.hook_name
@@ -496,13 +495,12 @@ impl<'a, 'ctx> ReactRefresh<'a, 'ctx> {
         ctx: &mut TraverseCtx<'a>,
     ) -> Statement<'a> {
         let left = self.create_registration(id.name.clone(), ReferenceFlags::Write, ctx);
-        let right = ctx.create_bound_ident_reference(
+        let right = ctx.create_bound_ident_expr(
             SPAN,
             id.name.clone(),
             id.symbol_id(),
             ReferenceFlags::Read,
         );
-        let right = Expression::Identifier(ctx.alloc(right));
         let expr = ctx.ast.expression_assignment(SPAN, AssignmentOperator::Assign, left, right);
         ctx.ast.statement_expression(SPAN, expr)
     }

crates/oxc_transformer/src/regexp/mod.rs

@@ -180,13 +180,7 @@ impl<'a, 'ctx> Traverse<'a> for RegExp<'a, 'ctx> {
 
         let callee = {
             let symbol_id = ctx.scopes().find_binding(ctx.current_scope_id(), "RegExp");
-            let ident = ctx.create_ident_reference(
+            ctx.create_ident_expr(SPAN, Atom::from("RegExp"), symbol_id, ReferenceFlags::read())
-                SPAN,
-                Atom::from("RegExp"),
-                symbol_id,
-                ReferenceFlags::read(),
-            );
-            Expression::Identifier(ctx.alloc(ident))
         };
 
         let mut arguments = ctx.ast.vec_with_capacity(2);

crates/oxc_transformer/src/typescript/enum.rs

@@ -122,13 +122,12 @@ impl<'a> TypeScriptEnum<'a> {
         } else {
             // }(Foo || {});
             let op = LogicalOperator::Or;
-            let left = ctx.create_bound_ident_reference(
+            let left = ctx.create_bound_ident_expr(
                 decl.id.span,
                 enum_name.clone(),
                 var_symbol_id,
                 ReferenceFlags::Read,
             );
-            let left = Expression::Identifier(ctx.alloc(left));
             let right = ast.expression_object(SPAN, ast.vec(), None);
             let expression = ast.expression_logical(SPAN, left, op, right);
             ast.vec1(Argument::from(expression))

crates/oxc_traverse/src/context/mod.rs

@@ -445,6 +445,18 @@ impl<'a> TraverseCtx<'a> {
         self.ast.identifier_reference_with_reference_id(span, name, reference_id)
     }
 
+    /// Create an `Expression::Identifier` bound to a `SymbolId`.
+    pub fn create_bound_ident_expr(
+        &mut self,
+        span: Span,
+        name: Atom<'a>,
+        symbol_id: SymbolId,
+        flags: ReferenceFlags,
+    ) -> Expression<'a> {
+        let ident = self.create_bound_ident_reference(span, name, symbol_id, flags);
+        Expression::Identifier(self.ast.alloc(ident))
+    }
+
     /// Create an unbound reference.
     ///
     /// This is a shortcut for `ctx.scoping.create_unbound_reference`.
@@ -468,6 +480,17 @@ impl<'a> TraverseCtx<'a> {
         self.ast.identifier_reference_with_reference_id(span, name, reference_id)
     }
 
+    /// Create an unbound `Expression::Identifier`.
+    pub fn create_unbound_ident_expr(
+        &mut self,
+        span: Span,
+        name: Atom<'a>,
+        flags: ReferenceFlags,
+    ) -> Expression<'a> {
+        let ident = self.create_unbound_ident_reference(span, name, flags);
+        Expression::Identifier(self.ast.alloc(ident))
+    }
+
     /// Create a reference optionally bound to a `SymbolId`.
     ///
     /// If you know if there's a `SymbolId` or not, prefer `TraverseCtx::create_bound_reference`
@@ -502,6 +525,24 @@ impl<'a> TraverseCtx<'a> {
         }
     }
 
+    /// Create an `Expression::Identifier` optionally bound to a `SymbolId`.
+    ///
+    /// If you know if there's a `SymbolId` or not, prefer `TraverseCtx::create_bound_ident_expr`
+    /// or `TraverseCtx::create_unbound_ident_expr`.
+    pub fn create_ident_expr(
+        &mut self,
+        span: Span,
+        name: Atom<'a>,
+        symbol_id: Option<SymbolId>,
+        flags: ReferenceFlags,
+    ) -> Expression<'a> {
+        if let Some(symbol_id) = symbol_id {
+            self.create_bound_ident_expr(span, name, symbol_id, flags)
+        } else {
+            self.create_unbound_ident_expr(span, name, flags)
+        }
+    }
+
     /// Create reference in current scope, looking up binding for `name`,
     ///
     /// This is a shortcut for `ctx.scoping.create_reference_in_current_scope`.