feat(rome_js_parser): EcmaScript @decorators #4252

crates/rome_js_parser/src/syntax/class.rs

@@ -2156,7 +2156,7 @@ impl ClassMemberModifiers {
                     | JS_SETTER_CLASS_MEMBER
             )
         {
-            // test_err ts decorator_parameters
+            // test ts decorator_parameters_constructor
             // class Foo {
             //    constructor(@dec a: string) {}
             // }
@@ -2642,3 +2642,29 @@ fn parse_decorator(p: &mut JsParser) -> ParsedSyntax {
 
     Present(m.complete(p, JS_DECORATOR))
 }
+
+/// Skips over any TypeScript decorator syntax.
+pub(crate) fn skip_ts_decorators(p: &mut JsParser) {
+    if !p.at(T![@]) {
+        return;
+    }
+
+    p.parse_as_skipped_trivia_tokens(|p| {
+        while p.at(T![@]) {
+            parse_decorator_bogus(p).ok();
+        }
+    });
+}
+
+fn parse_decorator_bogus(p: &mut JsParser) -> ParsedSyntax {
+    if p.at(T![@]) {
+        let m = p.start();
+        p.bump(T![@]);
+        parse_lhs_expr(p, ExpressionContext::default().and_in_decorator(true))
+            .or_add_diagnostic(p, expected_expression);
+
+        Present(m.complete(p, JS_BOGUS))
+    } else {
+        Absent
+    }
+}

crates/rome_js_parser/src/syntax/function.rs

@@ -4,14 +4,12 @@ use crate::state::{EnterFunction, EnterParameters, SignatureFlags};
 use crate::syntax::binding::{
     is_at_identifier_binding, is_nth_at_identifier_binding, parse_binding, parse_binding_pattern,
 };
-use crate::syntax::class::{parse_decorators, parse_initializer_clause};
+use crate::syntax::class::{parse_initializer_clause, skip_ts_decorators};
 use crate::syntax::expr::{
     is_nth_at_identifier, parse_assignment_expression_or_higher, ExpressionContext,
 };
 use crate::syntax::js_parse_error;
-use crate::syntax::js_parse_error::{
-    decorators_not_allowed, expected_binding, expected_parameter, expected_parameters,
-};
+use crate::syntax::js_parse_error::{expected_binding, expected_parameter, expected_parameters};
 use crate::syntax::stmt::{is_semi, parse_block_impl, semi, StatementContext};
 use crate::syntax::typescript::ts_parse_error::ts_only_syntax_error;
 use crate::syntax::typescript::{
@@ -1026,14 +1024,13 @@ pub(crate) fn parse_formal_parameter(
     parameter_context: ParameterContext,
     expression_context: ExpressionContext,
 ) -> ParsedSyntax {
-    // test_err ts ts_formal_parameter_decorator
+    // test ts ts_formal_parameter_decorator
     // function a(@dec x) {}
     // class Foo {
     //    constructor(@dec x) {}
     //    method(@dec x) {}
     // }
-    let decorator_list = parse_decorators(p);
-    decorator_list.add_diagnostic_if_present(p, decorators_not_allowed);
+    skip_ts_decorators(p);
 
     parse_binding_pattern(p, expression_context).map(|binding| {
         let binding_kind = binding.kind(p);