JsModule {
    bom_token: missing (optional),
    interpreter_token: missing (optional),
    directives: JsDirectiveList [],
    items: JsModuleItemList [
        JsClassDeclaration {
            decorators: JsDecoratorList [],
            abstract_token: missing (optional),
            class_token: CLASS_KW@0..6 "class" [] [Whitespace(" ")],
            id: JsIdentifierBinding {
                name_token: IDENT@6..8 "B" [] [Whitespace(" ")],
            },
            type_parameters: missing (optional),
            extends_clause: missing (optional),
            implements_clause: missing (optional),
            l_curly_token: L_CURLY@8..10 "{" [] [Whitespace(" ")],
            members: JsClassMemberList [
                JsConstructorClassMember {
                    modifiers: JsConstructorModifierList [],
                    name: JsLiteralMemberName {
                        value: IDENT@10..21 "constructor" [] [],
                    },
                    parameters: JsConstructorParameters {
                        l_paren_token: L_PAREN@21..22 "(" [] [],
                        parameters: JsConstructorParameterList [
                            JsBogusParameter {
                                items: [
                                    JsDecoratorList [],
                                    TsPropertyParameterModifierList [
                                        TsReadonlyModifier {
                                            modifier_token: READONLY_KW@22..31 "readonly" [] [Whitespace(" ")],
                                        },
                                    ],
                                    JsFormalParameter {
                                        decorators: JsDecoratorList [],
                                        binding: JsIdentifierBinding {
                                            name_token: IDENT@31..32 "b" [] [],
                                        },
                                        question_mark_token: missing (optional),
                                        type_annotation: missing (optional),
                                        initializer: missing (optional),
                                    },
                                ],
                            },
                        ],
                        r_paren_token: R_PAREN@32..34 ")" [] [Whitespace(" ")],
                    },
                    body: JsFunctionBody {
                        l_curly_token: L_CURLY@34..35 "{" [] [],
                        directives: JsDirectiveList [],
                        statements: JsStatementList [],
                        r_curly_token: R_CURLY@35..37 "}" [] [Whitespace(" ")],
                    },
                },
            ],
            r_curly_token: R_CURLY@37..38 "}" [] [],
        },
    ],
    eof_token: EOF@38..39 "" [Newline("\n")] [],
}

0: JS_MODULE@0..39
  0: (empty)
  1: (empty)
  2: JS_DIRECTIVE_LIST@0..0
  3: JS_MODULE_ITEM_LIST@0..38
    0: JS_CLASS_DECLARATION@0..38
      0: JS_DECORATOR_LIST@0..0
      1: (empty)
      2: CLASS_KW@0..6 "class" [] [Whitespace(" ")]
      3: JS_IDENTIFIER_BINDING@6..8
        0: IDENT@6..8 "B" [] [Whitespace(" ")]
      4: (empty)
      5: (empty)
      6: (empty)
      7: L_CURLY@8..10 "{" [] [Whitespace(" ")]
      8: JS_CLASS_MEMBER_LIST@10..37
        0: JS_CONSTRUCTOR_CLASS_MEMBER@10..37
          0: JS_CONSTRUCTOR_MODIFIER_LIST@10..10
          1: JS_LITERAL_MEMBER_NAME@10..21
            0: IDENT@10..21 "constructor" [] []
          2: JS_CONSTRUCTOR_PARAMETERS@21..34
            0: L_PAREN@21..22 "(" [] []
            1: JS_CONSTRUCTOR_PARAMETER_LIST@22..32
              0: JS_BOGUS_PARAMETER@22..32
                0: JS_DECORATOR_LIST@22..22
                1: TS_PROPERTY_PARAMETER_MODIFIER_LIST@22..31
                  0: TS_READONLY_MODIFIER@22..31
                    0: READONLY_KW@22..31 "readonly" [] [Whitespace(" ")]
                2: JS_FORMAL_PARAMETER@31..32
                  0: JS_DECORATOR_LIST@31..31
                  1: JS_IDENTIFIER_BINDING@31..32
                    0: IDENT@31..32 "b" [] []
                  2: (empty)
                  3: (empty)
                  4: (empty)
            2: R_PAREN@32..34 ")" [] [Whitespace(" ")]
          3: JS_FUNCTION_BODY@34..37
            0: L_CURLY@34..35 "{" [] []
            1: JS_DIRECTIVE_LIST@35..35
            2: JS_STATEMENT_LIST@35..35
            3: R_CURLY@35..37 "}" [] [Whitespace(" ")]
      9: R_CURLY@37..38 "}" [] []
  4: EOF@38..39 "" [Newline("\n")] []
--
class_constructor_parameter_readonly.js:1:23 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × 'readonly' modifier can only be used in TypeScript files
  
  > 1 │ class B { constructor(readonly b) {} }
      │                       ^^^^^^^^
    2 │ 
  
--
class B { constructor(readonly b) {} }