JsModule {
    bom_token: missing (optional),
    interpreter_token: missing (optional),
    directives: JsDirectiveList [],
    items: JsModuleItemList [
        JsForStatement {
            for_token: FOR_KW@0..4 "for" [] [Whitespace(" ")],
            l_paren_token: L_PAREN@4..5 "(" [] [],
            initializer: JsArrowFunctionExpression {
                async_token: missing (optional),
                type_parameters: missing (optional),
                parameters: JsParameters {
                    l_paren_token: L_PAREN@5..6 "(" [] [],
                    items: JsParameterList [
                        JsBogusParameter {
                            items: [
                                JsDecoratorList [],
                                DOT3@6..9 "..." [] [],
                                JsIdentifierBinding {
                                    name_token: IDENT@9..11 "a" [] [Whitespace(" ")],
                                },
                                JsInitializerClause {
                                    eq_token: EQ@11..13 "=" [] [Whitespace(" ")],
                                    expression: JsInExpression {
                                        property: JsStringLiteralExpression {
                                            value_token: JS_STRING_LITERAL@13..17 "\"b\"" [] [Whitespace(" ")],
                                        },
                                        in_token: IN_KW@17..20 "in" [] [Whitespace(" ")],
                                        object: JsObjectExpression {
                                            l_curly_token: L_CURLY@20..21 "{" [] [],
                                            members: JsObjectMemberList [],
                                            r_curly_token: R_CURLY@21..22 "}" [] [],
                                        },
                                    },
                                },
                            ],
                        },
                    ],
                    r_paren_token: R_PAREN@22..24 ")" [] [Whitespace(" ")],
                },
                return_type_annotation: missing (optional),
                fat_arrow_token: FAT_ARROW@24..27 "=>" [] [Whitespace(" ")],
                body: JsFunctionBody {
                    l_curly_token: L_CURLY@27..28 "{" [] [],
                    directives: JsDirectiveList [],
                    statements: JsStatementList [],
                    r_curly_token: R_CURLY@28..29 "}" [] [],
                },
            },
            first_semi_token: SEMICOLON@29..30 ";" [] [],
            test: missing (optional),
            second_semi_token: SEMICOLON@30..31 ";" [] [],
            update: missing (optional),
            r_paren_token: R_PAREN@31..33 ")" [] [Whitespace(" ")],
            body: JsBlockStatement {
                l_curly_token: L_CURLY@33..34 "{" [] [],
                statements: JsStatementList [],
                r_curly_token: R_CURLY@34..35 "}" [] [],
            },
        },
    ],
    eof_token: EOF@35..36 "" [Newline("\n")] [],
}

0: JS_MODULE@0..36
  0: (empty)
  1: (empty)
  2: JS_DIRECTIVE_LIST@0..0
  3: JS_MODULE_ITEM_LIST@0..35
    0: JS_FOR_STATEMENT@0..35
      0: FOR_KW@0..4 "for" [] [Whitespace(" ")]
      1: L_PAREN@4..5 "(" [] []
      2: JS_ARROW_FUNCTION_EXPRESSION@5..29
        0: (empty)
        1: (empty)
        2: JS_PARAMETERS@5..24
          0: L_PAREN@5..6 "(" [] []
          1: JS_PARAMETER_LIST@6..22
            0: JS_BOGUS_PARAMETER@6..22
              0: JS_DECORATOR_LIST@6..6
              1: DOT3@6..9 "..." [] []
              2: JS_IDENTIFIER_BINDING@9..11
                0: IDENT@9..11 "a" [] [Whitespace(" ")]
              3: JS_INITIALIZER_CLAUSE@11..22
                0: EQ@11..13 "=" [] [Whitespace(" ")]
                1: JS_IN_EXPRESSION@13..22
                  0: JS_STRING_LITERAL_EXPRESSION@13..17
                    0: JS_STRING_LITERAL@13..17 "\"b\"" [] [Whitespace(" ")]
                  1: IN_KW@17..20 "in" [] [Whitespace(" ")]
                  2: JS_OBJECT_EXPRESSION@20..22
                    0: L_CURLY@20..21 "{" [] []
                    1: JS_OBJECT_MEMBER_LIST@21..21
                    2: R_CURLY@21..22 "}" [] []
          2: R_PAREN@22..24 ")" [] [Whitespace(" ")]
        3: (empty)
        4: FAT_ARROW@24..27 "=>" [] [Whitespace(" ")]
        5: JS_FUNCTION_BODY@27..29
          0: L_CURLY@27..28 "{" [] []
          1: JS_DIRECTIVE_LIST@28..28
          2: JS_STATEMENT_LIST@28..28
          3: R_CURLY@28..29 "}" [] []
      3: SEMICOLON@29..30 ";" [] []
      4: (empty)
      5: SEMICOLON@30..31 ";" [] []
      6: (empty)
      7: R_PAREN@31..33 ")" [] [Whitespace(" ")]
      8: JS_BLOCK_STATEMENT@33..35
        0: L_CURLY@33..34 "{" [] []
        1: JS_STATEMENT_LIST@34..34
        2: R_CURLY@34..35 "}" [] []
  4: EOF@35..36 "" [Newline("\n")] []
--
arrow_rest_in_expr_in_initializer.js:1:12 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × rest elements may not have default initializers
  
  > 1 │ for ((...a = "b" in {}) => {};;) {}
      │            ^^^^^^^^^^^
    2 │ 
  
--
for ((...a = "b" in {}) => {};;) {}