JsModule {
    bom_token: missing (optional),
    interpreter_token: missing (optional),
    directives: JsDirectiveList [],
    items: JsModuleItemList [
        JsVariableStatement {
            declaration: JsVariableDeclaration {
                await_token: missing (optional),
                kind: LET_KW@0..4 "let" [] [Whitespace(" ")],
                declarators: JsVariableDeclaratorList [
                    JsVariableDeclarator {
                        id: JsIdentifierBinding {
                            name_token: IDENT@4..6 "a" [] [Whitespace(" ")],
                        },
                        variable_annotation: missing (optional),
                        initializer: JsInitializerClause {
                            eq_token: EQ@6..8 "=" [] [Whitespace(" ")],
                            expression: JsArrowFunctionExpression {
                                async_token: missing (optional),
                                type_parameters: missing (optional),
                                parameters: JsParameters {
                                    l_paren_token: L_PAREN@8..9 "(" [] [],
                                    items: JsParameterList [
                                        JsBogusParameter {
                                            items: [
                                                THIS_KW@9..13 "this" [] [],
                                                TsTypeAnnotation {
                                                    colon_token: COLON@13..15 ":" [] [Whitespace(" ")],
                                                    ty: TsStringType {
                                                        string_token: STRING_KW@15..21 "string" [] [],
                                                    },
                                                },
                                            ],
                                        },
                                    ],
                                    r_paren_token: R_PAREN@21..23 ")" [] [Whitespace(" ")],
                                },
                                return_type_annotation: missing (optional),
                                fat_arrow_token: FAT_ARROW@23..26 "=>" [] [Whitespace(" ")],
                                body: JsFunctionBody {
                                    l_curly_token: L_CURLY@26..27 "{" [] [],
                                    directives: JsDirectiveList [],
                                    statements: JsStatementList [],
                                    r_curly_token: R_CURLY@27..28 "}" [] [],
                                },
                            },
                        },
                    },
                ],
            },
            semicolon_token: missing (optional),
        },
    ],
    eof_token: EOF@28..29 "" [Newline("\n")] [],
}

0: JS_MODULE@0..29
  0: (empty)
  1: (empty)
  2: JS_DIRECTIVE_LIST@0..0
  3: JS_MODULE_ITEM_LIST@0..28
    0: JS_VARIABLE_STATEMENT@0..28
      0: JS_VARIABLE_DECLARATION@0..28
        0: (empty)
        1: LET_KW@0..4 "let" [] [Whitespace(" ")]
        2: JS_VARIABLE_DECLARATOR_LIST@4..28
          0: JS_VARIABLE_DECLARATOR@4..28
            0: JS_IDENTIFIER_BINDING@4..6
              0: IDENT@4..6 "a" [] [Whitespace(" ")]
            1: (empty)
            2: JS_INITIALIZER_CLAUSE@6..28
              0: EQ@6..8 "=" [] [Whitespace(" ")]
              1: JS_ARROW_FUNCTION_EXPRESSION@8..28
                0: (empty)
                1: (empty)
                2: JS_PARAMETERS@8..23
                  0: L_PAREN@8..9 "(" [] []
                  1: JS_PARAMETER_LIST@9..21
                    0: JS_BOGUS_PARAMETER@9..21
                      0: THIS_KW@9..13 "this" [] []
                      1: TS_TYPE_ANNOTATION@13..21
                        0: COLON@13..15 ":" [] [Whitespace(" ")]
                        1: TS_STRING_TYPE@15..21
                          0: STRING_KW@15..21 "string" [] []
                  2: R_PAREN@21..23 ")" [] [Whitespace(" ")]
                3: (empty)
                4: FAT_ARROW@23..26 "=>" [] [Whitespace(" ")]
                5: JS_FUNCTION_BODY@26..28
                  0: L_CURLY@26..27 "{" [] []
                  1: JS_DIRECTIVE_LIST@27..27
                  2: JS_STATEMENT_LIST@27..27
                  3: R_CURLY@27..28 "}" [] []
      1: (empty)
  4: EOF@28..29 "" [Newline("\n")] []
--
ts_arrow_function_this_parameter.ts:1:10 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × An arrow function cannot have a 'this' parameter.
  
  > 1 │ let a = (this: string) => {}
      │          ^^^^^^^^^^^^
    2 │ 
  
--
let a = (this: string) => {}