JsModule {
    interpreter_token: missing (optional),
    directives: JsDirectiveList [],
    items: JsModuleItemList [
        JsBogusStatement {
            items: [
                JsBogus {
                    items: [
                        LET_KW@0..4 "let" [] [Whitespace(" ")],
                        JsBogus {
                            items: [
                                JsBogus {
                                    items: [
                                        JsIdentifierBinding {
                                            name_token: IDENT@4..5 "a" [] [],
                                        },
                                        JsBogus {
                                            items: [
                                                BANG@5..6 "!" [] [],
                                                TsTypeAnnotation {
                                                    colon_token: COLON@6..8 ":" [] [Whitespace(" ")],
                                                    ty: TsStringType {
                                                        string_token: STRING_KW@8..15 "string" [] [Whitespace(" ")],
                                                    },
                                                },
                                            ],
                                        },
                                        JsInitializerClause {
                                            eq_token: EQ@15..17 "=" [] [Whitespace(" ")],
                                            expression: JsStringLiteralExpression {
                                                value_token: JS_STRING_LITERAL@17..23 "\"test\"" [] [],
                                            },
                                        },
                                    ],
                                },
                            ],
                        },
                    ],
                },
                SEMICOLON@23..24 ";" [] [],
            ],
        },
    ],
    eof_token: EOF@24..25 "" [Newline("\n")] [],
}

0: JS_MODULE@0..25
  0: (empty)
  1: JS_DIRECTIVE_LIST@0..0
  2: JS_MODULE_ITEM_LIST@0..24
    0: JS_BOGUS_STATEMENT@0..24
      0: JS_BOGUS@0..23
        0: LET_KW@0..4 "let" [] [Whitespace(" ")]
        1: JS_BOGUS@4..23
          0: JS_BOGUS@4..23
            0: JS_IDENTIFIER_BINDING@4..5
              0: IDENT@4..5 "a" [] []
            1: JS_BOGUS@5..15
              0: BANG@5..6 "!" [] []
              1: TS_TYPE_ANNOTATION@6..15
                0: COLON@6..8 ":" [] [Whitespace(" ")]
                1: TS_STRING_TYPE@8..15
                  0: STRING_KW@8..15 "string" [] [Whitespace(" ")]
            2: JS_INITIALIZER_CLAUSE@15..23
              0: EQ@15..17 "=" [] [Whitespace(" ")]
              1: JS_STRING_LITERAL_EXPRESSION@17..23
                0: JS_STRING_LITERAL@17..23 "\"test\"" [] []
      1: SEMICOLON@23..24 ";" [] []
  3: EOF@24..25 "" [Newline("\n")] []
--
ts_definite_variable_with_initializer.js:1:6 parse ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  × definite assertion assignments are a TypeScript only feature. Convert your file to a TypeScript file or remove the syntax.
  
  > 1 │ let a!: string = "test";
      │      ^^^^^^^^^
    2 │ 
  
  i TypeScript only syntax
  
--
let a!: string = "test";