tests/cases/conformance/parser/ecmascript5/Symbols/parserES5SymbolIndexer1.ts(2,9): error TS1188: 'symbol' indexers are only available when targeting ECMAScript 6 and higher.
==== tests/cases/conformance/parser/ecmascript5/Symbols/parserES5SymbolIndexer1.ts (1 errors) ====
interface I {
[s: symbol]: string;
~~~~~~
!!! error TS1188: 'symbol' indexers are only available when targeting ECMAScript 6 and higher.
}