tests/cases/conformance/parser/ecmascript5/IndexSignatures/parserIndexSignature6.ts(2,4): error TS1023: An index signature parameter type must be 'string' or 'number'.
==== tests/cases/conformance/parser/ecmascript5/IndexSignatures/parserIndexSignature6.ts (1 errors) ====
interface I {
[a:boolean]
~
!!! error TS1023: An index signature parameter type must be 'string' or 'number'.
}