tests/cases/compiler/indexSignatureWithoutTypeAnnotation1.ts(2,3): error TS1021: An index signature must have a type annotation.


==== tests/cases/compiler/indexSignatureWithoutTypeAnnotation1.ts (1 errors) ====
    class C {
      [a: number];
      ~~~~~~~~~~~~
!!! error TS1021: An index signature must have a type annotation.
    }