==== tests/cases/compiler/assignmentCompatability30.ts (1 errors) ====
    module __test1__ {
        export interface interfaceWithPublicAndOptional<T,U> { one: T; two?: U; };  var obj4: interfaceWithPublicAndOptional<number,string> = { one: 1 };;
        export var __val__obj4 = obj4;
    }
    module __test2__ {
        export var aa:{one:number[];};;
        export var __val__aa = aa;
    }
    __test2__.__val__aa = __test1__.__val__obj4
    ~~~~~~~~~~~~~~~~~~~
!!! assignmentCompatability30.ts(9,1): error TS2012: Cannot convert '__test1__.interfaceWithPublicAndOptional<number, string>' to '{ one: number[]; }':
!!! 	Types of property 'one' of types '__test1__.interfaceWithPublicAndOptional<number, string>' and '{ one: number[]; }' are incompatible:
!!! 		Type 'Number' is missing property 'concat' from type 'number[]'.