==== tests/cases/compiler/assignmentCompatability19.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 obj = {two: [1]};
        export var __val__obj = obj;
    }
    __test2__.__val__obj = __test1__.__val__obj4
    ~~~~~~~~~~~~~~~~~~~~
!!! Type 'interfaceWithPublicAndOptional<number, string>' is not assignable to type '{ two: number[]; }':
!!!   Types of property 'two' are incompatible:
!!!     Type 'string' is not assignable to type 'number[]':
!!!       Types of property 'concat' are incompatible:
!!!         Type '(...strings: string[]) => string' is not assignable to type '{ <U extends number[]>(...items: U[]): number[]; (...items: number[]): number[]; }':
!!!           Types of parameters 'strings' and 'items' are incompatible:
!!!             Type 'string' is not assignable to type 'number'.