moduleReopenedTypeOtherBlock.ts(6,32): error TS2322: Type 'null' is not assignable to type 'I'.


==== moduleReopenedTypeOtherBlock.ts (1 errors) ====
    namespace M {
        export class C1 { }
        export interface I { n: number; }
    }
    namespace M {
        export class C2 { f(): I { return null; } }
                                   ~~~~~~
!!! error TS2322: Type 'null' is not assignable to type 'I'.
    }
    