/foo/tsconfig.json(2,26): error TS5069: Option 'declarationDir' cannot be specified without specifying option 'declaration' or option 'composite'.


==== /foo/tsconfig.json (1 errors) ====
    {
        "compilerOptions": { "declarationDir": "out" }
                             ~~~~~~~~~~~~~~~~
!!! error TS5069: Option 'declarationDir' cannot be specified without specifying option 'declaration' or option 'composite'.
    }
    
==== /foo/test.ts (0 errors) ====
    interface Foo {
        x: number;
    }
    export default Foo;
    