tsconfig.json

{
    "compilerOptions": {
        "target": "es5",
        "alwaysStrict": true,
        "noImplicitAny": true,
        "noImplicitThis": true,
        "sourceMap": false,
        "noUnusedLocals": true,
        "strictNullChecks": true,
        //"downlevelIteration": true,
        "lib": [ "es6", "dom" ],
        "outDir": "build/js/src"
    },
    "include": [ "src/**/*" ]
}