{
  "compilerOptions": {
    "emitDecoratorMetadata": true,
    "experimentalDecorators": true,
    "target": "es5",
    "module": "commonjs",
    "moduleResolution": "node",
    "removeComments": true,
    "sourceMap": true,
    "declaration": true,
    "outDir": "dist",
    "lib": [
      "es2015",
      "dom"
    ]
  },
  "angularCompilerOptions": {
    "genDir": "aot",
    "skipMetadataEmit": false
  },
  "compileOnSave": false,
  "buildOnSave": false,
  "files": [
    "src/index.ts"
  ],
  "exclude": [
    "node_modules"
  ]
}
{
  "compilerOptions": {
    "emitDecoratorMetadata": true,
    "strictNullChecks": true,
    "experimentalDecorators": true,
    "target": "es5",
    "module": "commonjs",
    "moduleResolution": "node",
    "removeComments": true,
    "sourceMap": true,
    "declaration": true,
    "outDir": "dist",
    "lib": [
      "es2015",
      "dom"
    ]
  },
  "angularCompilerOptions": {
    "genDir": "aot",
    "skipMetadataEmit": false
  },
  "compileOnSave": false,
  "buildOnSave": false,
  "files": [
    "src/index.ts"
  ],
  "exclude": [
    "node_modules"
  ]
}

Add strictNullChecks. This does code more robust
Add strictNullChecks. This does code more robust
