function load(
  options: LoadOptions = {
    path: 'application.env', // Path to a file
    failSilently: false, // Returns/appends an empty object on error instead of throwing it.
    validator: ObjectValidator<Env> // Environment validator (read bellow)
  }): Promise<ApplicationEnv.Env> {}

interface Env {
  propOne: string;
  nonStringProperty: number;
  optionalProperty: string;
  criticalProperty: string;
}

const validator: ObjectValidator<Env> = {
  propOne: {
    errorMessage: "No default provided, throwing an error",
  },
  nonStringProperty: {
    default: 420,
    converter: (value) => Number(value)
  },
  optionalProperty: {
    default: "DEFAULT VALUE",
  },
  criticalProperty: {
    critical: true,
    errorMessage: "The application cannot function without this property. Terminating...",
  },
};

load({validator})

declare global {
  namespace ApplicationEnv {
    interface Env {
      MY_PROP_ONE?: string;
      ANOTHER_REQUIRED_PROP: string;
      ANOTHER_OPTIONAL_PROP: string;
      NODE_ENV?: string;
    }
  }
}

import ApplicationEnvProvider, { useApplicationEnv } from 'application.env/react';

const App: FC = (): JSX.Element => {
  return (
    <ApplicationEnvProvider path="/application.env">
      <Child>
    </ApplicationEnvProvider>
  );
};

const Child: FC = () : JSX.Element => {
  const envVars = useApplicationEnv();

  return (<h1>{envVars.MY_PROP_ONE}</h1>)
}

export default App;