maaybe

maaybe introduces a new way to think about values.

You may need maaybe or maybe not. But since you maybe need it, maybe just install it. Maybe you don't need maaybe, but having maaybe installed may make your life merrier.

What is maaybe?

maaybe is a library that introduces a new way to think about values. It introduces the value maybe. If you know that the value will exist in the future, but it doesn't exist initially, you can use maybe to represent that value.

For example, if you have isLoggedIn, you can give it the value maybe when the data is still loading, and then update it to true or false when the data is available. This allows you to handle the case where the data is not available yet, without having to write a lot of conditional logic.

TLDR maybe is just an alias for undefined.

Development

pnpm run compile # will compile to both cjs and mjs
pnpm run test    # will run tests

Usage

pnpm install maaybe

// your main.ts or index.ts entry file
import 'maaybe';

// any file in the project
function SecureApp() {
  const [isLoggedIn, setIsLoggedIn] = useState<maybe>(maybe);

  useEffect(() => {
    getUser().then((user) => {
      setIsLoggedIn(!!user);
    });
  }, []);

  if (isLoggedIn === maybe) {
    return <Loading />;
  }

  if (isLoggedIn === false) {
    return <Login />;
  }

  return <Home />;
}


// any file in the project
function ShowUser() {
  const [user, setUser] = useState<maybe<User>>(maybe);

  useEffect(() => {
    getUser().then((user) => {
      setUser(user);
    });
  }, []);

  if (isMaybe(user)) {
    return <Loading />;
  }

  // This also works
  // if (user === maybe) {
  //   return <Loading />;
  // }

  if (user === null) {
    return <Login />;
  }

  // Fully type safe
  return <UserProfile user={user} />;
}

API

The value maybe

const explicitlyMaybe = maybe;

// The following are all true
maybe === maybe;
maybe !== null;
maybe !== 0;
maybe !== '';
maybe !== {};
maybe !== [];
maybe !== (() => void null);
maybe !== true;
maybe !== false;
isMaybe(maybe);

The type maybe

const thisMaybeMaybe: maybe;

// The following statements can be true but only one at a time
thisMaybeMaybe === maybe;
thisMaybeMaybe === true;
thisMaybeMaybe === false;

const thisMaybeMaybe: maybe<User>;

// The following statements can be true but only one at a time
thisMaybeMaybe === maybe;
thisMaybeMaybe === null;
thisMaybeMaybe instanceof User;