Alternative to TypeScript

Question

I've seen and heard some issues with adding TypeScript to an existing project. But I also know, it can help find bugs, because of the wrong types getting used. I don't want to use TypeScript. Is there any other way to achieve type safety?

Answer 1

What do you not like about TypeScript? It requires a fair amount of knowledge and getting used to, but it arguably makes code much more 'correct'.

See flow.org for an alternative to TypeScript. But TS has far greater adoption and industry backing. Most jobs nowadays require TS experience.

Answer 2

A great alternative to TypeScript is JSDOC. JSDoc is an open source API documentation generator for Javascript. You can also use typeof to check for primitive types or you can use duck typing. Duck typing is a programming style that uses the "duck test" to determine if an object can be used for a specific purpose. The test states, "If it walks like a duck and it quacks like a duck, then it must be a duck".

Here are some example Javascript functions that can help you get started with type safety.

/**

* @param {String} error

* @param {String} doThrow

* @returns {true|null}

* @throws {TypeError}

*/

function doThrowError(error, doThrow) {

if (doThrow === 'DO_THROW') {

console.warn(error);

return null;

} else {

throw new TypeError(error);

}

}

/**

* @param {*} type

* @param {string} doThrow

* @returns {true|null}

* @throws {TypeError}

*/

function confirmType(type, doThrow) {

if (type && typeof type[0] !== type[1]) {

const error = `${type[0]} must be a ${type[1]}.`;

return doThrowError(error, doThrow);

}

return true;

}

/**

* @param {string} type

* @param {string} doThrow

* @returns {true|null}

* @throws {TypeError}

*/

function confirmTypeString(type, doThrow) {

return confirmType([type, 'string'], doThrow);

}

/**

* @param {Function} type

* @param {string} doThrow

* @returns {true|null}

* @throws {TypeError}

*/

function confirmTypeFunction(type, doThrow) {

return confirmType([type, 'function'], doThrow);

}

/**

* @param {Number} type

* @param {string} doThrow

* @returns {true|null}

* @throws {TypeError}

*/

function confirmTypeNumber(type, doThrow) {

return confirmType([type, 'number'], doThrow);

}