value-or-promise

Handling values or promises uniformly

This feature allows you to handle both direct values and promises using the same API, which simplifies the code when the nature of the value is not known in advance or can vary.

const { ValueOrPromise } = require('value-or-promise');

function getValueOrPromise(value) {
  return new ValueOrPromise(() => value)
    .then(v => v)
    .resolve();
}

// Usage with a direct value
getValueOrPromise(42).then(console.log); // 42

// Usage with a promise
getValueOrPromise(Promise.resolve(42)).then(console.log); // 42

Chaining operations

This feature allows chaining multiple operations on a value or promise, with each operation being applied as the previous one resolves. It's similar to promise chaining but works with non-promise values as well.

const { ValueOrPromise } = require('value-or-promise');

function chainOperations(value) {
  return new ValueOrPromise(() => value)
    .then(v => v * 2)
    .then(v => v + 1)
    .resolve();
}

// Usage with a direct value
chainOperations(10).then(console.log); // 21

// Usage with a promise
chainOperations(Promise.resolve(10)).then(console.log); // 21

Error handling

This feature provides a way to handle errors that may occur during the processing of a value or promise, similar to how errors are caught in promise chains.

const { ValueOrPromise } = require('value-or-promise');

function handleErrors(value) {
  return new ValueOrPromise(() => value)
    .then(v => {
      if (v < 0) throw new Error('Negative value');
      return v;
    })
    .catch(error => 'Error: ' + error.message)
    .resolve();
}

// Usage with a direct value
handleErrors(-10).then(console.log); // Error: Negative value

// Usage with a promise
handleErrors(Promise.resolve(-10)).then(console.log); // Error: Negative value