Apply Defaults - A simple utility to apply default values to any object.
at github.com▼2 up and 1 down, posted by
xat 2535 days ago. link parent 2 points ▲ ▼The way Object.assign is usually used is like this:
const opts = Object.assign({}, defaults, options);
It will fallback to the properties defined in defaults if they don't exist in options.
Nowadays you can also use destructering to achieve the same:
const opts = { ...defaults, ...options };
Yep, that's a great way to use Object.assign, but that doesn't really cover the variety of cases that prompted me to write this helper. For example, your code only works if options does not have a key for the default value, but not when it has a key with a null, undefined, or otherwise unacceptable value. const defaults = { name: '' }; const opts = { name: null }; Name would be set to null, which is a common case I try to avoid.If someone explicitly passes in "const opts = { name: null }" then I would argue that he wants name to be null and it should not be overwritten by what is defined in defaults. But I agree with you that there may be some (rare?) cases where some other behaviour is wanted.