Ruby's keyword args work a little differently than similar implementations (selectors in Objective C, for instance). The value on the right-hand side of the colon is the default, not the local name.

hash :with_defaults, default: {} do boolean :likes_cookies, default: true end

const debounceFunc = debounce(1000, false, (num) => {    console.log('num:', num);}); // Can also be used like this, because atBegin is false by defaultconst debounceFunc = debounce(1000, (num) => {    console.log('num:', num);});

However, in function components there really isn't much need for this pattern since you can just use JS default arguments

For a long time I considered default values to be a "pure evil" thing, something that "cloaks the catastrophe" and results in a very hard do find bugs.