no-new-wrappers

Disallow new String(), new Number() and new Boolean()

With new, String, Number and Boolean return an object that wraps the value, not the value itself. typeof new String("a") is "object", new Number(1) === 1 is false, and new Boolean(false) is truthy, so the if below always runs.

Without new, the same functions convert a value and return a plain string, number or boolean.

With an oxlint config, --fix rewrites new String("Ada") to "Ada" and new Number(input) to Number(input).

Configure#

Off by default. To turn it on:

bunfig.toml
[lint.rules]
"no-new-wrappers" = "error" # or "warn"

Examples#

example.js1 problem
const enabled = new Boolean(false);

if (enabled) {
  start();
}
example.js2 problems
const name = new String("Ada");
const port = new Number(input);
example.jsNo problems
const enabled = false;
const name = "Ada";
const port = Number(input);