Payload styles for ESLint and Prettier

Fixtures of ES values, for testing purposes

Determine whether the environment has the so-called "override mistake" - [[Set]]ing a property whose ancestor is nonwritable throws.

Does the environment have full property descriptor support? Handles IE 8's broken defineProperty/gOPD.

Command line tool for creating or updating a .npmignore file based on .gitignore.

the Istanbul command line interface

string representations of objects in node and the browser

tap-producing test harness for node and browsers