get value of an environment variable; throw if undefined or empty string

Retry a function until or while it passes an assertion

If given value is not an object, returns an object with one entry.

mongoose validation to ensure referenced object id exists

Prevents a string or an array from ending with specified value.

Prevents a string or an array from starting with specified value.

Ensures that a string or an array ends with specified value.

Ensures that a string or an array starts with specified value.

Utilities to validate/ensure emails against a whitelist. 👮‍♂️📧

Transform JS function code, function bodies, modules, or files into valid functions using AST transform and VM wizardry.

Provide simple checks of method parameters on NodeJS

How To Make Sure jQuery Is Loaded And Only Once