'use strict'; var isProduction = process.env.NODE_ENV === 'production'; var prefix = 'Invariant failed'; function invariant(condition, message) { if (condition) { return; } if (isProduction) { throw new Error(prefix); } var provided = typeof message === 'function' ? message() : message; var value = provided ? prefix + ": " + provided : prefix; throw new Error(value); } module.exports = invariant;