fluorine-lib/es/util/warn.js

Reactive state and side effect management for React using a single stream of actions

var __DEV__ = process.env.NODE_ENV !== 'production';

export default function warn(msg) {
  var hasWarned = false;

  return function () {
    if (__DEV__ && !hasWarned && console.warn) {
      console.warn(msg);
      hasWarned = true;
    }
  };
}