/** * Copyright (c) 2014-present, Facebook, Inc. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. */ 'use strict'; /** * Similar to invariant but only logs a warning if the condition is not met. * This can be used to log issues in development environments in critical * paths. Removing the logging code for production environments will keep the * same logic and follow the same code paths. */ var __DEV__ = process.env.NODE_ENV !== 'production'; var warning = function() {}; if (__DEV__) { var printWarning = function printWarning(format, args) { var len = arguments.length; args = new Array(len > 1 ? len - 1 : 0); for (var key = 1; key < len; key++) { args[key - 1] = arguments[key]; } var argIndex = 0; var message = 'Warning: ' + format.replace(/%s/g, function() { return args[argIndex++]; }); if (typeof console !== 'undefined') { console.error(message); } try { // --- Welcome to debugging React --- // This error was thrown as a convenience so that you can use this stack // to find the callsite that caused this warning to fire. throw new Error(message); } catch (x) {} } warning = function(condition, format, args) { var len = arguments.length; args = new Array(len > 2 ? len - 2 : 0); for (var key = 2; key < len; key++) { args[key - 2] = arguments[key]; } if (format === undefined) { throw new Error( '`warning(condition, format, ...args)` requires a warning ' + 'message argument' ); } if (!condition) { printWarning.apply(null, [format].concat(args)); } }; } module.exports = warning;