debug.js

var config = require('../config')

/**
 * Enable debug utilities. The enableDebug() function and
 * all _.log() & _.warn() calls will be dropped in the
 * minified production build.
 */

enableDebug()

function enableDebug () {

  var hasConsole = typeof console !== 'undefined'
  
  /**
   * Log a message.
   *
   * @param {String} msg
   */

  exports.log = function (msg) {
    if (hasConsole && config.debug) {
      console.log('[Vue info]: ' + msg)
    }
  }

  /**
   * We've got a problem here.
   *
   * @param {String} msg
   */

  exports.warn = function (msg, e) {
    if (hasConsole && (!config.silent || config.debug)) {
      console.warn('[Vue warn]: ' + msg)
      /* istanbul ignore if */
      if (config.debug) {
        /* jshint debug: true */
        console.warn((e || new Error('Warning Stack Trace')).stack)
      }
    }
  }

  /**
   * Assert asset exists
   */

  exports.assertAsset = function (val, type, id) {
    /* istanbul ignore if */
    if (type === 'directive') {
      if (id === 'component') {
        exports.warn(
          'v-component has been deprecated in 0.12. ' +
          'Use custom element syntax instead.'
        )
        return
      }
      if (id === 'with') {
        exports.warn(
          'v-with has been deprecated in 0.12. ' +
          'Use props instead.'
        )
        return
      }
    }
    if (!val) {
      exports.warn('Failed to resolve ' + type + ': ' + id)
    }
  }
}