bootstrap-vue/src/utils/env.js

With more than 85 components, over 45 available plugins, several directives, and 1000+ icons, BootstrapVue provides one of the most comprehensive implementations of the Bootstrap v4 component and grid system available for Vue.js v2.6, complete with extens

/**
 * Utilities to get information about the current environment
 */

// --- Constants ---

export const hasWindowSupport = typeof window !== 'undefined'
export const hasDocumentSupport = typeof document !== 'undefined'
export const hasNavigatorSupport = typeof navigator !== 'undefined'
export const hasPromiseSupport = typeof Promise !== 'undefined'
/* istanbul ignore next: JSDOM always returns false */
export const hasMutationObserverSupport =
  typeof MutationObserver !== 'undefined' ||
  typeof WebKitMutationObserver !== 'undefined' ||
  typeof MozMutationObserver !== 'undefined'

export const isBrowser = hasWindowSupport && hasDocumentSupport && hasNavigatorSupport

// Browser type sniffing
export const userAgent = isBrowser ? window.navigator.userAgent.toLowerCase() : ''

export const isJSDOM = userAgent.indexOf('jsdom') > 0
export const isIE = /msie|trident/.test(userAgent)

// Determine if the browser supports the option passive for events
export const hasPassiveEventSupport = (() => {
  let passiveEventSupported = false
  if (isBrowser) {
    try {
      const options = {
        get passive() {
          // This function will be called when the browser
          // attempts to access the passive property.
          /* istanbul ignore next: will never be called in JSDOM */
          passiveEventSupported = true
        }
      }
      window.addEventListener('test', options, options)
      window.removeEventListener('test', options, options)
    } catch (err) {
      /* istanbul ignore next: will never be called in JSDOM */
      passiveEventSupported = false
    }
  }
  return passiveEventSupported
})()

export const hasTouchSupport =
  isBrowser && ('ontouchstart' in document.documentElement || navigator.maxTouchPoints > 0)

export const hasPointerEventSupport =
  isBrowser && Boolean(window.PointerEvent || window.MSPointerEvent)

/* istanbul ignore next: JSDOM only checks for 'IntersectionObserver' */
export const hasIntersectionObserverSupport =
  isBrowser &&
  'IntersectionObserver' in window &&
  'IntersectionObserverEntry' in window &&
  // Edge 15 and UC Browser lack support for `isIntersecting`
  // but we an use intersectionRatio > 0 instead
  // 'isIntersecting' in window.IntersectionObserverEntry.prototype &&
  'intersectionRatio' in window.IntersectionObserverEntry.prototype

// --- Getters ---

export const getEnv = (key, fallback = null) => {
  const env = typeof process !== 'undefined' && process ? process.env || {} : {}
  if (!key) {
    /* istanbul ignore next */
    return env
  }
  return env[key] || fallback
}

export const getNoWarn = () =>
  getEnv('BOOTSTRAP_VUE_NO_WARN') || getEnv('NODE_ENV') === 'production'