bootstrap-vue/src/utils/env.js

BootstrapVue, with over 40 plugins and more than 80 custom components, custom directives, and over 300 icons, provides one of the most comprehensive implementations of Bootstrap v4 components and grid system for Vue.js. With extensive and automated WAI-AR

/**
 * 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'
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)

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')