1declare const global: any; 2 3// In standard node environments there is no DOM API 4export const isDOMAvailable = false; 5export const canUseEventListeners = false; 6export const canUseViewport = false; 7 8export let isAsyncDebugging: boolean = false; 9 10if (__DEV__) { 11 // These native globals are injected by native React runtimes and not standard browsers 12 // we can use them to determine if the JS is being executed in Chrome. 13 isAsyncDebugging = 14 !global.nativeExtensions && !global.nativeCallSyncHook && !global.RN$Bridgeless; 15} 16