core/packages/global.d.ts

// Global compile-time constants
declare var __DEV__: boolean
declare var __TEST__: boolean
declare var __BROWSER__: boolean
declare var __RUNTIME_COMPILE__: boolean
declare var __COMMIT__: string
declare var __VERSION__: string

// Feature flags
declare var __FEATURE_OPTIONS__: boolean
declare var __FEATURE_SUSPENSE__: boolean