core/packages/global.d.ts

// Global compile-time constants
declare var __DEV__: boolean
declare var __TEST__: boolean
declare var __BROWSER__: boolean
declare var __GLOBAL__: boolean
declare var __ESM_BUNDLER__: boolean
declare var __ESM_BROWSER__: boolean
declare var __NODE_JS__: boolean
declare var __COMMIT__: string
declare var __VERSION__: string

// Feature flags
declare var __FEATURE_OPTIONS_API__: boolean
declare var __FEATURE_PROD_DEVTOOLS__: boolean
declare var __FEATURE_SUSPENSE__: boolean

// for tests
declare namespace jest {
  interface Matchers<R, T> {
    toHaveBeenWarned(): R
    toHaveBeenWarnedLast(): R
    toHaveBeenWarnedTimes(n: number): R
  }
}