HMRContext Class — vite Architecture

Source Code

packages/vite/src/shared/hmr.ts lines 24–168

export class HMRContext implements ViteHotContext {
  private newListeners: CustomListenersMap

  constructor(
    private hmrClient: HMRClient,
    private ownerPath: string,
  ) {
    if (!hmrClient.dataMap.has(ownerPath)) {
      hmrClient.dataMap.set(ownerPath, {})
    }

    // when a file is hot updated, a new context is created
    // clear its stale callbacks
    const mod = hmrClient.hotModulesMap.get(ownerPath)
    if (mod) {
      mod.callbacks = []
    }

    // clear stale custom event listeners
    const staleListeners = hmrClient.ctxToListenersMap.get(ownerPath)
    if (staleListeners) {
      for (const [event, staleFns] of staleListeners) {
        const listeners = hmrClient.customListenersMap.get(event)
        if (listeners) {
          hmrClient.customListenersMap.set(
            event,
            listeners.filter((l) => !staleFns.includes(l)),
          )
        }
      }
    }

    this.newListeners = new Map()
    hmrClient.ctxToListenersMap.set(ownerPath, this.newListeners)
  }

  get data(): any {
    return this.hmrClient.dataMap.get(this.ownerPath)
  }

  accept(deps?: any, callback?: any): void {
    if (typeof deps === 'function' || !deps) {
      // self-accept: hot.accept(() => {})
      this.acceptDeps([this.ownerPath], ([mod]) => deps?.(mod))
    } else if (typeof deps === 'string') {
      // explicit deps
      this.acceptDeps([deps], ([mod]) => callback?.(mod))
    } else if (Array.isArray(deps)) {
      this.acceptDeps(deps, callback)
    } else {
      throw new Error(`invalid hot.accept() usage.`)
    }
  }

  // export names (first arg) are irrelevant on the client side, they're
  // extracted in the server for propagation
  acceptExports(
    _: string | readonly string[],
    callback?: (data: any) => void,
  ): void {
    this.acceptDeps([this.ownerPath], ([mod]) => callback?.(mod))
  }

  dispose(cb: (data: any) => void): void {
    this.hmrClient.disposeMap.set(this.ownerPath, cb)
  }

  prune(cb: (data: any) => void): void {
    this.hmrClient.pruneMap.set(this.ownerPath, cb)
  }

  // Kept for backward compatibility (#11036)
  // eslint-disable-next-line @typescript-eslint/no-empty-function
  decline(): void {}

  invalidate(message: string): void {
    const firstInvalidatedBy =
      this.hmrClient.currentFirstInvalidatedBy ?? this.ownerPath
    this.hmrClient.notifyListeners('vite:invalidate', {
      path: this.ownerPath,
      message,