Feature Request: Simplify createReconciler

[ahaoboy]

React version:

    "react": "19.1.0",
    "react-dom": "19.1.0",
    "react-reconciler": "0.32.0",

    "@types/react": "19.1.3",
    "@types/react-dom": "19.1.3",
    "@types/react-reconciler": "0.32.0",

Steps To Reproduce

The parameters of the createReconciler function are too complex. Is it possible to provide default values?

Using vscode to autocomplete the createReconciler function, it's very complicated

createReconciler({
  supportsMutation: false,
  supportsPersistence: false,
  createInstance: function (type: unknown, props: unknown, rootContainer: unknown, hostContext: unknown, internalHandle: createReconciler.OpaqueHandle): unknown {
    throw new Error("Function not implemented.")
  },
  createTextInstance: function (text: string, rootContainer: unknown, hostContext: unknown, internalHandle: createReconciler.OpaqueHandle): unknown {
    throw new Error("Function not implemented.")
  },
  appendInitialChild: function (parentInstance: unknown, child: unknown): void {
    throw new Error("Function not implemented.")
  },
  finalizeInitialChildren: function (instance: unknown, type: unknown, props: unknown, rootContainer: unknown, hostContext: unknown): boolean {
    throw new Error("Function not implemented.")
  },
  shouldSetTextContent: function (type: unknown, props: unknown): boolean {
    throw new Error("Function not implemented.")
  },
  getRootHostContext: function (rootContainer: unknown): unknown {
    throw new Error("Function not implemented.")
  },
  getChildHostContext: function (parentHostContext: unknown, type: unknown, rootContainer: unknown): unknown {
    throw new Error("Function not implemented.")
  },
  getPublicInstance: function (instance: unknown): unknown {
    throw new Error("Function not implemented.")
  },
  prepareForCommit: function (containerInfo: unknown): Record<string, any> | null {
    throw new Error("Function not implemented.")
  },
  resetAfterCommit: function (containerInfo: unknown): void {
    throw new Error("Function not implemented.")
  },
  preparePortalMount: function (containerInfo: unknown): void {
    throw new Error("Function not implemented.")
  },
  scheduleTimeout: function (fn: (...args: unknown[]) => unknown, delay?: number): unknown {
    throw new Error("Function not implemented.")
  },
  cancelTimeout: function (id: unknown): void {
    throw new Error("Function not implemented.")
  },
  noTimeout: undefined,
  isPrimaryRenderer: false,
  getInstanceFromNode: function (node: any): createReconciler.Fiber | null | undefined {
    throw new Error("Function not implemented.")
  },
  beforeActiveInstanceBlur: function (): void {
    throw new Error("Function not implemented.")
  },
  afterActiveInstanceBlur: function (): void {
    throw new Error("Function not implemented.")
  },
  prepareScopeUpdate: function (scopeInstance: any, instance: any): void {
    throw new Error("Function not implemented.")
  },
  getInstanceFromScope: function (scopeInstance: any): unknown {
    throw new Error("Function not implemented.")
  },
  detachDeletedInstance: function (node: unknown): void {
    throw new Error("Function not implemented.")
  },
  supportsHydration: false,
  NotPendingTransition: undefined,
  HostTransitionContext: undefined,
  setCurrentUpdatePriority: function (newPriority: createReconciler.EventPriority): void {
    throw new Error("Function not implemented.")
  },
  getCurrentUpdatePriority: function (): createReconciler.EventPriority {
    throw new Error("Function not implemented.")
  },
  resolveUpdatePriority: function (): createReconciler.EventPriority {
    throw new Error("Function not implemented.")
  },
  resetFormInstance: function (form: unknown): void {
    throw new Error("Function not implemented.")
  },
  requestPostPaintCallback: function (callback: (time: number) => void): void {
    throw new Error("Function not implemented.")
  },
  shouldAttemptEagerTransition: function (): boolean {
    throw new Error("Function not implemented.")
  },
  trackSchedulerEvent: function (): void {
    throw new Error("Function not implemented.")
  },
  resolveEventType: function (): null | string {
    throw new Error("Function not implemented.")
  },
  resolveEventTimeStamp: function (): number {
    throw new Error("Function not implemented.")
  },
  maySuspendCommit: function (type: unknown, props: unknown): boolean {
    throw new Error("Function not implemented.")
  },
  preloadInstance: function (type: unknown, props: unknown): boolean {
    throw new Error("Function not implemented.")
  },
  startSuspendingCommit: function (): void {
    throw new Error("Function not implemented.")
  },
  suspendInstance: function (type: unknown, props: unknown): void {
    throw new Error("Function not implemented.")
  },
  waitForCommitToBeReady: function (): ((initiateCommit: (...args: unknown[]) => unknown) => (...args: unknown[]) => unknown) | null {
    throw new Error("Function not implemented.")
  }
})

For example, HostTransitionContext, in "@types/react-reconciler": "0.31.0", I didn't pass in this parameter, and its default value seems to be

react/packages/react-native-renderer/src/ReactFiberConfigFabric.js

Line 716 in e5a8de8

export const HostTransitionContext: ReactContext<TransitionStatus> = {

?

Can this parameter be optional for custom renderers that don't need animation?

"@types/react-reconciler": "0.32.0" requires the following functions compared to "@types/react-reconciler": "0.31.0"
I believe that in most cases you can use the default implementation or provide a default error function? When you really need to use custom functions, add your own custom functions

    NotPendingTransition: undefined,
    resetFormInstance: function (): void {
      throw new Error("Function not implemented.")
    },
    requestPostPaintCallback: function (): void {
      throw new Error("Function not implemented.")
    },
    shouldAttemptEagerTransition: function (): boolean {
      throw new Error("Function not implemented.")
    },
    trackSchedulerEvent: function (): void {
      throw new Error("Function not implemented.")
    },
    resolveEventType: function (): null | string {
      throw new Error("Function not implemented.")
    },
    resolveEventTimeStamp: function (): number {
      throw new Error("Function not implemented.")
    },
    preloadInstance: function (): boolean {
      throw new Error("Function not implemented.")
    },
    startSuspendingCommit: function (): void {
      throw new Error("Function not implemented.")
    },
    suspendInstance: function (): void {
      throw new Error("Function not implemented.")
    },
    waitForCommitToBeReady: function (): ((initiateCommit: (...args: unknown[]) => unknown) => (...args: unknown[]) => unknown) | null {
      throw new Error("Function not implemented.")
    },
    HostTransitionContext: undefined

[sophiebits]

The API here isn't designed to be especially ergonomic for people looking to build a simple renderer. In fact we'd probably rather that you are consciously aware of all of the things you aren't implementing because it probably means your renderer won't work with all React features. I'll close this since we are not focused currently on making it easier to implement a new renderer.