wagmi/src/hooks/useWatchBlocks.ts

React Hooks for Ethereum

'use client'
import {
  type Config,
  type ResolvedRegister,
  type WatchBlocksParameters,
  watchBlocks,
} from '@wagmi/core'
import type {
  ConfigParameter,
  EnabledParameter,
  UnionCompute,
  UnionExactPartial,
} from '@wagmi/core/internal'
import { useEffect, useRef } from 'react'
import type { BlockTag } from 'viem'
import { useChainId } from './useChainId.js'
import { useConfig } from './useConfig.js'

export type UseWatchBlocksParameters<
  includeTransactions extends boolean = false,
  blockTag extends BlockTag = 'latest',
  config extends Config = Config,
  chainId extends
    config['chains'][number]['id'] = config['chains'][number]['id'],
> = UnionCompute<
  UnionExactPartial<
    WatchBlocksParameters<includeTransactions, blockTag, config, chainId>
  > &
    ConfigParameter<config> &
    EnabledParameter
>

export type UseWatchBlocksReturnType = void

/** https://wagmi.sh/react/hooks/useWatchBlocks */
export function useWatchBlocks<
  config extends Config = ResolvedRegister['config'],
  chainId extends
    config['chains'][number]['id'] = config['chains'][number]['id'],
  includeTransactions extends boolean = false,
  blockTag extends BlockTag = 'latest',
>(
  parameters: UseWatchBlocksParameters<
    includeTransactions,
    blockTag,
    config,
    chainId
  > = {} as any,
): UseWatchBlocksReturnType {
  const { enabled = true, onBlock, config: _, ...rest } = parameters

  const config = useConfig(parameters)
  const configChainId = useChainId({ config })
  const chainId = parameters.chainId ?? configChainId

  const onBlockRef = useRef(onBlock)
  const onErrorRef = useRef(rest.onError)
  onBlockRef.current = onBlock
  onErrorRef.current = rest.onError

  // TODO(react@19): cleanup
  // biome-ignore lint/correctness/useExhaustiveDependencies: `rest` changes every render so only including properties in dependency array
  useEffect(() => {
    if (!enabled) return
    if (!onBlockRef.current) return
    return watchBlocks(config, {
      ...(rest as any),
      chainId,
      onBlock: (block, prevBlock) =>
        onBlockRef.current?.(block as any, prevBlock as any),
      onError: (error) => onErrorRef.current?.(error),
    })
  }, [
    chainId,
    config,
    enabled,
    ///
    rest.blockTag,
    rest.emitMissed,
    rest.emitOnBegin,
    rest.includeTransactions,
    rest.poll,
    rest.pollingInterval,
    rest.syncConnectedChain,
  ])
}