fix(vue): respect emitOnBegin in useWatchBlockNumber

[pucedoteth]

useWatchBlockNumber in @wagmi/vue discards the caller's emitOnBegin.

Problem

The composable spreads the caller's parameters and then sets the option itself:

const unwatch = watchBlockNumber(config, {
  ...(rest as any),
  chainId,
  onBlockNumber,
  emitOnBegin: true,
})

The literal comes after the spread, so it always wins. Passing emitOnBegin: false has no effect — the current block is still delivered the moment the watcher subscribes, before anything is mined.

It isn't an internal knob. WatchBlockNumberParameters in @wagmi/core extends viem's, which declares emitOnBegin?: boolean | undefined, so it is part of the public type and compiles fine today:

useWatchBlockNumber({ emitOnBegin: false, onBlockNumber() {} }) // type-checks, silently ignored

The other bindings treat it as caller-controlled:

• React's useWatchBlockNumber lists rest.emitOnBegin in its effect dependencies (packages/react/src/hooks/useWatchBlockNumber.ts:67), as does useWatchBlocks
• Solid's tests pass emitOnBegin explicitly

So the same parameters behave differently depending on which binding you use. useWatchContractEvent in Vue doesn't do this — it's specific to this composable.

Change

Destructure emitOnBegin alongside the other options, keeping true as the default:

const {
  chainId = configChainId.value,
  emitOnBegin = true,
  enabled = true,
  ...
} = parameters.value

I kept the existing true default deliberately, so nothing changes for callers who don't pass the option — only an explicit value now reaches viem. Worth flagging that this leaves Vue defaulting to true while React and viem default to false; aligning those would be a behaviour change for existing Vue users, so I left that call to you.

Tests

Added a case to packages/vue/src/composables/useWatchBlockNumber.test.ts asserting emitOnBegin: false produces no callback until a block is actually mined. It fails on main (the callback fires immediately) and passes with the change.

Verification

• biome check — clean on both files; the repo's pre-commit ran biome check --write across all 1241 files with no fixes applied
• tsc --noEmit on packages/vue — clean
• Confirmed emitOnBegin: false type-checks against the composable's public parameter type

I could not run the test suite. It needs anvil forked from mainnet, and https://eth.merkle.io (the default VITE_MAINNET_FORK_URL) returns 403 from my network, so prool can't start the instances — every test in the file fails at the HTTP transport before reaching any assertion, on a clean checkout too. The new test is written against the existing harness and follows the style of the neighbouring parameters: enabled cases, but it needs a CI run to confirm.

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🦋 Changeset detected

Latest commit: f69a9ce

The changes in this PR will be included in the next version bump.

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Name	Type
@wagmi/vue	Patch

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