[WIP - not ready for review] feat: add watcher to hardhat node

[galargh]

• [ ] Because this PR includes a bug fix, relevant tests have been included.
• [ ] Because this PR includes a new feature, the change was previously discussed on an Issue or with someone from the team.
• [x] I didn't do anything of this.

---

This PR adds build info watcher to the node task. It uses chokidar instead of built-in fs.watch because https://github.com/paulmillr/chokidar?tab=readme-ov-file#why

The way we use watcher here is very similar to how we used it in HH2. See https://github.com/NomicFoundation/hardhat/blob/b914c6c00f1ef8e47a895bb75a38b766882d792c/packages/hardhat-core/src/builtin-tasks/utils/watch.ts

The main differences are that we now handle changes to both build info files and their outputs, and that we also react to the change events in addition to the add events.

[changeset-bot[bot]]

🦋 Changeset detected

Latest commit: c5301dee06be8e160621feeae8339ff625a79a02

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

This PR includes changesets to release 21 packages

Name	Type
hardhat	Patch
@nomicfoundation/hardhat-errors	Patch
@nomicfoundation/hardhat-ethers-chai-matchers	Patch
@nomicfoundation/hardhat-ignition	Patch
@nomicfoundation/ignition-core	Patch
@nomicfoundation/hardhat-ignition-ethers	Patch
@nomicfoundation/ignition-ui	Patch
@nomicfoundation/hardhat-ignition-viem	Patch
@nomicfoundation/hardhat-keystore	Patch
@nomicfoundation/hardhat-mocha	Patch
@nomicfoundation/hardhat-network-helpers	Patch
@nomicfoundation/hardhat-node-test-reporter	Patch
@nomicfoundation/hardhat-node-test-runner	Patch
@nomicfoundation/hardhat-test-utils	Patch
@nomicfoundation/hardhat-typechain	Patch
@nomicfoundation/hardhat-utils	Patch
@nomicfoundation/hardhat-toolbox-mocha-ethers	Patch
@nomicfoundation/hardhat-verify	Patch
@nomicfoundation/hardhat-viem	Patch
@nomicfoundation/hardhat-viem-assertions	Patch
@nomicfoundation/hardhat-zod-utils	Patch

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Name	Status	Preview	Comments	Updated (UTC)
hardhat	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	Apr 14, 2025 8:38pm

[github-actions[bot]]

hardhat

Total size of the bundle: 196M Total number of dependencies (including transitive): 48

List of dependencies (sorted by size)

190M	total
24M	@ignored/edr-optimism-linux-x64-musl
24M	@ignored/edr-optimism-linux-x64-gnu
22M	@ignored/edr-optimism-win32-x64-msvc
21M	@ignored/edr-optimism-linux-arm64-musl
21M	@ignored/edr-optimism-linux-arm64-gnu
20M	esbuild
18M	@ignored/edr-optimism-darwin-x64
17M	@ignored/edr-optimism-darwin-arm64
6.2M	@sentry/core
2.7M	micro-eth-signer
2.6M	zod
1.9M	@noble/curves
1.7M	undici
1.2M	@noble/hashes
864K	@streamparser/json
860K	@nomicfoundation/hardhat-utils
624K	micro-packed
592K	tsx
544K	fast-equals
544K	@nomicfoundation/hardhat-errors
492K	@scure/bip39
408K	json-stream-stringify
368K	ethereum-cryptography
348K	@ignored/edr
332K	@streamparser/json-node
320K	enquirer
304K	@ignored/edr-optimism
288K	semver
196K	ws
180K	chokidar
168K	@scure/base
136K	get-tsconfig
136K	adm-zip
96K	@scure/bip32
92K	chalk
72K	@nomicfoundation/solidity-analyzer
68K	debug
64K	@nomicfoundation/hardhat-zod-utils
60K	readdirp
56K	rfdc
48K	ansi-colors
44K	resolve.exports
40K	resolve-pkg-maps
36K	p-map
24K	strip-ansi
24K	env-paths
24K	ansi-regex
20K	ms

[galargh]

This is replaced by https://github.com/NomicFoundation/hardhat/pull/6928