vm: externalize header field validation

[ScottyPoi]

This PR externalizes the header field validation conditionals from vm.runBlock into a new fuction: validateHeaderFields exported from validateHeaderFields.ts.

Also modifies the error reporting to include all mismatches. Previously runBlock would fail at the first header field mismatch. Often this meant a invalid receiptsRoot error thrown, when in reality, multiple header fields were probably mismatched.

The new function will check all of the header fields, and report the full list of mismatched fields.

[codecov]

Codecov Report

❌ Patch coverage is 41.17647% with 20 lines in your changes missing coverage. Please review.
✅ Project coverage is 73.31%. Comparing base (186f20d) to head (c07704a).

Additional details and impacted files

Flag	Coverage Δ
block	87.33% <ø> (ø)
blockchain	88.85% <ø> (ø)
common	93.44% <ø> (ø)
evm	61.28% <ø> (ø)
mpt	89.99% <ø> (+0.33%)	⬆️
statemanager	78.10% <ø> (ø)
static	91.35% <ø> (ø)
tx	88.01% <ø> (ø)
util	80.81% <ø> (ø)
vm	55.86% <41.17%> (+0.25%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[Copilot]

Pull request overview

This PR refactors block header field validation out of vm.runBlock into a new validateHeaderFields helper, with the intended behavior change of collecting and reporting all header mismatches instead of failing fast on the first mismatch.

Changes:

• Added validateHeaderFields.ts to perform header validation and aggregate mismatches into a single error.
• Updated runBlock to call validateHeaderFields during non-generated-field execution to centralize validation logic.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
packages/vm/src/validateHeaderFields.ts	Introduces the new header validation helper and aggregated error reporting.
packages/vm/src/runBlock.ts	Replaces inline header validation with a call to validateHeaderFields.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

[github-actions]

📦 Bundle Size Analysis

Package	Size (min+gzip)	Δ
binarytree	17.5 KB	⚪ ±0%
block	43.7 KB	⚪ ±0%
blockchain	69.8 KB	⚪ ±0%
common	25.4 KB	⚪ ±0%
devp2p	17.7 KB	⚪ ±0%
e2store	87.2 KB	⚪ ±0%
ethash	61.6 KB	⚪ ±0%
evm	62.4 KB	⚪ ±0%
genesis	272.2 KB	⚪ ±0%
mpt	21.9 KB	⚪ ±0%
rlp	1.7 KB	⚪ ±0%
statemanager	41.3 KB	⚪ ±0%
testdata	43.8 KB	⚪ ±0%
tx	20.8 KB	⚪ ±0%
util	13.1 KB	⚪ ±0%
vm	154.7 KB	🔴 +0.1 KB (+0.06%)
wallet	15.0 KB	⚪ ±0%

Values are minified+gzipped bundles of each package entry. Workspace deps are bundled; external deps are excluded.

_{Generated by bundle-size workflow}

[holgerd77]

Can you give a quick reasoning why you are doing this?

[ScottyPoi]

Can you give a quick reasoning why you are doing this?

2 main reasons:

1. pulling header-field validation out of vm.runBlock keeps the block execution path smaller and easier to follow
2. reporting all header mismatches at once instead of stopping at the first one makes bad blocks and failing fixtures faster to diagnose.