chore(refactor): split transactions.py:calculate_intrinsic_cost() into helper functions for maintainability

[shrirajpawar4]

🗒️ Description

Refactor Amsterdam transaction intrinsic-gas accounting into small neutral helper functions to reduce merge-conflict pressure in transactions.py.

This change keeps behavior unchanged and only restructures the intrinsic-cost pipeline in src/ethereum/forks/amsterdam/transactions.py. calculate_intrinsic_cost() now delegates to helper seams
for:

• calldata cost
• contract creation cost
• access-list cost
• authorization cost
• state-dependent intrinsic cost
• floor-gas calculation

Amsterdam behavior is preserved:

• access lists still affect intrinsic gas
• access lists still contribute zero floor tokens
• set-code transactions still charge authorization intrinsic gas
• public function signatures remain unchanged

A lightweight regression test file was added to cover legacy calldata, contract creation, access-list transactions, and set-code authorization gas.

🔗 Related Issues or PRs

Fixes #2708.

✅ Checklist

• All: Ran fast static checks to avoid unnecessary CI fails, see also Code Standards and [Enabling Pre-commit Checks](https://
  eest.ethereum.org/main/dev/precommit/):

  just static

• All: PR title adheres to the repo standard - it will be used as the squash commit
  message and should start type(scope):.
• All: Considered updating the online docs in the ./docs/ directory.
• All: Set appropriate labels for the changes (only maintainers can apply labels).
• Tests: Ran mkdocs serve locally and verified the auto-generated docs for new tests in the Test Case Reference are correctly formatted.
• Tests: For PRs implementing a missed test case, update the post-mortem document to add an entry the list.
• Ported Tests: All converted JSON/YML tests from ethereum/tests or tests/static have been assigned @ported_from marker.

Verification run:

UV_CACHE_DIR=/tmp/uv-cache just static
UV_CACHE_DIR=/tmp/uv-cache uv run pytest \
    tests/json_loader/test_transaction_codec.py \
    tests/json_loader/test_transaction_intrinsic_cost.py -q

Cute Animal Picture

[felix314159]

ty for taking a look at this. i think you can further extend this: where is calculate_floor_tokens_in_calldata()? it should get its own dedicated helper instead of being implicitly tied to count_tokens_in_data(). additionally, right now calculate_intrinsic_access_list_cost() still mixes two concepts in one helper: intrinsic access-list gas and floor-token-derived gas. right now it still returns access_list_cost + tokens_in_access_list * GAS_TX_DATA_TOKEN_FLOOR, which means future access-list floor-token work still crosses seams instead of being isolated in floor-token helpers

[shrirajpawar4]

Thanks for the review @felix314159 . I extended the split so the seams are now concept-pure:

• added calculate_floor_tokens_in_calldata()
• made calculate_intrinsic_access_list_cost() return only intrinsic access-list gas
• kept floor-token-derived gas isolated to the floor-token helpers and calculate_data_floor_gas_cost()

So future access-list floor-token work should no longer cross the intrinsic access-list seam.

[felix314159]

thanks for the swift commit! there is a bit more to do:

• extract seams from validate_transaction()
• let calculate_intrinsic_cost() assemble regular/state/floor through helpers instead of flattening back to one Uint too early

the context of the issue you are solving is that the script .github/scripts/build_devnet_branch.py should be able to take forks/amsterdam as base fork and then merge EIP branches like 7981 and 8037 into it without a merge conflict. so far your PR is great for the 7981 part, but for 8037 the problem is that validate_transaction() is still too monolithic and we should split it too

[shrirajpawar4]

this makes sense.

My current changes are scoped narrow, but I see your point that the actual merge-base goal is broader.
I’ll update the PR in that direction.

I understand the remaining work as:

• extract independent seams from validate_transaction()
• let calculate_intrinsic_cost() compose regular/state/floor through grouped helpers.

am i missing anything?

[felix314159]

whether you missed something or not can only be answered after seeing the code :D but your plan looks reasonable

[shrirajpawar4]

hey @felix314159
Updated this branch to the latest forks/amsterdam and kept the refactor aligned with the current upstream GasCosts structure.

Done:

• split validate_transaction() into dedicated validation helpers
• made calculate_intrinsic_cost() compose regular/state/floor via helpers
• kept floor-token accounting separate from intrinsic access-list gas
• added focused regression tests

Verification:

• UV_CACHE_DIR=/tmp/uv-cache uv run pytest tests/json_loader/test_transaction_intrinsic_cost.py tests/json_loader/test_transaction_validation.py
• UV_CACHE_DIR=/tmp/uv-cache uv run ruff check src/ethereum/forks/amsterdam/transactions.py tests/json_loader/test_transaction_intrinsic_cost.py tests/json_loader/test_transaction_validation.py

I also checked current upstream/eips/amsterdam/eip-7981 and upstream/eips/amsterdam/eip-8037 against this branch. Both still conflict in src/ethereum/forks/amsterdam/transactions.py; from the
merge hunks, those conflicts are now due to the current EIP branches targeting older / broader transaction-cost API shapes, not because validate_transaction() or calculate_intrinsic_cost() remain
monolithic here.

If you think there is a refactor that would reduce these conflicts, I’m happy to make a followup change here.