feat(spec, spec-specs): EIP-7997

[kclowes]

🗒️ Description

EIP-7997 implementation and tests

🔗 Related Issues or PRs

N/A.

✅ Checklist

• All: Ran fast static checks to avoid unnecessary CI fails, see also Code Standards and Enabling Pre-commit Checks:

  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.

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[codecov]

Codecov Report

❌ Patch coverage is 50.00000% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.48%. Comparing base (9d18733) to head (97a92d1).
⚠️ Report is 11 commits behind head on forks/amsterdam.

Files with missing lines	Patch %	Lines
src/ethereum/forks/amsterdam/fork.py	50.00%	2 Missing ⚠️

Additional details and impacted files

@@                 Coverage Diff                 @@
##           forks/amsterdam    #2802      +/-   ##
===================================================
- Coverage            88.17%   85.48%   -2.69%     
===================================================
  Files                  577      630      +53     
  Lines                35659    39383    +3724     
  Branches              3490     3909     +419     
===================================================
+ Hits                 31442    33668    +2226     
- Misses                3654     5055    +1401     
- Partials               563      660      +97     

Flag	Coverage Δ
unittests	85.48% <50.00%> (-2.69%)	⬇️

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[petertdavies]

Deploying a system contract in the precompile range has the potential to cause weird bugs in clients that have longstanding hardcoded assumptions that the 0x01-0xff range is only precompiles. This isn't a precompile, it's just a regular contract. The level of testing required is higher than might superficially appear from the EIP.

The included tests look pretty good, but I could think of few more:

• Test the interaction between 0x12 and access list prewarming. The EIP is silent on prewarming, as written this PR does not prewarm.
• Try CALLCODEing it.
• Give it a balance using SELFDESTRUCT.

[kclowes]

Thanks @petertdavies! I will add those! It is very strange that this is in the precompile range, but is not a precompile.

[marioevz]

Looks great so far, a few comments. Thanks!

[marioevz]

Interesting, I did not know we had this functionality!

I'm not sure though how do we signal from the tests that a block is the first block in the fork?

[kclowes]

@marioevz I'm not sure what you mean by:

I'm not sure though how do we signal from the tests that a block is the first block in the fork?

Can you clarify? AFAIK, the tests don't call apply_fork, and AIUI, we'd have to test with a pre_alloc mutable as discussed below, for inherently not a great test. This is also highlighted in the codecov report since there is not a great way to test this method. Let me know if you see another way though! I'm happy to update.

[marioevz]

Suggested change

	pytestmark = pytest.mark.valid_from("Amsterdam")
	pytestmark = pytest.mark.valid_from("EIP7997")

[marioevz]

We should test the transition to the fork where this EIP is enabled, but that circles back to my question on the first comment since I'm not really sure how we signal this in the t8n. Maybe @gurukamath has more insight.

[kclowes]

I think that the best we can do is do a pre_alloc_mutable and do something like: pre[0x12] - Account(code=b"", nonce=0, balance=0, and assert that you can call the contract, and it returns success for the call, but it doesn't return anything else. It looks like we do a similar thing here. I'm not sure how much value that test really adds though.

[kclowes]

@marioevz @petertdavies @LouisTsai-Csie - this is ready for another look when you get a chance. I added the tests @petertdavies suggested.

I'm not sure how to raise the question of whether this contract should be prewarmed - is that something that we'd generally put into the tests and see which clients fail or is it something we'd bring up in a sync call or comment on the EIP?

Edit to add: I don't think there is a way around the apply_fork coverage fail, but very happy to hear suggestions!