feat(tests): add type-0 transaction RLP validity tests

[chfast]

Description

Port the core malformation classes of the legacy TransactionTests suites (ttWrongRLP, ttNonce, ttValue, ttRSValue, ttVValue, ttAddress), which were never converted because the ported-static pipeline only handles state-test fillers and the raw malformed bytes cannot round-trip through a structured transaction model.

A local RLP encoder builds each corruption deliberately, since a correct encoder cannot emit non-canonical forms: per-field leading zeros, 33-byte field overflows, 19 and 21 byte addresses, fields encoded as lists, structural corruptions of the outer list (truncation, trailing bytes, wrong element counts, header size mismatches, size with leading zeros), and well-encoded but invalid signature values. A valid re-encoded control case anchors the encoder to the framework's byte-exact output.

The transaction_test fixture format records the declared exception without consulting the transition tool, so all 30 cases were verified externally by feeding the generated fixture bytes through EELS decode_transaction, recover_sender and validate_transaction at Frontier, London and Cancun: every invalid vector is rejected and the control is accepted with the matching sender. Notably the gas limit and gas price are unbounded scalars in the spec, so their oversized encodings are valid at the transaction level; the overflow cases cover the 256-bit bounded fields (nonce, value, r, s) only.

Related Issues or PRs

N/A.

Checklist

• Ran fast static checks to avoid CI fails, see Code Standards & Verifying Changes: just static
• PR title has the form <type>(<area>): <title>, where <type> and <area> come from an appropriate C-<type>, respectively A-<area>, label. The title should match the target squash commit message.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 93.31%. Comparing base (0f8b81b) to head (8cd3353).
⚠️ Report is 3 commits behind head on forks/amsterdam.

Additional details and impacted files

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##           forks/amsterdam    #3156   +/-   ##
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  Coverage            93.30%   93.31%           
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  Files                  624      624           
  Lines                36991    36994    +3     
  Branches              3384     3384           
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+ Hits                 34515    34521    +6     
+ Misses                1694     1693    -1     
+ Partials               782      780    -2     

Flag	Coverage Δ
unittests	93.31% <ø> (+<0.01%)	⬆️

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[danceratopz]

Thanks @chfast! I think we have a bit of work to do regarding awareness of and ease of consuming the transaction_test format. Could you test these against evmone? If so, mind sharing how?

The other way to run transaction_test is via hive execute. I think we have a bit of work to do if that's the goal. No need to dive into this now, I'm not sure that should be the goal for these (invalid) tests, that should get rejected at the JSON RPC layer.

[danceratopz]

Added some suggestions here chfast#2. Thanks!

[chfast]

This is discussion starter for transaction decoding testing. I don't consume the transaction tests in evmone, but I plan to do so soon as I'm adding full transaction decoding capability. But this seems to be working with evmone t8n.

The alternative to specific transaction_test format is to reuse state_test format. However, then you can only have txbytes representation of the transaction (no transaction decomposed to a JSON object). For me this is fine as well as I plan to add exactly support for txbytes in evmone. I believe some Clients should be already compatible.