feat(tests): cover EXTCODESIZE/EXTCODECOPY surcharge on empty accounts#8
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marioevz merged 2 commits intoJun 23, 2026
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The EIP-8038 code-read surcharge (`+WARM_ACCESS`) is added before the account is read, with no emptiness guard, so an empty or non-existent target still costs cold `3100` / warm `200`. The suite previously measured these two opcodes only against code-bearing targets, leaving the empty-account path unverified: A client that skipped the second read for code-less accounts would have gone uncaught. Add three tests against a non-existent `0xDEAD` target: The cold/warm surcharge for both opcodes, `EXTCODESIZE` returning `0` while still charged, and `EXTCODECOPY` composing the surcharge additively with the per-word copy and memory-expansion costs.
marioevz
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Jun 23, 2026
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Some comments just to simplify and make the tests more maintainable. Thanks!
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Add tests pinning that the EIP-8038
EXTCODESIZE/EXTCODECOPYcode-read surcharge (+WARM_ACCESS) is charged unconditionally, including against an empty or non-existent account, whereEXTCODESIZEreturns0andEXTCODECOPYcopies zeros.In the spec the surcharge is added after the warm/cold branch and before the account is read, with no emptiness guard (
amsterdam/vm/instructions/environment.py,extcodesizeandextcodecopy), so an empty target still costs cold3100/ warm200, exactly like a code-bearing target. The suite previously measured these two opcodes only against code-bearing targets: The sole empty-accountEXT*test coveredEXTCODEHASH, which carries no surcharge, so a client that skipped the second read for code-less accounts would have gone uncaught.New tests (
tests/amsterdam/eip8038_state_access_gas_cost_increase/test_ext_code_opcodes_gas.py):test_ext_code_double_read_empty_account: ChargesEXTCODESIZE/EXTCODECOPYagainst0xDEAD, cold and warm, asserting3100/200and cross-checking the opcode model.test_extcodesize_empty_account_returns_zero: Asserts the surcharge alongside a returned size of0, usingstop=Falseso the size check is not dead code after the auto-appendedSTOP.test_extcodecopy_empty_account_composes_additively: Copies 32 and 96 bytes from the empty source, asserting the surcharge composes additively with the per-word copy and memory-expansion costs.Verified on Amsterdam: All parametrizations fill, and the execution traces show the measured opcode charging
3100(cold) /200(warm) against0xDEADwithEXTCODESIZEreturning0. Coverage addition only: No spec or fixture behavior changes.🔗 Related Issues or PRs