fix: invalid Filecoin.GasEstimateGasPremium & Filecoin.GasEstimateFeeCap response type

[LesnyRumcajs]

Summary of changes

Changes introduced in this pull request:

• fixed invalid RPC signature for Filecoin.GasEstimateGasPremium + test

Reference issue to close (if applicable)

Closes #7227

Other information and links

Change checklist

• I have performed a self-review of my own code,
• I have made corresponding changes to the documentation. All new code adheres to the team's documentation standards,
• I have added tests that prove my fix is effective or that my feature works (if possible),
• I have made sure the CHANGELOG is up-to-date. All user-facing changes should be reflected in this document.

Outside contributions

• I have read and agree to the CONTRIBUTING document.
• I have read and agree to the AI Policy document. I understand that failure to comply with the guidelines will lead to rejection of the pull request.

Summary by CodeRabbit

Release Notes

• Bug Fixes

  • Corrected the gas estimation API responses for Filecoin.GasEstimateFeeCap and Filecoin.GasEstimateGasPremium to return whole integer values instead of fractional results.

• Tests

  • Improved API comparison and validation for gas estimation: negative fee caps/premiums are now rejected, and results are checked for consistency between implementations within a 5% tolerance.
  • Updated the API comparison filter list to mark Filecoin.GasEstimateFeeCap as not supported by the Lotus gateway.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository UI

Review profile: CHILL

Plan: Pro

Run ID: 53d5e4c6-10ca-414a-ba74-66f04d8ae5f6

📥 Commits

Reviewing files that changed from the base of the PR and between 9163515 and 7a12281.

📒 Files selected for processing (1)

• src/tool/subcommands/api_cmd/api_compare_tests.rs

🔗 Linked repositories identified

CodeRabbit considers these linked repositories for cross-repo context during reviews:

• filecoin-project/lotus (manual)

🚧 Files skipped from review as they are similar to previous changes (1)

• src/tool/subcommands/api_cmd/api_compare_tests.rs

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Walkthrough

Two RPC methods, GasEstimateFeeCap and GasEstimateGasPremium, change their response type from String to TokenAmount, removing the .to_string() conversion in their handlers. API comparison tests are extended with non-negativity checks and a ±5% Forest-vs-Lotus bound for both methods. A changelog entry documents the fix, and a test filter is updated to mark GasEstimateFeeCap as unsupported by lotus-gateway.

Changes

Gas Estimate Return Type Fix

Layer / File(s)	Summary
Return type and handler changes src/rpc/methods/gas.rs, CHANGELOG.md	type Ok is changed from String to TokenAmount for both GasEstimateFeeCap and GasEstimateGasPremium, and the .to_string() conversion is removed from each handle implementation so the computed TokenAmount is returned directly. Changelog entry added under Fixed.
API comparison test validation src/tool/subcommands/api_cmd/api_compare_tests.rs, scripts/tests/api_compare/filter-list-gateway	message.clone() is used for GasEstimateMessageGas to keep message available. Two new RpcTest::validate cases are added: one for GasEstimateGasPremium and one for GasEstimateFeeCap, each asserting non-negative results and that Forest's value is within 5% of Lotus. Gateway filter is updated to mark GasEstimateFeeCap as unsupported.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Suggested reviewers

• akaladarshi
• hanabi1224

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title accurately describes the main change: fixing response types for two RPC methods from String to TokenAmount/BigInt.
Linked Issues check	✅ Passed	All three completion criteria from #7227 are met: (1) String→BigInt conversion fixed by changing response type to TokenAmount, (2) test coverage added via validators in api_compare_tests.rs, (3) audit conducted.
Out of Scope Changes check	✅ Passed	All changes are directly related to fixing the RPC response types and corresponding test coverage. No out-of-scope modifications detected.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix-gas-estimate-gas-premium-output

✨ Simplify code

• Create PR with simplified code
• Commit simplified code in branch fix-gas-estimate-gas-premium-output

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[codecov]

Codecov Report

❌ Patch coverage is 0% with 2 lines in your changes missing coverage. Please review.
✅ Project coverage is 64.01%. Comparing base (08d39a2) to head (7a12281).
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
src/rpc/methods/gas.rs	0.00%	2 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/rpc/methods/gas.rs	86.59% <0.00%> (+0.48%)	⬆️

... and 4 files with indirect coverage changes

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[LesnyRumcajs]

There might be even more problems with those methods...