Add support for the Filecoin.EthGetTransactionByBlockNumberAndIndex V2

[sudo-shashank]

Summary of changes

Changes introduced in this pull request:

• Impl Filecoin.EthGetTransactionByBlockNumberAndIndex V2 and added test.

Reference issue to close (if applicable)

Closes #6302

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.

Summary by CodeRabbit

• New Features

  • Added eth_getTransactionByBlockNumberAndIndex RPC method and a v2 API variant supporting extended block identifiers.

• Tests

  • Added tests covering the new method across multiple block types and API versions; new test snapshots included.

• Documentation

  • Added changelog entry announcing the new RPC method.

• Chores

  • Updated offline test ignore list to include the new method variants.

_{✏️ Tip: You can customize this high-level summary in your review settings.}

[coderabbitai]

Walkthrough

Adds a V2 RPC variant for Filecoin.EthGetTransactionByBlockNumberAndIndex, extracts the transaction-by-block-index logic into a shared helper, updates RPC registration, and adds tests, snapshots, and filter-list entries for the new method.

Changes

Cohort / File(s)	Summary
Changelog & Test Filters CHANGELOG.md, scripts/tests/api_compare/filter-list-offline	Added changelog entry for the new V2 RPC method; added two ignore entries to offline test filter for the new method names.
RPC Methods & Routing src/rpc/methods/eth.rs, src/rpc/mod.rs	Introduced EthGetTransactionByBlockNumberAndIndexV2, added DESCRIPTION metadata, refactored block-index lookup into eth_tx_by_block_num_and_idx(...), and registered the V2 method in RPC enumeration.
Tests & Snapshots src/tool/subcommands/api_cmd/api_compare_tests.rs, src/tool/subcommands/api_cmd/test_snapshots.txt	Added API-compare tests covering V1/V2 variants and predefined block params; added five new snapshot entries for the method variants.

Sequence Diagram(s)

sequenceDiagram
    participant Client
    participant RPC as "RPC Module"
    participant Eth as "eth.rs:Handler"
    participant Tipset as "Tipset Resolver"
    participant Helper as "eth_tx_by_block_num_and_idx"
    participant Chain as "Chain/State"

    Client->>RPC: Filecoin.EthGetTransactionByBlockNumberAndIndex[V2] request
    RPC->>Eth: route to handler (V1 or V2)
    Eth->>Tipset: resolve tipset (block number/hash or V2 param)
    Tipset-->>Eth: return Tipset
    Eth->>Helper: fetch transaction at index from Tipset
    Helper->>Chain: read messages/state for Tipset
    Chain-->>Helper: messages & state
    Helper-->>Eth: ApiEthTx | None
    Eth-->>RPC: response (ApiEthTx or null)
    RPC-->>Client: RPC response

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~22 minutes

Possibly related PRs

• fix(rpc): register RPC methods for different versions into different modules #6219: Modifies RPC method registration and per-version registration patterns relevant to adding V2 variants.
• feat: enable V2 API support for basic Eth and Filecoin RPC methods #6171: Changes in src/rpc/methods/eth.rs enabling V2 API support that overlap with this PR's V2 additions.

Suggested reviewers

• LesnyRumcajs
• akaladarshi

🚥 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 'Add support for the Filecoin.EthGetTransactionByBlockNumberAndIndex V2' directly summarizes the primary change: implementing the V2 variant of the EthGetTransactionByBlockNumberAndIndex RPC method.
Linked Issues check	✅ Passed	The implementation adds the V2 RPC method with comprehensive tests, snapshots, and documentation updates, fulfilling the requirements from linked issue #6302.
Out of Scope Changes check	✅ Passed	All changes are directly related to implementing the EthGetTransactionByBlockNumberAndIndexV2 method and its associated testing/documentation; no unrelated modifications detected.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

---

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[codecov]

Codecov Report

❌ Patch coverage is 81.48148% with 5 lines in your changes missing coverage. Please review.
✅ Project coverage is 58.71%. Comparing base (0292008) to head (d7f2d58).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
src/rpc/methods/eth.rs	81.48%	0 Missing and 5 partials ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
src/rpc/mod.rs	24.47% <ø> (ø)
src/rpc/methods/eth.rs	67.96% <81.48%> (+0.28%)	⬆️

... and 14 files with indirect coverage changes

---

Continue to review full report in Codecov by Sentry.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 0292008...d7f2d58. Read the comment docs.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.