feat: add explicit gas override to writeContract/deployContract

[ygd58]

Summary

Adds the second part of #402's ask: an explicit gas override for writeContract/deployContract, bypassing eth_estimateGas entirely.

Context

#402 reports that an exact eth_estimateGas result was used as the outer EVM gas limit on Bradbury, and the resulting transaction reverted twice — identical calldata succeeded when replayed with a larger explicit limit. No way existed to override the estimate.

On the automatic-headroom part of the ask: this repo already has withTransactionGasHeadroom (a 2x margin over the estimate), which would cover the exact numbers in #402's repro (1,319,997 estimated → 2,639,994 with headroom, comfortably above the 2,000,000 that #402 confirmed works). I checked the actual genlayer-js@1.1.8 tarball from the npm registry directly and confirmed this headroom code isn't in the published package yet — so that part of the fix exists but hasn't shipped. This PR is the complementary, still-needed part: a caller-side override for cases even the headroom doesn't cover, or for callers who just want deterministic control over gas.

Change

Added an optional gas?: bigint to writeContract and deployContract's options. When provided:

• eth_estimateGas is not called at all
• no headroom markup is applied
• the value is used exactly as given, on both the local-account (signTransaction) and external-wallet (eth_sendTransaction) send paths

Both functions already funnel through a shared _sendTransaction → sendWithEncodedData helper, so this was a single plumbing point for both.

Testing

Added 4 cases to tests/contracts-actions.test.ts, reusing the existing setupWriteContractHarness:

• explicit override bypasses eth_estimateGas entirely and is used as-is
• omitting the override still estimates and applies headroom — asserts the exact 2_639_994n value from #402's own numbers (1_319_997 * 20_000bps / 10_000)
• the override threads through deployContract the same way as writeContract

Full suite: 87 passed. eslint: clean on all changed files.

Summary by CodeRabbit

• New Features

  • Added optional gas limit overrides for contract write and deployment transactions.
  • Transactions with an explicit gas limit skip automatic gas estimation.
  • Existing automatic estimation and safety headroom remain unchanged when no override is provided.

• Tests

  • Added coverage confirming explicit gas limits are preserved and default estimation continues to work.

[github-actions]

This PR targeted main, which is only the default/static branch.

I retargeted it to v2-dev, the active development branch. Pushes to v2-dev automatically fast-forward main.

[coderabbitai]

📝 Walkthrough

Walkthrough

The contract client now accepts optional explicit gas limits for writeContract and deployContract. Explicit values bypass estimation and headroom. Transactions without overrides retain existing estimation, fallback, and headroom behavior.

Changes

Gas override support

Layer / File(s)	Summary
Public gas override API src/types/clients.ts, src/contracts/actions.ts	writeContract and deployContract now accept optional gas values and forward them to _sendTransaction.
Transaction gas selection and validation src/contracts/actions.ts, tests/contracts-actions.test.ts	_sendTransaction uses explicit gas unchanged. Without an override, it estimates gas and applies the existing 200% headroom and fallback behavior. Tests cover both paths.

Estimated code review effort: 3 (Moderate) | ~20 minutes

Sequence Diagram(s)

sequenceDiagram
  participant ContractAction as writeContract/deployContract
  participant SendTransaction as _sendTransaction
  participant EthEstimateGas as eth_estimateGas
  participant SignedTransaction as signed transaction
  ContractAction->>SendTransaction: pass optional gas override
  alt gas override provided
    SendTransaction->>SignedTransaction: use explicit gas unchanged
  else gas override absent
    SendTransaction->>EthEstimateGas: estimate gas
    EthEstimateGas-->>SendTransaction: estimated gas
    SendTransaction->>SignedTransaction: use estimated gas with 200% headroom
  end

Loading

Possibly related PRs

• genlayerlabs/genlayer-js#115: Both changes modify _sendTransaction gas-estimation behavior.

Suggested reviewers: muncleuscles, cristiam86

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely identifies the explicit gas override added to writeContract and deployContract.
Description check	✅ Passed	The description clearly covers the change, rationale, implementation details, and testing results, but it omits several template sections and checklist items.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

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[coderabbitai]

Actionable comments posted: 1

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@src/contracts/actions.ts`:
- Around line 2062-2064: Update _sendTransaction to validate gasOverride before
transaction preparation, accepting only bigint values greater than 0n and
rejecting 0n or negative overrides with the existing validation error behavior.
Add coverage for both zero and negative gasOverride values.

🪄 Autofix

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 8763eea8-2496-43ce-a29f-67486f2497bb

📥 Commits

Reviewing files that changed from the base of the PR and between 1b7f50a and 5714994.

📒 Files selected for processing (3)

• src/contracts/actions.ts
• src/types/clients.ts
• tests/contracts-actions.test.ts

[coderabbitai]

🎯 Functional Correctness | 🟠 Major | ⚡ Quick win

Reject non-positive gas overrides.

A caller can pass 0n or a negative bigint. A negative value reaches the external-wallet request as an invalid value such as 0x-1. A zero value cannot execute an EVM transaction.

Validate gasOverride > 0n in _sendTransaction before transaction preparation. Add tests for 0n and a negative value.

Proposed fix

+  if (gasOverride !== undefined && gasOverride <= 0n) {
+    throw new Error("gas must be greater than zero.");
+  }
+
   const sendWithEncodedData = async (transactionVariant: EncodedTransactionVariant) => {

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@src/contracts/actions.ts` around lines 2062 - 2064, Update _sendTransaction
to validate gasOverride before transaction preparation, accepting only bigint
values greater than 0n and rejecting 0n or negative overrides with the existing
validation error behavior. Add coverage for both zero and negative gasOverride
values.