feat: add permit single to swapCallData

[luchobonatti]

Add Permit2 Single Support to SwapCallData

Overview

This PR adds support for Permit2 single token approvals in swap transactions, allowing users to perform gas-efficient token swaps without requiring separate approval transactions.

Changes

• Added preparePermit2Data utility for handling single token approvals
• Updated buildSwapCallData to support Permit2 single signatures
• Consolidated Permit2 types into a single file
• Added comprehensive test coverage for new features

Technical Details

• preparePermit2Data handles:
  • Single token approvals
  • Native token (ETH) filtering
  • Custom deadline support
  • Current allowance fetching
• buildSwapCallData now supports:
  • Basic swaps without approvals
  • Swaps with Permit2 single signatures
  • Universal Router integration
• Consolidated types in permit2.ts:
  • Base interfaces for Permit2 data
  • Single and batch permit interfaces
  • Result interfaces with helper functions

Testing

Added test suites for:

• preparePermit2Data.test.ts covering:
  • Native token validation
  • Default and custom deadlines
  • Signature building
  • Allowance fetching
• Updated existing tests to maintain compatibility

Usage Example

// Basic swap
const { calldata, value } = await uniDevKit.buildSwapCallData({
  tokenIn: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48", // USDC
  amountIn: parseUnits("100", 6), // 100 USDC
  pool: pool,
  slippageTolerance: 50, // 0.5%
  recipient: "0x..."
});

// Swap with permit2
const permitData = await uniDevKit.preparePermit2Data({
  token: tokenIn,
  spender: uniDevKit.getContractAddress('universalRouter'),
  owner: userAddress
});

const signature = await signer._signTypedData(permitData.toSign);
const permitWithSignature = permitData.buildPermit2DataWithSignature(signature);

const { calldata: calldataWithPermit, value: valueWithPermit } = await uniDevKit.buildSwapCallData({
  tokenIn: "0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48",
  amountIn: parseUnits("100", 6),
  pool: pool,
  slippageTolerance: 50,
  recipient: "0x...",
  permit2Signature: permitWithSignature
});

const tx = await sendTransaction({
  to: uniDevKit.getContractAddress('universalRouter'),
  data: calldata,
  value
});

[github-actions]

🎉 This PR is included in version 1.0.10 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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