feat: Support LP token swaps on UniswapV2

[kayibal]

Context

Swapping into and out of LP tokens is not widely supported likely due to the complexity of receiving or spending multiple tokens during the transaction. We will handle the additional tokens within the same pool, ensuring that the process of interacting with LP tokens mimics the simplicity of a standard-token swap.

Key Interfaces

No interface changes are required within this repository to support this feature. All necessary logic is to be implemented within the ProtocolSim trait.

Technical Details

• Add the following fields to the struct:

  • liquidity
  • total_supply

• Implement the following methods:

  • mint: Handle the addition of liquidity and LP token issuance.
  • burn: Handle the removal of liquidity and LP token redemption.

• Adjust the get_amount_out logic:

  • Trigger the mint and burn methods as needed.
  • Swap any remaining amount of the superfluous token into the out_token.

• Implement spot price estimation for cases involving LP tokens:

  • Example: If a pool has 10 LP tokens, 10 ETH, and 1000 USDC:
  • Spot price for 1 LP token in USDC:
  • 1 LP = 1 ETH * spot_price(ETH, USDC) + 100 USDC = 200 USDC

• Update Executor contracts: feat: Support LP token swaps on UniswapV2 tycho-execution#30

• Update Indexing logic: feat: Support LP token swaps on UniswapV2 tycho-protocol-sdk#141

Dialogue / Q&A

• Q: Why are we swapping on a pool after withdrawing liquidity?
  A: We are aware that this approach is suboptimal but are prioritizing simplicity over optimization for this implementation.

[kcraftcode]

Hello @kayibal @Haikane @pistomat @michcio1234 @tvinagre
How are you?
I’m Hitoshi Sasaki, a full-stack web and blockchain developer, and an active open source contributor on GitHub.

To support LP token swaps on UniswapV2, I plan to extend the ProtocolSim trait by implementing mint and burn functions based on UniswapV2Pair’s core logic. I’ll enhance get_amount_out to handle LP token interactions and post-burn token conversions, and introduce accurate spot price estimation for LP tokens. This will enable seamless LP token swaps while maintaining full compatibility with the existing architecture.

I'm excited about the opportunity to contribute to your team and help drive this project forward.