[Feature-request]: Add support for common AMM or liquidity pool

[montyly]

Describe the desired feature or improvement

Uniswap v2 might be a good first one

[aviggiano]

I'm compiling Uniswap v2 properties, so maybe it will help when adding this feature to the repo:

Property	Description
P-01	Adding liquidity increases K
P-02	Adding liquidity increases the total supply of LP tokens
P-03	Adding liquidity increases reserves of both tokens
P-04	Adding liquidity increases the user's LP balance
P-05	Adding liquidity decreases the user's token balances
P-06	Adding liquidity for the first time should mint LP tokens equals to the square root of the product of the token amounts minus a minimum liquidity constant
P-07	Adding liquidity should not change anything if it fails
P-08	Adding liquidity should not fail if the provided amounts are withing the valid range of uint112, would mint positive liquidity and are above the minimum initial liquidity check when minting for the first time
P-09	Removing liquidity decreases K
P-10	Removing liquidity decreases the total supply of LP tokens
P-11	Removing liquidity decreases reserves of both tokens
P-12	Removing liquidity decreases the user's LP balance
P-13	Removing liquidity increases the user's token balances
P-14	Removing liquidity should not change anything if it fails
P-15	Removing liquidity should not fail if the returned amounts to the user are greater than zero
P-16	Swapping does not decrease K
P-17	Swapping increases the sender's tokenOut balance
P-18	Swapping decreases the sender's tokenIn balance
P-19	Swapping does not decrease the feeTo LP balance
P-20	Swapping should not fail if there's enough liquidity, if the output would be positive and if the input would not overflow the valid range of uint112

I'll update the list as I add more properties.

[montyly]

This is awesome @aviggiano, thanks for doing it.

It might be worth to take a look at the automated testing section of our past reports for AMM like projects:

• https://github.com/trailofbits/publications/blob/master/reviews/UniswapV3Core.pdf
• https://github.com/trailofbits/publications/blob/master/reviews/LiquityProtocolandStabilityPoolFinalReport.pdf
• https://github.com/trailofbits/publications/blob/master/reviews/2021-04-balancer-balancerv2-securityreview.pdf
• https://github.com/trailofbits/publications/blob/master/reviews/Primitive.pdf

[aviggiano]

@montyly thanks, that's great
I'll check these out