Clarification Request: SwapRouter vs SwapRouter02 in Uniswap V3 Tests

[sartios]

Hi,

This is a request for extra documentation in order to understand in depth the contracts used in test_exactInputSingle().

From the official documentation of Uniswap v3, there are two routers deployed:

Router	Address	Code
SwapRouter	0xE592427A0AEce92De3Edee1F18E0157C05861564	https://github.com/Uniswap/v3-periphery/blob/v1.0.0/contracts/SwapRouter.sol
SwapRouter02	0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45	https://github.com/Uniswap/swap-router-contracts/blob/main/contracts/SwapRouter02.sol

In the test cases, the address of SwapRouter02 is used along with a custom interface that is identical to the following:
https://github.com/Uniswap/swap-router-contracts/blob/main/contracts/interfaces/IV3SwapRouter.sol
In fact, importing this interface results in tests working as expected.

In order for the test case to work with SwapRouter from v3-periphery, the test should import from v3-periphery and provide the deadline property along with the rest. This property is used in a modifier to time-bound the swap, which sounds reasonable.

The official documentation of Uniswap v3 is around SwapRouter of v3-periphery, however, both contracts were deployed from Uniswap.

It is confusing which one to use and why.
As it turns out from the following open issue: Uniswap/swap-router-contracts#48 it is confusing for other people too. LLMs provide an explanation, but there are chances they hallucinate.

I would appreciate any explanation/documentation to read further.

Thank you in advance, and keep up the great work!

[EngrPips]

@t4sk, your insight would be greatly appreciated sir.

[t4sk]

SwapRouter02 was deployed shortly after SwapRouter
https://etherscan.io/address/0xE592427A0AEce92De3Edee1F18E0157C05861564
https://etherscan.io/address/0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45

What's the difference?

SwapRouter only works with Uniswap V2.
SwapRouter02 supports Uniswap V2 and V3.

Why SwapRouter02 is used in the exercises?

No important reason. Because it looked like an improvement on SwapRouter
There is also UniversalRouter but using this would be out of scope for Uniswap V3 course.

[EngrPips]

SwapRouter02 was deployed shortly after SwapRouter https://etherscan.io/address/0xE592427A0AEce92De3Edee1F18E0157C05861564 https://etherscan.io/address/0x68b3465833fb72A70ecDF485E0e4C7bD8665Fc45

What's the difference?

SwapRouter only works with Uniswap V2. SwapRouter02 supports Uniswap V2 and V3.

Why SwapRouter02 are used in the exercises?

No important reason. Because it looked like an improvement on SwapRouter There is also UniversalRouter but using this would be out of scope for Uniswap V3 course.

Thanks for the response, sir.

[sartios]

Hi, thank you both.

SwapRouter only works with Uniswap V2.
Kindly asking whether V2 is a typo as Uniswap mentions this contract in the deployments of V3:
https://docs.uniswap.org/contracts/v3/reference/deployments/ethereum-deployments

[t4sk]

SwapRouter only works with Uniswap V2.

I think both V2 and V3 have routers named SwapRouter
The link I pasted above for SwapRouter only works for V3