v1-contracts VS v2-periphery

If you're working on "large Ethereum smart contracts" you've missed the point. On chain logic should always be as minimal as possible. Uniswap v1 was two vyper files. One was 46 lines, and the other was 496 lines[1]. It took like 20 minutes to read through the code thoroughly, and was one of the most impactful contracts ever deployed to the network.

Solidity also matured a lot, which is why Uniswap v2 moved back. If you find yourself writing an EVM assembler from scratch, and you're trying to build something other than a compiler, you have veered way way off course, and need to re-evaluate your system architecture.

Feature creep might work well if you're trying to leech money from a government contract or something, or being paid by line of code you contribute, but it's fatal in the Ethereum world. I consulted for a number of projects that made the exact same mistake, and most of them aren't around anymore.

[1] https://github.com/Uniswap/uniswap-v1/tree/master/contracts

For source code, Uniswap V2 Core and Uniswap V2 Peripheral

u/lapurita is right. Uniswap has periphery contracts which are created solely to make the end user experience easier. They have a function to swap ETH for tokens, but the first step is to convert ETH to WETH and then make the swap. Take a look at the Uniswap (v2) source code to see for yourself: https://github.com/Uniswap/v2-periphery/blob/master/contracts/UniswapV2Router02.sol

UniV2Router02

Any of those above functions that have require statements could have triggered it. I guess that is why you suggested the "hardhats console log". I am not familiar with that and will get right on trying to get that to work. Sorry for slow response, it seems since your message I have went all up and down the entire uniswap code database that includes the router, pair, libraries, transferhelper, WETH, etc.... So I just had the most extensive crash course I have ever had. hahahaha... Thanks for pointing me in that direction. I have learned A LOT. Though I still haven't figured out why the error is happening so I will now try using the hardhats console log to debug it.

I've never implemented a flash swap, but I don't see where you exchange anything before your callback to resolve the initial amount. Have you seen Uniswap's full example?

However, I am having trouble importing the Uniswap/v2-periphery because the only tag is 1.0.0-beta.0 shown here. I've tried importing in the following ways with no success:

Learning about flash swaps on uniswap and I'm reading thru this example code and i noticed that this contract only has external functions.

https://github.com/pdaian/flashboys2 https://github.com/kmadorin/flashbot https://www.smartcontractresearch.org/t/research-summary-coding-a-defi-arbitrage-bot/282 https://github.com/ExtropyIO/defi-bot https://github.com/search?q=flash+loan+arbitrage https://blog.infura.io/build-a-flash-loan-arbitrage-bot-on-infura-part-i/ https://blog.infura.io/build-a-flash-loan-arbitrage-bot-on-infura-part-ii/ https://medium.datadriveninvestor.com/maximizing-your-arbitrage-flash-loans-2cbb4c99ed80 https://medium.com/flashbots/frontrunning-the-mev-crisis-40629a613752 https://github.com/Uniswap/uniswap-v2-periphery/blob/master/contracts/examples/ExampleFlashSwap.sol