After some transactions:

use the following data in .env, make sure the .env.example contains their format

SCAN_API_KEY_{CHAINID}=
SCAN_API_KEY_{CHAINID}=
RPC_{CHAINID}=
RPC_{CHAINID}=

if the SCAN_API_KEY is not defined in .env, use empty as defaul
if the RPC is not defined in .env, set the default rpc URL for each chain in the code

And:

• don't use private key in tests, change the tx to callstatic to test the results
• make sure a fresh github clone can run the test
• remove the .spec prefix for non-test files (and move them to a sub folder of /test/)
• change .spec to .test for generic case test files

Intergrate free DEX aggregator API and Contract so position can be opened by any token in the network. And vice versa: closing to any token.

1inch is not free

paraswap seem to be the best option: https://developers.paraswap.network/api/master

testing for: ETH <-> rETH

UTR Flow:

1. UTR TRANSFER 10 USDT to Helper
2. Helper approve 10 USDT to ParaswapRouter
3. Helper call ParaswapRouter.data (with recipient is UTR) to receive x WETH
4. UTR call Helper.swap to open position using x WETH

Execution Flow:

• write an UT to aggAndOpen(a position with TOKEN_R = WETH using USDT as input)
• construct the engine with aggregrator params
• call paraswap api to get target and data
• construct the UTR Flow above and staticcall the data to estimate amountOut