Introduction

BuildBear facilitates it's users to fork any mainnet/testnet sandbox and allows the data from that to be run in a state-persistent testing environment to allow for it's builders to deterministically test and build robust applications and reduce margins of error.

Sometimes an issue occurs where one needs the sandbox state to constantly sync up with the mainnet state, one such case is of Uniswap V2's Reserves.

This repository equips the tools provided by BuildBear and makes it possible to sync the mainnet and sandbox state with a run of a command.

If the sandbox reserves are behind mainnet, the sandbox is funded with reserves tokens, and if it has excess it burns the reserves and syncs up the balances.

Installation

git clone https://github.com/JustUzair/buildbear-uniswapv2-balancer.git
npm i

Environment Setup

• Mainnet RPC can be obtained from chainlist.org
• BuildBear RPC can be obtained from BuildBear Dashboard
• Pair Address can be obtained by calling getPair() on Uniswap V2 Factory Contract
• Pair Address will also identify the tokens (TOKEN0, TOKEN1) addresses
• Funder Address can be the wallet address that is used to fund pair address
• Sandbox Chain ID is chain ID random, same as forked chain id for the sandbox
• Sandbox ID can be identified as follows:
  • https://rpc.buildbear.io/{SANDBOX-ID}
• Private Key is the private key for the funder address

Note

• This sync functionality works for all mainnets and testnets on networks supported by BuildBear.
• To check the list of supported RPCs and networks, refer to the BuildBear Supported RPCs page.s

MAINNET_RPC=
BUILDBEAR_RPC=
PAIR_ADDRESS=
TOKEN0=
TOKEN1=
FUNDER_ADDRESS=
SANDBOX_CHAIN_ID=
SANDBOX_ID=
PRIVATE_KEY=

Execution

Once dependencies are installed and environment setup, run the script

npm start

Correctly executing the script should produce a similar output

npm start

> uniswap-balancer@1.0.0 start
> npx tsx src/index.ts

🔄 Fetching reserves from mainnet and sandbox...
✅ Mainnet Reserves
USDC :  10123482.100533
WETH :  4880.497939626477228382
✅ Sandbox Reserves
USDC :  10121804.559038
WETH :  4881.450699071537339235
Token0 : 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48
Token1 : 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
RAW :: missingToken0 : 1677541495
RAW :: missingToken1 : 0
RAW :: excessToken0 : 0
RAW :: excessToken1 : 952759445060110853
⚠️ 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 Sandbox reserves are lower than mainnet! Minting additional tokens...
🚰 Funding Sandbox: Minting 1677.541495 of Token0 (0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48)
0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 Balance Before : 10121804.559038
🚰 Requesting BuildBear faucet for 1677541495 wei of 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48...
✅ Faucet Success: Funded 1677.541495 0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 to 0xB4e16d0168e52d35CaCD2c6185b44281Ec28C9Dc
0xA0b86991c6218b36c1d19D4a2e9Eb0cE3606eB48 Balance After : 10123482.100533
⚠️ 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 Sandbox reserves are higher than mainnet! Burning excess tokens...
🔥 Burning 0.952759445060110853 of Token1 (0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2)
✅ Burned 952759445060110853 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2 tokens
🔄 Performing sync() update the state...
✅ Pair state updated successfully with sync()
✅ Reserves adjusted successfully.
🔄 Fetching new reserves from mainnet and sandbox...
✅ Mainnet Reserves
USDC :  10123482.100533
WETH :  4880.497939626477228382
✅ Updated Sandbox Reserves
USDC :  10123482.100533
WETH :  4880.497939626477228382