Sealevel native warp route adapter does not account for rent balance

[yorhodes]

Problem

The native sealevel token adapter queries the balance held by the collateral account to check if the requested amount is available to be withdrawn. However, all Sealevel accounts with non-zero data must have a minimum balance to avoid being pruned by the network (referred to as Rent).

The current implementation does not account for this minimum balance requirement, which can lead to the adapter returning a false negative when checking if the requested amount is available to be withdrawn.

Solution

The adapter should account for the minimum balance requirement when checking if the requested amount is available to be withdrawn. This can be done by adding the minimum balance to the requested amount before querying the balance held by the collateral account.

The way to do this would be:

• get the account data length of collateralAccount via an RPC call (the data len is 0 for this collateral account)
• use the Solana SDK to calculate the required rent (we can't hardcode this bc it's different on Solana vs Eclipse)

Example showing the rent via the CLI:

Solana mainnet

$ solana rent 0 -u mainnet-beta
Rent per byte-year: 0.00000348 SOL
Rent per epoch: 0.000002439 SOL
Rent-exempt minimum: 0.00089088 SOL

eclipse

$ solana rent 0 -u https://mainnetbeta-rpc.eclipse.xyz
Rent per byte-year: 0.000000034 SOL
Rent per epoch: 0.000000023 SOL
Rent-exempt minimum: 0.000008704 SOL