Function: deployToSpark(uint256 deployAmt)

This function moves undeployed USDT owned by the vault into the SparkLend market during the Yield phase. The admin can deploy a specific amount or pass 0 to sweep the entire idle balance, after which the pool pulls the funds using the preset allowance.

Inputs

• deployAmt

  • Control: N/A.

  • Constraints: Must be 0 or less than the outstanding deployable balance (totalSupply - usdtDeployed).

  • Impact: Amount of USDT to deploy to SparkLend.

Branches and code coverage

Intended branches

• Reverts if all shares are already accounted for in usdtDeployed.

  Test coverage

• Passing deployAmt == 0 sweeps the entire deployable amount into Spark.

  Test coverage

• Reverts if providing an explicit amount larger than deployable.

  Test coverage

Negative behavior

• Non-admin callers or calls outside the Yield phase revert.

  Negative test

• Reentrancy is blocked by nonReentrant.

  Negative test

Function call analysis

• SPARK_LEND_USDT_POOL.supply(asset: address(USDT), amount: deployAmt, onBehalfOf: address(this), referralCode: SPARK_REFERRAL_CODE)

  • What is controllable? The admin influences deployAmt — asset, receiver, and referral code are fixed constants determined at deployment.

  • If the return value is controllable, how is it used and how can it go wrong? N/A.

  • What happens if it reverts, reenters or does other unusual control flow? The pool could theoretically call back via ERC-20 hooks, but ReentrancyGuard blocks reentry into vault functions.