function purchaseBond(uint256 id_, uint256 amount_, uint256 minAmountOut_ ) external

1. Intended behavior.

   • Exchange quote tokens for a bond in a specified market

2. Negative behavior.

   • Should only be callable by the BondBaseTeller inheriting contract, revert otherwise (this check is put in place)

   • Shouldn’t allow the purchase of bonds from ids that have no registered market

   • Should disallow the purchase if the amount of bonds is less than the minAmountOut (this check is put in place) #slippagecheck

3. Preconditions.

   • Assumes that a teller is working properly and that the msg.sender is the teller in the cause.

   • Assumes that the market exists (through its id) and that it’s not closed

   • Also, the check on currentTime should be > than term.conclusion since it may close within same block.

4. Postconditions..

   • If maxDebt was reached, the market has to be closed, otherwise, tuned accordingly.

   • market.capacity will decrease based on the amount or payout values.

   • market.purchase += amount_

   • market.sold += payout

5. Inputs.

   • uint256 id_: full control, check that the market[id] has not concluded.

   • uint256 amount_: full control.

   • uint256 minAmountOut_: slippage check, is checked properly.

6. Examine all function calls the function makes.

   a. (price, payout) = decayAndGetPrice(id, amount_, uint48(block.timestamp))

   • What is controllable? (callee, params, return value): id - controllable; amount - controllable - affects the number of payout tokens; block.timestamp - partially controlled

   • If return value is controllable, how is it used and how can it go wrong: price - even if something goes wrong, the price cannot be less than the market.minPrice; payout - if it is calculated incorrectly and the capacity value wasn't set (in a case when it was set for quoteToken) and market.minPrice value wasn’t set properly by the market owner, then it can be possible to steal the owner's funds.

   • What happens if it reverts or tries to reenter: not a problem.