# Configurable params

Runtime constants
- can be covered with integration tests, as they are fixed in compile time.
- will need to check to make sure integration tests covered these params

Pallet storage parameters
- Make them bounded: `min`, `max`, `maxChangeAbs`
- To limit maximum, minimum value, and maximum change on each update.
- Similar to `BoundedVec`, bounds are defined as runtime types. Define more new bounded types if needed.

Example:

struct BoundedRate<Range, MaxChangeAbs> {
    rate: Rate,
    _phantom: PhantomData<(Range, MaxChangeAbs)>,
};

enum Error {
    BelowMin,
    AboveMax,
    ExceedMaxChangeAbs,
};

impl<Range: Get<(Rate, Rate)>, MaxChangeAbs: Get<Rate>> BoundedRate<Range, MaxChangeAbs> {
    fn set_rate(new: Rate) -> Result<(), Error> {
        // check limits
        // ...
    }
}

type FractionalRate = BoundedRate<Get<(Zero, One)>, OneFifth>;

// pallet storage
pub type Param<T> = StorageValue<_, FractionalRate>;

## Pallet storage params

CDP engine
- `set_collateral_params`: `Rate`, `Balance`

homa
- `update_homa_params`: `Rate`, `Balance`
- `update_bump_era_params`: `T::BlockNumber`

incentives
- `update_incentive_rewards`: `Balance`
- (deprecated) `update_dex_saving_rewards`
- `update_claim_reward_deduction_rates`: `Rate`