Remove the Minter struct from genesis

[rach-id]

Context

celestia-app/x/mint/keeper/genesis.go

Lines 8 to 16 in 60f9328

	// InitGenesis initializes the x/mint store with data from the genesis state.
	func (k Keeper) InitGenesis(ctx sdk.Context, ak types.AccountKeeper, data *types.GenesisState) {
	k.SetMinter(ctx, data.Minter)
	// override the genesis time with the actual genesis time supplied in `InitChain`
	blockTime := ctx.BlockTime()
	gt := types.GenesisTime{
	GenesisTime: &blockTime,
	}
	k.SetGenesisTime(ctx, gt)

Problem

Currently, the minter struct is exposed in the genesis file:

    "mint": {
      "minter": {
        "inflation_rate": "0.080000000000000000",
        "annual_provisions": "0.000000000000000000",
        "previous_block_time": null,
        "bond_denom": "utia"
      }
    },

None of these fields is not used in the app:

• inflation_rate: Even if a value is set at this level, the inflation rates are hard-coded and these values are not used:
  

  celestia-app/x/mint/abci.go

  Line 29 in 60f9328

  newInflationRate := minter.CalculateInflationRate(ctx, *genesisTime)

• annual_provisions: Also calculated in BeginBlocker in the first block:
  

  celestia-app/x/mint/abci.go

  Line 42 in 60f9328

  minter.AnnualProvisions = newInflationRate.MulInt(totalSupply)

• previous_block_time: Already not specified in genesis

• bond_denom: This parameter is not expected to change at all

Proposal

Remove the Minter struct from genesis.

We could also remove the protobuf definition (To be confirmed) as the Minter struct will only be stored in state, and not written to genesis, or used in tx/queries

[rootulp]

I think we should preserve bond_denom in the genesis for consistency with other modules (i.e. x/staking here, x/gov here). I agree, the other fields should be removed from the genesis file because they are overwritten at block one anyway. Unfortunately, I think this may be a breaking change that is too late to include in the v1.0.0 release because it implies a change to the genesis.json.

[rach-id]

I agree, but concerning this:

Unfortunately, I think this may be a breaking change that is too late to include in the v1.0.0 release because it implies a change to the genesis.json.

Even if we remove those fields from the struct, or even remove the whole Minter struct, the app won't complain if fed a genesis file containing those fields. So we can keep the same genesis while having this issue implemented