[Documentation]: Simulator parameter file example

[fmorency]

Summary

I would love to see an example of a complete parameter file with both module and simulation parameters. I can change the simulation weights, as described in https://github.com/cosmos/cosmos-sdk/blob/d426a5db677506a981cb094249bb6eaaf6324d39/simapp/params/doc.go, but not module parameters, e.g., mint.params.bond_denom

[fmorency]

I was able to set some module parameters, e.g.

{
  "op_weight_msg_delegate": 0,
  "op_weight_msg_undelegate": 0,
  "op_weight_msg_begin_redelegate": 0,
  "op_weight_msg_cancel_unbonding_delegation": 0,
  "op_weight_msg_create_validator": 0,
  "op_weight_msg_edit_validator": 0,

  "inflation": "0.000000000000000000",
  "annual_provisions": "0.000000000000000000",
  "inflation_rate_change": "0.000000000000000000",
  "inflation_max": "0.000000000000000000",
  "inflation_min": "0.000000000000000000",
  "goal_bonded": "0.670000000000000000",
  "blocks_per_year": "6311520",

  "slash_fraction_double_sign": "0.000000000000000000",
  "slash_fraction_downtime": "0.000000000000000000",

  "community_tax": "0.0",
}

but some other parameters can't be set because they are hardcoded in the simulator, e.g.,

mint_denom

cosmos-sdk/x/mint/simulation/genesis.go

Line 67 in cc1267b

mintDenom := simState.BondDenom

bond_denom

cosmos-sdk/x/staking/simulation/genesis.go

Line 67 in cc1267b

params := types.NewParams(simState.UnbondTime, maxVals, 7, simState.BondDenom, minCommissionRate, rotationFee)

where BondDenom = sdk.DefaultBondDenom

The way the parameter file is handled can also lead to key collisions as nothing prevents module X from defining the same key as module Y. I was bitten by this.