revert 8909

[colin-axner]

Description

reverts: #8909

I would like to do the fix in types/module/module.go:

// InitGenesis performs init genesis functionality for modules
+// InitGenesis performs init genesis functionality for modules. Exactly one
+// module must return a non-empty validator set update to correctly initialize
+// the chain.
 func (m *Manager) InitGenesis(ctx sdk.Context, cdc codec.JSONMarshaler, genesisData map[string]json.RawMessage) abci.ResponseInitChain {
        var validatorUpdates []abci.ValidatorUpdate
        for _, moduleName := range m.OrderInitGenesis {
@@ -315,6 +318,11 @@ func (m *Manager) InitGenesis(ctx sdk.Context, cdc codec.JSONMarshaler, genesisD
                }
        }
 
+       // a chain must initialize with a non-empty validator set
+       if len(validatorUpdates) == 0 {
+               panic(fmt.Sprintf("validator set is empty after InitGenesis, please ensure at least one validator is initialized with a delegation greater than or equal to the PowerReduction (%d)", sdk.PowerReduction))
+       }
+
        return abci.ResponseInitChain{
                Validators: validatorUpdates,
        }

But this breaks simapp. Specifically the default simapp runs without a validator set and it uses InitGenesis. I'd like either someone from the SDK to take over this issue or to give me an ACK on switching default simapp setup to initialize with a single validator. I ran into this issue several months ago when creating the ibc testing package, so I already have done most of the heavy lifting.

We would need to add this into the Setup function of simapp:

// generate validator private/public key
	privVal := mock.NewPV()
	pubKey, err := privVal.GetPubKey()
	require.NoError(t, err)

	// create validator set with single validator
	validator := tmtypes.NewValidator(pubKey, 1)
	valSet := tmtypes.NewValidatorSet([]*tmtypes.Validator{validator})
	signers := []tmtypes.PrivValidator{privVal}

	// generate genesis account
	senderPrivKey := secp256k1.GenPrivKey()
	acc := authtypes.NewBaseAccount(senderPrivKey.PubKey().Address().Bytes(), senderPrivKey.PubKey(), 0, 0)
	balance := banktypes.Balance{
		Address: acc.GetAddress().String(),
		Coins:   sdk.NewCoins(sdk.NewCoin(sdk.DefaultBondDenom, sdk.NewInt(100000000000000))),
	}

	app := simapp.SetupWithGenesisValSet(t, valSet, []authtypes.GenesisAccount{acc}, balance)

NOTE: mock is a package in ibc-go which mocks a simple tendermint validator. It is very straightforward and we could port it over to the SDK

I did a quick check locally to see how troublesome this change is, and several tests either:

• rely on empty validator set (looks like query functions?)
• attempt to do their own initialize (not via Setup)

Anyone have any thoughts? We can merge the revert for now and move all this into an issue

closes: #XXXX

---

Before we can merge this PR, please make sure that all the following items have been
checked off. If any of the checklist items are not applicable, please leave them but
write a little note why.

• Targeted PR against correct branch (see CONTRIBUTING.md)
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work.
• Code follows the module structure standards.
• Wrote unit and integration tests
• Updated relevant documentation (docs/) or specification (x/<module>/spec/)
• Added relevant godoc comments.
• Added a relevant changelog entry to the Unreleased section in CHANGELOG.md
• Re-reviewed Files changed in the Github PR explorer
• Review Codecov Report in the comment section below once CI passes

[colin-axner]

opened #8961

[codecov]

Codecov Report

Merging #8960 (9577865) into master (2ebf79f) will decrease coverage by 0.11%.
The diff coverage is 100.00%.

❗ Current head 9577865 differs from pull request most recent head 81c3ef0. Consider uploading reports for the commit 81c3ef0 to get more accurate results

@@            Coverage Diff             @@
##           master    #8960      +/-   ##
==========================================
- Coverage   58.99%   58.87%   -0.12%     
==========================================
  Files         575      571       -4     
  Lines       32198    32108      -90     
==========================================
- Hits        18996    18905      -91     
+ Misses      10985    10982       -3     
- Partials     2217     2221       +4     

Impacted Files	Coverage Δ
x/staking/types/msg.go	54.92% <ø> (-0.63%)	⬇️
x/staking/simulation/operations.go	73.46% <100.00%> (+0.29%)	⬆️
x/auth/tx/sigs.go	53.75% <0.00%> (-23.75%)	⬇️
store/mem/store.go	60.00% <0.00%> (-21.82%)	⬇️
codec/json.go	50.00% <0.00%> (-10.00%)	⬇️
store/dbadapter/store.go	91.66% <0.00%> (-8.34%)	⬇️
client/keys/utils.go	38.88% <0.00%> (-3.97%)	⬇️
x/bank/keeper/keeper.go	72.91% <0.00%> (-3.81%)	⬇️
x/auth/vesting/types/vesting_account.go	85.36% <0.00%> (-3.47%)	⬇️
types/module/configurator.go	15.38% <0.00%> (-3.14%)	⬇️
... and 59 more

[orijbot]

Benchmark beginning. Status page: https://github.orijtech.com/benchmark/status?commit=183267f850f6e546396b97149d7f1f1d652be5fa

[amaury1093]

@colin-axner could you fix the conflicts? Okay to automerge right after