cosmos · alexanderbez · Nov 6, 2019 · Oct 24, 2019 · Oct 24, 2019 · Oct 24, 2019
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -81,6 +81,7 @@ increased significantly due to modular `AnteHandler` support. Increase GasLimit
 
 ### Features
 
+* (x/evidence) [\#5240](https://github.com/cosmos/cosmos-sdk/pull/5240) Initial implementation of the `x/evidence` module.
 * (cli) [\#5212](https://github.com/cosmos/cosmos-sdk/issues/5212) The `q gov proposals` command now supports pagination.
 * (store) [\#4724](https://github.com/cosmos/cosmos-sdk/issues/4724) Multistore supports substore migrations upon load. New `rootmulti.Store.LoadLatestVersionAndUpgrade` method in
 `Baseapp` supports `StoreLoader` to enable various upgrade strategies. It no

diff --git a/docs/architecture/adr-009-evidence-module.md b/docs/architecture/adr-009-evidence-module.md
@@ -3,10 +3,11 @@
 ## Changelog
 
 - 2019 July 31: Initial draft
+- 2019 October 24: Initial implementation
 
 ## Status
 
-Proposed
+Accepted
 
 ## Context
 
@@ -55,7 +56,8 @@ type Evidence interface {
   Route() string
   Type() string
   String() string
-  ValidateBasic() Error
+  Hash() HexBytes
+  ValidateBasic() error
 
   // The consensus address of the malicious validator at time of infraction
   GetConsensusAddress() ConsAddress
@@ -78,7 +80,7 @@ the `x/evidence` module. It accomplishes this through the `Router` implementatio
 
 ```go
 type Router interface {
-  AddRoute(r string, h Handler)
+  AddRoute(r string, h Handler) Router
   HasRoute(r string) bool
   GetRoute(path string) Handler
   Seal()
@@ -97,7 +99,7 @@ necessary in order for the `Handler` to make the necessary state transitions.
 If no error is returned, the `Evidence` is considered valid.
 
 ```go
-type Handler func(Context, Evidence) Error
+type Handler func(Context, Evidence) error
 ```
 
 ### Submission
@@ -128,7 +130,7 @@ the module's router and invoking the corresponding `Handler` which may include
 slashing and jailing the validator. Upon success, the submitted evidence is persisted.
 
 ```go
-func (k Keeper) SubmitEvidence(ctx Context, evidence Evidence) Error {
+func (k Keeper) SubmitEvidence(ctx Context, evidence Evidence) error {
   handler := keeper.router.GetRoute(evidence.Route())
   if err := handler(ctx, evidence); err != nil {
     return ErrInvalidEvidence(keeper.codespace, err)
@@ -177,3 +179,4 @@ due to the inability to introduce the new evidence type's corresponding handler
 
 - [ICS](https://github.com/cosmos/ics)
 - [IBC Architecture](https://github.com/cosmos/ics/blob/master/ibc/1_IBC_ARCHITECTURE.md)
+- [Tendermint Fork Accountability](https://github.com/tendermint/tendermint/blob/master/docs/spec/consensus/fork-accountability.md)
diff --git a/docs/building-modules/README.md b/docs/building-modules/README.md
@@ -1,78 +1,75 @@
-# Auth 
+# Modules
 
-The `x/auth` modules is used for accounts
+## Auth
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/auth)
+The `x/auth` modules is used for accounts
 
-See the [specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/auth)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/auth)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/auth)
 
-# Bank
+## Bank
 
 The `x/bank` module is for transferring coins between accounts.
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/bank).
-
-See the [specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/bank)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/bank)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/bank)
 
-# Stake
+## Staking
 
 The `x/staking` module is for Cosmos Delegated-Proof-of-Stake.
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/staking).
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/staking)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/staking)
 
-See the
-[specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/staking)
-
-# Slashing
+## Slashing
 
 The `x/slashing` module is for Cosmos Delegated-Proof-of-Stake.
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/slashing)
-
-See the
-[specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/slashing)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/slashing)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/slashing)
 
-# Distribution
+## Distribution
 
 The `x/distribution` module is for distributing fees and inflation across bonded
 stakeholders.
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/distribution)
-
-See the
-[specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/distribution)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/distribution)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/distribution)
 
-# Governance
+## Governance
 
 The `x/gov` module is for bonded stakeholders to make proposals and vote on them.
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/gov)
-
-See the
-[specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/governance)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/gov)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/governance)
 
 To keep up with the current status of IBC, follow and contribute to [ICS](https://github.com/cosmos/ics)
 
-# Crisis
+## Crisis
 
 The `x/crisis` module is for halting the blockchain under certain circumstances.
 
-See the [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/crisis)
-
-See the [specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/crisis)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/crisis)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/crisis)
 
-# Mint
+## Mint
 
 The `x/mint` module is for flexible inflation rates and effect a balance between market liquidity and staked supply.
 
-See the [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/mint)
-
-See the [specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/mint)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/mint)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/mint)
 
-# Params
+## Params
 
 The `x/params` module provides a globally available parameter store.
 
-See the [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/params)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/params)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/params)
+
+## Evidence
+
+The `x/evidence` modules provides a mechanism for defining and submitting arbitrary
+events of misbehavior and a means to execute custom business logic for such misbehavior.
 
-See the [specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/params)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/evidence)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/evidence)
diff --git a/simapp/app.go b/simapp/app.go
@@ -20,6 +20,7 @@ import (
 	"github.com/cosmos/cosmos-sdk/x/bank"
 	"github.com/cosmos/cosmos-sdk/x/crisis"
 	distr "github.com/cosmos/cosmos-sdk/x/distribution"
+	"github.com/cosmos/cosmos-sdk/x/evidence"
 	"github.com/cosmos/cosmos-sdk/x/genutil"
 	"github.com/cosmos/cosmos-sdk/x/gov"
 	"github.com/cosmos/cosmos-sdk/x/mint"
@@ -54,6 +55,7 @@ var (
 		params.AppModuleBasic{},
 		crisis.AppModuleBasic{},
 		slashing.AppModuleBasic{},
+		evidence.AppModuleBasic{},
 	)
 
 	// module account permissions
@@ -90,6 +92,9 @@ type SimApp struct {
 	keys  map[string]*sdk.KVStoreKey
 	tkeys map[string]*sdk.TransientStoreKey
 
+	// subspaces
+	subspaces map[string]params.Subspace
+
 	// keepers
 	AccountKeeper  auth.AccountKeeper
 	BankKeeper     bank.Keeper
@@ -101,6 +106,7 @@ type SimApp struct {
 	GovKeeper      gov.Keeper
 	CrisisKeeper   crisis.Keeper
 	ParamsKeeper   params.Keeper
+	EvidenceKeeper evidence.Keeper
 
 	// the module manager
 	mm *module.Manager
@@ -121,9 +127,10 @@ func NewSimApp(
 	bApp.SetCommitMultiStoreTracer(traceStore)
 	bApp.SetAppVersion(version.Version)
 
-	keys := sdk.NewKVStoreKeys(bam.MainStoreKey, auth.StoreKey, staking.StoreKey,
-		supply.StoreKey, mint.StoreKey, distr.StoreKey, slashing.StoreKey,
-		gov.StoreKey, params.StoreKey)
+	keys := sdk.NewKVStoreKeys(
+		bam.MainStoreKey, auth.StoreKey, staking.StoreKey, supply.StoreKey, mint.StoreKey,
+		distr.StoreKey, slashing.StoreKey, gov.StoreKey, params.StoreKey, evidence.StoreKey,
+	)
 	tkeys := sdk.NewTransientStoreKeys(params.TStoreKey)
 
 	app := &SimApp{
@@ -132,39 +139,68 @@ func NewSimApp(
 		invCheckPeriod: invCheckPeriod,
 		keys:           keys,
 		tkeys:          tkeys,
+		subspaces:      make(map[string]params.Subspace),
 	}
 
 	// init params keeper and subspaces
 	app.ParamsKeeper = params.NewKeeper(app.cdc, keys[params.StoreKey], tkeys[params.TStoreKey], params.DefaultCodespace)
-	authSubspace := app.ParamsKeeper.Subspace(auth.DefaultParamspace)
-	bankSubspace := app.ParamsKeeper.Subspace(bank.DefaultParamspace)
-	stakingSubspace := app.ParamsKeeper.Subspace(staking.DefaultParamspace)
-	mintSubspace := app.ParamsKeeper.Subspace(mint.DefaultParamspace)
-	distrSubspace := app.ParamsKeeper.Subspace(distr.DefaultParamspace)
-	slashingSubspace := app.ParamsKeeper.Subspace(slashing.DefaultParamspace)
-	govSubspace := app.ParamsKeeper.Subspace(gov.DefaultParamspace).WithKeyTable(gov.ParamKeyTable())
-	crisisSubspace := app.ParamsKeeper.Subspace(crisis.DefaultParamspace)
+	app.subspaces[auth.ModuleName] = app.ParamsKeeper.Subspace(auth.DefaultParamspace)
+	app.subspaces[bank.ModuleName] = app.ParamsKeeper.Subspace(bank.DefaultParamspace)
+	app.subspaces[staking.ModuleName] = app.ParamsKeeper.Subspace(staking.DefaultParamspace)
+	app.subspaces[mint.ModuleName] = app.ParamsKeeper.Subspace(mint.DefaultParamspace)
+	app.subspaces[distr.ModuleName] = app.ParamsKeeper.Subspace(distr.DefaultParamspace)
+	app.subspaces[slashing.ModuleName] = app.ParamsKeeper.Subspace(slashing.DefaultParamspace)
+	app.subspaces[gov.ModuleName] = app.ParamsKeeper.Subspace(gov.DefaultParamspace).WithKeyTable(gov.ParamKeyTable())
+	app.subspaces[crisis.ModuleName] = app.ParamsKeeper.Subspace(crisis.DefaultParamspace)
+	app.subspaces[evidence.ModuleName] = app.ParamsKeeper.Subspace(evidence.DefaultParamspace)
 
 	// add keepers
-	app.AccountKeeper = auth.NewAccountKeeper(app.cdc, keys[auth.StoreKey], authSubspace, auth.ProtoBaseAccount)
-	app.BankKeeper = bank.NewBaseKeeper(app.AccountKeeper, bankSubspace, bank.DefaultCodespace, app.ModuleAccountAddrs())
-	app.SupplyKeeper = supply.NewKeeper(app.cdc, keys[supply.StoreKey], app.AccountKeeper, app.BankKeeper, maccPerms)
-	stakingKeeper := staking.NewKeeper(app.cdc, keys[staking.StoreKey],
-		app.SupplyKeeper, stakingSubspace, staking.DefaultCodespace)
-	app.MintKeeper = mint.NewKeeper(app.cdc, keys[mint.StoreKey], mintSubspace, &stakingKeeper, app.SupplyKeeper, auth.FeeCollectorName)
-	app.DistrKeeper = distr.NewKeeper(app.cdc, keys[distr.StoreKey], distrSubspace, &stakingKeeper,
-		app.SupplyKeeper, distr.DefaultCodespace, auth.FeeCollectorName, app.ModuleAccountAddrs())
-	app.SlashingKeeper = slashing.NewKeeper(app.cdc, keys[slashing.StoreKey], &stakingKeeper,
-		slashingSubspace, slashing.DefaultCodespace)
-	app.CrisisKeeper = crisis.NewKeeper(crisisSubspace, invCheckPeriod, app.SupplyKeeper, auth.FeeCollectorName)
+	app.AccountKeeper = auth.NewAccountKeeper(
+		app.cdc, keys[auth.StoreKey], app.subspaces[auth.ModuleName], auth.ProtoBaseAccount,
+	)
+	app.BankKeeper = bank.NewBaseKeeper(
+		app.AccountKeeper, app.subspaces[bank.ModuleName], bank.DefaultCodespace,
+		app.ModuleAccountAddrs(),
+	)
+	app.SupplyKeeper = supply.NewKeeper(
+		app.cdc, keys[supply.StoreKey], app.AccountKeeper, app.BankKeeper, maccPerms,
+	)
+	stakingKeeper := staking.NewKeeper(
+		app.cdc, keys[staking.StoreKey], app.SupplyKeeper, app.subspaces[staking.ModuleName],
+		staking.DefaultCodespace)
+	app.MintKeeper = mint.NewKeeper(
+		app.cdc, keys[mint.StoreKey], app.subspaces[mint.ModuleName], &stakingKeeper,
+		app.SupplyKeeper, auth.FeeCollectorName,
+	)
+	app.DistrKeeper = distr.NewKeeper(
+		app.cdc, keys[distr.StoreKey], app.subspaces[distr.ModuleName], &stakingKeeper,
+		app.SupplyKeeper, distr.DefaultCodespace, auth.FeeCollectorName, app.ModuleAccountAddrs(),
+	)
+	app.SlashingKeeper = slashing.NewKeeper(
+		app.cdc, keys[slashing.StoreKey], &stakingKeeper, app.subspaces[slashing.ModuleName], slashing.DefaultCodespace,
+	)
+	app.CrisisKeeper = crisis.NewKeeper(
+		app.subspaces[crisis.ModuleName], invCheckPeriod, app.SupplyKeeper, auth.FeeCollectorName,
+	)
+
+	// create evidence keeper with router
+	evidenceKeeper := evidence.NewKeeper(
+		app.cdc, keys[evidence.StoreKey], app.subspaces[evidence.ModuleName], evidence.DefaultCodespace,
+	)
+	evidenceRouter := evidence.NewRouter()
+	// TODO: Register evidence routes.
+	evidenceKeeper.SetRouter(evidenceRouter)
+	app.EvidenceKeeper = *evidenceKeeper
 
 	// register the proposal types
 	govRouter := gov.NewRouter()
 	govRouter.AddRoute(gov.RouterKey, gov.ProposalHandler).
 		AddRoute(params.RouterKey, params.NewParamChangeProposalHandler(app.ParamsKeeper)).
 		AddRoute(distr.RouterKey, distr.NewCommunityPoolSpendProposalHandler(app.DistrKeeper))
-	app.GovKeeper = gov.NewKeeper(app.cdc, keys[gov.StoreKey], govSubspace,
-		app.SupplyKeeper, &stakingKeeper, gov.DefaultCodespace, govRouter)
+	app.GovKeeper = gov.NewKeeper(
+		app.cdc, keys[gov.StoreKey], app.subspaces[gov.ModuleName], app.SupplyKeeper,
+		&stakingKeeper, gov.DefaultCodespace, govRouter,
+	)
 
 	// register the staking hooks
 	// NOTE: stakingKeeper above is passed by reference, so that it will contain these hooks
@@ -185,22 +221,21 @@ func NewSimApp(
 		distr.NewAppModule(app.DistrKeeper, app.SupplyKeeper),
 		slashing.NewAppModule(app.SlashingKeeper, app.StakingKeeper),
 		staking.NewAppModule(app.StakingKeeper, app.AccountKeeper, app.SupplyKeeper),
+		evidence.NewAppModule(app.EvidenceKeeper),
 	)
 
 	// During begin block slashing happens after distr.BeginBlocker so that
 	// there is nothing left over in the validator fee pool, so as to keep the
 	// CanWithdrawInvariant invariant.
 	app.mm.SetOrderBeginBlockers(mint.ModuleName, distr.ModuleName, slashing.ModuleName)
-
 	app.mm.SetOrderEndBlockers(crisis.ModuleName, gov.ModuleName, staking.ModuleName)
 
 	// NOTE: The genutils moodule must occur after staking so that pools are
 	// properly initialized with tokens from genesis accounts.
 	app.mm.SetOrderInitGenesis(
-		auth.ModuleName, distr.ModuleName, staking.ModuleName,
-		bank.ModuleName, slashing.ModuleName, gov.ModuleName,
-		mint.ModuleName, supply.ModuleName, crisis.ModuleName,
-		genutil.ModuleName,
+		auth.ModuleName, distr.ModuleName, staking.ModuleName, bank.ModuleName,
+		slashing.ModuleName, gov.ModuleName, mint.ModuleName, supply.ModuleName,
+		crisis.ModuleName, genutil.ModuleName, evidence.ModuleName,
 	)
 
 	app.mm.RegisterInvariants(&app.CrisisKeeper)
@@ -239,6 +274,7 @@ func NewSimApp(
 			cmn.Exit(err.Error())
 		}
 	}
+
 	return app
 }
 
@@ -274,21 +310,35 @@ func (app *SimApp) ModuleAccountAddrs() map[string]bool {
 	return modAccAddrs
 }
 
-// Codec returns simapp's codec
+// Codec returns SimApp's codec.
+//
+// NOTE: This is solely to be used for testing purposes as it may be desirable
+// for modules to register their own custom testing types.
 func (app *SimApp) Codec() *codec.Codec {
 	return app.cdc
 }
 
-// GetKey returns the KVStoreKey for the provided store key
+// GetKey returns the KVStoreKey for the provided store key.
+//
+// NOTE: This is solely to be used for testing purposes.
 func (app *SimApp) GetKey(storeKey string) *sdk.KVStoreKey {
 	return app.keys[storeKey]
 }
 
-// GetTKey returns the TransientStoreKey for the provided store key
+// GetTKey returns the TransientStoreKey for the provided store key.
+//
+// NOTE: This is solely to be used for testing purposes.
 func (app *SimApp) GetTKey(storeKey string) *sdk.TransientStoreKey {
 	return app.tkeys[storeKey]
 }
 
+// GetSubspace returns a param subspace for a given module name.
+//
+// NOTE: This is solely to be used for testing purposes.
+func (app *SimApp) GetSubspace(moduleName string) params.Subspace {
+	return app.subspaces[moduleName]
+}
+
 // GetMaccPerms returns a copy of the module account permissions
 func GetMaccPerms() map[string][]string {
 	dupMaccPerms := make(map[string][]string)