Merge PR #5240: x/evidence module implementation

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)

docs/building-modules/README.md

@@ -1,78 +1,75 @@
-# Auth 
+# Modules
+
+## Auth
 
 The `x/auth` modules is used for accounts
 
-See the [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/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)
 
-See the [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).
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/bank)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/bank)
 
-See the [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)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/slashing)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/slashing)
 
-See the
-[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)
+- [API docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/distribution)
+- [Specification](https://github.com/cosmos/cosmos-sdk/tree/master/docs/spec/distribution)
 
-See the
-[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)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/crisis)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/crisis)
 
-See the [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)
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/mint)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/mint)
 
-See the [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)
 
-See the [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.
+
+- [API Docs](https://godoc.org/github.com/cosmos/cosmos-sdk/x/evidence)
+- [Specification](https://github.com/cosmos/cosmos-sdk/blob/master/docs/spec/evidence)