rpc: /block_results fix docs + write test + restructure response (#3615)

BREAKING

Example response:

```json
{
  "jsonrpc": "2.0",
  "id": "",
  "result": {
    "height": "2109",
    "txs_results": null,
    "begin_block_events": null,
    "end_block_events": null,
    "validator_updates": null,
    "consensus_param_updates": null
  }
}
```

Old result consisted of ABCIResponses struct and height. Exposing
internal ABCI structures (which we store in state package) in RPC seems
bad to me for the following reasons:

1) high risk of breaking the API when somebody changes internal structs
(HAPPENED HERE!)
2) RPC is aware of ABCI, which I'm not sure we want

state/execution.go

@@ -138,7 +138,7 @@ func (blockExec *BlockExecutor) ApplyBlock(state State, blockID types.BlockID, b
 	fail.Fail() // XXX
 
 	// Save the results before we commit.
-	saveABCIResponses(blockExec.db, block.Height, abciResponses)
+	SaveABCIResponses(blockExec.db, block.Height, abciResponses)
 
 	fail.Fail() // XXX
 
@@ -163,7 +163,7 @@ func (blockExec *BlockExecutor) ApplyBlock(state State, blockID types.BlockID, b
 	}
 
 	// Lock mempool, commit app state, update mempoool.
-	appHash, err := blockExec.Commit(state, block, abciResponses.DeliverTx)
+	appHash, err := blockExec.Commit(state, block, abciResponses.DeliverTxs)
 	if err != nil {
 		return state, fmt.Errorf("Commit failed for application: %v", err)
 	}
@@ -267,7 +267,7 @@ func execBlockOnProxyApp(
 				logger.Debug("Invalid tx", "code", txRes.Code, "log", txRes.Log)
 				invalidTxs++
 			}
-			abciResponses.DeliverTx[txIndex] = txRes
+			abciResponses.DeliverTxs[txIndex] = txRes
 			txIndex++
 		}
 	}
@@ -475,7 +475,7 @@ func fireEvents(
 			Height: block.Height,
 			Index:  uint32(i),
 			Tx:     tx,
-			Result: *(abciResponses.DeliverTx[i]),
+			Result: *(abciResponses.DeliverTxs[i]),
 		}})
 	}
 

state/export_test.go

@@ -43,12 +43,6 @@ func CalcValidatorsKey(height int64) []byte {
 	return calcValidatorsKey(height)
 }
 
-// SaveABCIResponses is an alias for the private saveABCIResponses method in
-// store.go, exported exclusively and explicitly for testing.
-func SaveABCIResponses(db dbm.DB, height int64, abciResponses *ABCIResponses) {
-	saveABCIResponses(db, height, abciResponses)
-}
-
 // SaveConsensusParamsInfo is an alias for the private saveConsensusParamsInfo
 // method in store.go, exported exclusively and explicitly for testing.
 func SaveConsensusParamsInfo(db dbm.DB, nextHeight, changeHeight int64, params types.ConsensusParams) {

state/state_test.go

@@ -89,8 +89,8 @@ func TestABCIResponsesSaveLoad1(t *testing.T) {
 	// Build mock responses.
 	block := makeBlock(state, 2)
 	abciResponses := sm.NewABCIResponses(block)
-	abciResponses.DeliverTx[0] = &abci.ResponseDeliverTx{Data: []byte("foo"), Events: nil}
-	abciResponses.DeliverTx[1] = &abci.ResponseDeliverTx{Data: []byte("bar"), Log: "ok", Events: nil}
+	abciResponses.DeliverTxs[0] = &abci.ResponseDeliverTx{Data: []byte("foo"), Events: nil}
+	abciResponses.DeliverTxs[1] = &abci.ResponseDeliverTx{Data: []byte("bar"), Log: "ok", Events: nil}
 	abciResponses.EndBlock = &abci.ResponseEndBlock{ValidatorUpdates: []abci.ValidatorUpdate{
 		types.TM2PB.NewValidatorUpdate(ed25519.GenPrivKey().PubKey(), 10),
 	}}
@@ -158,7 +158,7 @@ func TestABCIResponsesSaveLoad2(t *testing.T) {
 	for i, tc := range cases {
 		h := int64(i + 1) // last block height, one below what we save
 		responses := &sm.ABCIResponses{
-			DeliverTx: tc.added,
+			DeliverTxs: tc.added,
 			EndBlock:  &abci.ResponseEndBlock{},
 		}
 		sm.SaveABCIResponses(stateDB, h, responses)

state/store.go

@@ -115,7 +115,7 @@ func saveState(db dbm.DB, state State, key []byte) {
 // of the various ABCI calls during block processing.
 // It is persisted to disk for each height before calling Commit.
 type ABCIResponses struct {
-	DeliverTx  []*abci.ResponseDeliverTx `json:"deliver_tx"`
+	DeliverTxs []*abci.ResponseDeliverTx `json:"deliver_txs"`
 	EndBlock   *abci.ResponseEndBlock    `json:"end_block"`
 	BeginBlock *abci.ResponseBeginBlock  `json:"begin_block"`
 }
@@ -128,7 +128,7 @@ func NewABCIResponses(block *types.Block) *ABCIResponses {
 		resDeliverTxs = nil
 	}
 	return &ABCIResponses{
-		DeliverTx: resDeliverTxs,
+		DeliverTxs: resDeliverTxs,
 	}
 }
 
@@ -138,7 +138,7 @@ func (arz *ABCIResponses) Bytes() []byte {
 }
 
 func (arz *ABCIResponses) ResultsHash() []byte {
-	results := types.NewResults(arz.DeliverTx)
+	results := types.NewResults(arz.DeliverTxs)
 	return results.Hash()
 }
 
@@ -165,8 +165,11 @@ func LoadABCIResponses(db dbm.DB, height int64) (*ABCIResponses, error) {
 
 // SaveABCIResponses persists the ABCIResponses to the database.
 // This is useful in case we crash after app.Commit and before s.Save().
-// Responses are indexed by height so they can also be loaded later to produce Merkle proofs.
-func saveABCIResponses(db dbm.DB, height int64, abciResponses *ABCIResponses) {
+// Responses are indexed by height so they can also be loaded later to produce
+// Merkle proofs.
+//
+// Exposed for testing.
+func SaveABCIResponses(db dbm.DB, height int64, abciResponses *ABCIResponses) {
 	db.SetSync(calcABCIResponsesKey(height), abciResponses.Bytes())
 }