baseapp: add sdk.Result to simulation response

CHANGELOG.md

@@ -70,6 +70,8 @@ to now accept a `codec.JSONMarshaler` for modular serialization of genesis state
 * (crypto/keys) [\#5735](https://github.com/cosmos/cosmos-sdk/pull/5735) Keyring's Update() function is now no-op.
 * (types/rest) [\#5779](https://github.com/cosmos/cosmos-sdk/pull/5779) Drop unused Parse{Int64OrReturnBadRequest,QueryParamBool}() functions.
 * (keys) [\#5820](https://github.com/cosmos/cosmos-sdk/pull/5820/) Removed method CloseDB from Keybase interface.
+* (baseapp) [\#5837](https://github.com/cosmos/cosmos-sdk/issues/5837) Transaction simulation now returns a `SimulationResponse` which contains the `GasInfo` and
+`Result` from the execution.
 
 ### Features
 

baseapp/abci.go

@@ -326,12 +326,20 @@ func handleQueryApp(app *BaseApp, path []string, req abci.RequestQuery) abci.Res
 				return sdkerrors.QueryResult(sdkerrors.Wrap(err, "failed to decode tx"))
 			}
 
-			gInfo, _, _ := app.Simulate(txBytes, tx)
+			gInfo, res, err := app.Simulate(txBytes, tx)
+			if err != nil {
+				return sdkerrors.QueryResult(sdkerrors.Wrap(err, "failed to simulate tx"))
+			}
+
+			simRes := sdk.SimulationResponse{
+				GasInfo: gInfo,
+				Result:  res,
+			}
 
 			return abci.ResponseQuery{
 				Codespace: sdkerrors.RootCodespace,
 				Height:    req.Height,
-				Value:     codec.Cdc.MustMarshalBinaryBare(gInfo.GasUsed),
+				Value:     codec.Cdc.MustMarshalBinaryBare(simRes),
 			}
 
 		case "version":

baseapp/baseapp_test.go

@@ -935,10 +935,13 @@ func TestSimulateTx(t *testing.T) {
 		queryResult := app.Query(query)
 		require.True(t, queryResult.IsOK(), queryResult.Log)
 
-		var res uint64
-		err = codec.Cdc.UnmarshalBinaryBare(queryResult.Value, &res)
+		var simRes sdk.SimulationResponse
+		err = codec.Cdc.UnmarshalBinaryBare(queryResult.Value, &simRes)
 		require.NoError(t, err)
-		require.Equal(t, gasConsumed, res)
+		require.Equal(t, gInfo, simRes.GasInfo)
+		require.Equal(t, result.Log, simRes.Result.Log)
+		require.Equal(t, result.Events, simRes.Result.Events)
+		require.True(t, bytes.Equal(result.Data, simRes.Result.Data))
 		app.EndBlock(abci.RequestEndBlock{})
 		app.Commit()
 	}

types/result.go

@@ -17,7 +17,7 @@ type GasInfo struct {
 	// GasWanted is the maximum units of work we allow this tx to perform.
 	GasWanted uint64
 
-	// GasUsed is the amount of gas actually consumed. NOTE: unimplemented
+	// GasUsed is the amount of gas actually consumed.
 	GasUsed uint64
 }
 
@@ -35,6 +35,13 @@ type Result struct {
 	Events Events
 }
 
+// SimulationResponse defines the response generated when a transaction is successfully
+// simulated by the Baseapp.
+type SimulationResponse struct {
+	GasInfo
+	Result *Result
+}
+
 // ABCIMessageLogs represents a slice of ABCIMessageLog.
 type ABCIMessageLogs []ABCIMessageLog