REST bank transfers fail due to encoding. (#6536)

Bank module REST endpoint bank/accounts/{addr}/transfers
was returning invalid StdTx format.

CHANGELOG.md

@@ -177,6 +177,8 @@ be used to retrieve the actual proposal `Content`. Also the `NewMsgSubmitProposa
 
 ### Bug Fixes
 
+* (x/bank) [\#6536](https://github.com/cosmos/cosmos-sdk/pull/6536) Fix bug in `WriteGeneratedTxResponse` function used by multiple 
+REST endpoints. Now it writes a Tx in StdTx format.
 * (x/staking) [\#6529](https://github.com/cosmos/cosmos-sdk/pull/6529) Export validator addresses (previously was empty).
 * (export) [\#6510](https://github.com/cosmos/cosmos-sdk/pull/6510/) Field TimeIotaMs now is included in genesis file while exporting.
 * (client) [\#6402](https://github.com/cosmos/cosmos-sdk/issues/6402) Fix `keys add` `--algo` flag which only worked for Tendermint's `secp256k1` default key signing algorithm.

client/tx/tx.go

@@ -188,7 +188,7 @@ func WriteGeneratedTxResponse(
 		return
 	}
 
-	output, err := ctx.JSONMarshaler.MarshalJSON(tx)
+	output, err := ctx.JSONMarshaler.MarshalJSON(tx.GetTx())
 	if rest.CheckInternalServerError(w, err) {
 		return
 	}

types/rest/rest.go

@@ -3,6 +3,7 @@
 package rest
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -442,3 +443,23 @@ func GetRequest(url string) ([]byte, error) {
 
 	return body, nil
 }
+
+// PostRequest defines a wrapper around an HTTP POST request with a provided URL and data.
+// An error is returned if the request or reading the body fails.
+func PostRequest(url string, contentType string, data []byte) ([]byte, error) {
+	res, err := http.Post(url, contentType, bytes.NewBuffer(data)) // nolint:gosec
+	if err != nil {
+		return nil, fmt.Errorf("error while sending post request: %w", err)
+	}
+
+	bz, err := ioutil.ReadAll(res.Body)
+	if err != nil {
+		return nil, fmt.Errorf("error reading response body: %w", err)
+	}
+
+	if err = res.Body.Close(); err != nil {
+		return nil, err
+	}
+
+	return bz, nil
+}

x/bank/client/rest/tx_test.go

@@ -0,0 +1,106 @@
+package rest_test
+
+import (
+	"fmt"
+
+	"github.com/cosmos/cosmos-sdk/simapp"
+	"github.com/cosmos/cosmos-sdk/testutil"
+	"github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/errors"
+	"github.com/cosmos/cosmos-sdk/types/rest"
+	authclient "github.com/cosmos/cosmos-sdk/x/auth/client"
+	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
+	bankrest "github.com/cosmos/cosmos-sdk/x/bank/client/rest"
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
+)
+
+func (s *IntegrationTestSuite) TestCoinSend() {
+	encodingConfig := simapp.MakeEncodingConfig()
+	authclient.Codec = encodingConfig.Marshaler
+
+	val := s.network.Validators[0]
+
+	account, err := getAccountInfo(val)
+	s.Require().NoError(err)
+
+	sendReq := generateSendReq(
+		account,
+		types.Coins{types.NewCoin(s.cfg.BondDenom, types.TokensFromConsensusPower(1))},
+	)
+
+	stdTx, err := submitSendReq(val, sendReq)
+	s.Require().NoError(err)
+
+	s.Require().Nil(stdTx.Signatures)
+	s.Require().Equal([]types.Msg{
+		&banktypes.MsgSend{
+			FromAddress: account.GetAddress(),
+			ToAddress:   account.GetAddress(),
+			Amount:      sendReq.Amount,
+		},
+	}, stdTx.GetMsgs())
+}
+
+func submitSendReq(val *testutil.Validator, req bankrest.SendReq) (authtypes.StdTx, error) {
+	url := fmt.Sprintf("%s/bank/accounts/%s/transfers", val.APIAddress, val.Address)
+
+	bz, err := val.ClientCtx.JSONMarshaler.MarshalJSON(req)
+	if err != nil {
+		return authtypes.StdTx{}, errors.Wrap(err, "error encoding SendReq to json")
+	}
+
+	res, err := rest.PostRequest(url, "application/json", bz)
+	if err != nil {
+		return authtypes.StdTx{}, err
+	}
+
+	var tx authtypes.StdTx
+	err = val.ClientCtx.JSONMarshaler.UnmarshalJSON(res, &tx)
+	if err != nil {
+		return authtypes.StdTx{}, errors.Wrap(err, "error unmarshaling to StdTx SendReq response")
+	}
+
+	return tx, nil
+}
+
+func generateSendReq(from authtypes.AccountI, amount types.Coins) bankrest.SendReq {
+	baseReq := rest.NewBaseReq(
+		from.GetAddress().String(),
+		"someMemo",
+		"some-id",
+		"10000",
+		fmt.Sprintf("%f", 1.0),
+		from.GetAccountNumber(),
+		from.GetSequence(),
+		types.NewCoins(),
+		nil,
+		false,
+	)
+
+	return bankrest.SendReq{
+		BaseReq: baseReq,
+		Amount:  amount,
+	}
+}
+
+func getAccountInfo(val *testutil.Validator) (authtypes.AccountI, error) {
+	url := fmt.Sprintf("%s/auth/accounts/%s", val.APIAddress, val.Address)
+
+	resp, err := rest.GetRequest(url)
+	if err != nil {
+		return nil, err
+	}
+
+	bz, err := rest.ParseResponseWithHeight(val.ClientCtx.JSONMarshaler, resp)
+	if err != nil {
+		return nil, err
+	}
+
+	var acc authtypes.AccountI
+	err = val.ClientCtx.JSONMarshaler.UnmarshalJSON(bz, &acc)
+	if err != nil {
+		return nil, err
+	}
+
+	return acc, nil
+}