Handle both stargate and any CosmosMsg variant

types/msg.go

@@ -103,10 +103,47 @@ type CosmosMsg struct {
 	Gov          *GovMsg          `json:"gov,omitempty"`
 	IBC          *IBCMsg          `json:"ibc,omitempty"`
 	Staking      *StakingMsg      `json:"staking,omitempty"`
-	Stargate     *StargateMsg     `json:"stargate,omitempty"`
+	Any          *AnyMsg          `json:"any,omitempty"`
 	Wasm         *WasmMsg         `json:"wasm,omitempty"`
 }
 
+func (m *CosmosMsg) UnmarshalJSON(data []byte) error {
+	// We need a custom unmarshaler to parse both the "stargate" and "any" variants
+	type InternalCosmosMsg struct {
+		Bank         *BankMsg         `json:"bank,omitempty"`
+		Custom       json.RawMessage  `json:"custom,omitempty"`
+		Distribution *DistributionMsg `json:"distribution,omitempty"`
+		Gov          *GovMsg          `json:"gov,omitempty"`
+		IBC          *IBCMsg          `json:"ibc,omitempty"`
+		Staking      *StakingMsg      `json:"staking,omitempty"`
+		Any          *AnyMsg          `json:"any,omitempty"`
+		Wasm         *WasmMsg         `json:"wasm,omitempty"`
+		Stargate     *AnyMsg          `json:"stargate,omitempty"`
+	}
+	var tmp InternalCosmosMsg
+	err := json.Unmarshal(data, &tmp)
+	if err != nil {
+		return err
+	}
+
+	// Use "Any" for both variants
+	if tmp.Any == nil && tmp.Stargate != nil {
+		tmp.Any = tmp.Stargate
+	}
+
+	*m = CosmosMsg{
+		Bank:         tmp.Bank,
+		Custom:       tmp.Custom,
+		Distribution: tmp.Distribution,
+		Gov:          tmp.Gov,
+		IBC:          tmp.IBC,
+		Staking:      tmp.Staking,
+		Any:          tmp.Any,
+		Wasm:         tmp.Wasm,
+	}
+	return nil
+}
+
 type BankMsg struct {
 	Send *SendMsg `json:"send,omitempty"`
 	Burn *BurnMsg `json:"burn,omitempty"`
@@ -272,9 +309,9 @@ type FundCommunityPoolMsg struct {
 	Amount Coins `json:"amount"`
 }
 
-// StargateMsg is encoded the same way as a protobof [Any](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/any.proto).
+// AnyMsg is encoded the same way as a protobof [Any](https://github.com/protocolbuffers/protobuf/blob/master/src/google/protobuf/any.proto).
 // This is the same structure as messages in `TxBody` from [ADR-020](https://github.com/cosmos/cosmos-sdk/blob/master/docs/architecture/adr-020-protobuf-transaction-encoding.md)
-type StargateMsg struct {
+type AnyMsg struct {
 	TypeURL string `json:"type_url"`
 	Value   []byte `json:"value"`
 }

types/msg_test.go

@@ -1,6 +1,7 @@
 package types
 
 import (
+	"encoding/base64"
 	"encoding/json"
 	"testing"
 
@@ -76,6 +77,35 @@ func TestWasmMsgInstantiate2Serialization(t *testing.T) {
 	require.Equal(t, []byte{0x52, 0x43, 0x95, 0x6b, 0x38, 0x62, 0xc2, 0x8a}, msg.Instantiate2.Salt)
 }
 
+func TestAnyMsgSerialization(t *testing.T) {
+	expectedData, err := base64.StdEncoding.DecodeString("5yu/rQ+HrMcxH1zdga7P5hpGMLE=")
+	require.NoError(t, err)
+
+	// test backwards compatibility with old stargate variant
+	document1 := []byte(`{"stargate":{"type_url":"/cosmos.foo.v1beta.MsgBar","value":"5yu/rQ+HrMcxH1zdga7P5hpGMLE="}}`)
+	var res CosmosMsg
+	err = json.Unmarshal(document1, &res)
+	require.NoError(t, err)
+	require.Equal(t, CosmosMsg{
+		Any: &AnyMsg{
+			TypeURL: "/cosmos.foo.v1beta.MsgBar",
+			Value:   expectedData,
+		},
+	}, res)
+
+	// test new any variant
+	document2 := []byte(`{"any":{"type_url":"/cosmos.foo.v1beta.MsgBar","value":"5yu/rQ+HrMcxH1zdga7P5hpGMLE="}}`)
+	var res2 CosmosMsg
+	err = json.Unmarshal(document2, &res2)
+	require.NoError(t, err)
+	require.Equal(t, res, res2)
+
+	// serializing should use the new any variant
+	serialized, err := json.Marshal(res)
+	require.NoError(t, err)
+	require.Equal(t, document2, serialized)
+}
+
 func TestGovMsgVoteSerialization(t *testing.T) {
 	document := []byte(`{"vote":{"proposal_id":4,"vote":"no_with_veto"}}`)