feat(gov): support v1.Proposal in v1beta1.Proposal.Content (backport #…

…14347) (#14398)

Co-authored-by: Robert Zaremba <robert@zaremba.ch>

CHANGELOG.md

@@ -49,6 +49,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (types) [#14332](https://github.com/cosmos/cosmos-sdk/issues/14332) Reduce state export time by 50%.
 * (types) [#14163](https://github.com/cosmos/cosmos-sdk/pull/14163) Refactor `(coins Coins) Validate()` to avoid unnecessary map.
 * [#13881](https://github.com/cosmos/cosmos-sdk/pull/13881) Optimize iteration on nested cached KV stores and other operations in general.
+* (x/gov) [#14347](https://github.com/cosmos/cosmos-sdk/pull/14347) Support `v1.Proposal` message in `v1beta1.Proposal.Content`.
 
 ### API Breaking Changes
 

x/gov/migrations/v3/convert.go

@@ -5,6 +5,7 @@ import (
 
 	codectypes "github.com/cosmos/cosmos-sdk/codec/types"
 	"github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	authtypes "github.com/cosmos/cosmos-sdk/x/auth/types"
 	v1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1"
 	"github.com/cosmos/cosmos-sdk/x/gov/types/v1beta1"
@@ -13,6 +14,7 @@ import (
 // ConvertToLegacyProposal takes a new proposal and attempts to convert it to the
 // legacy proposal format. This conversion is best effort. New proposal types that
 // don't have a legacy message will return a "nil" content.
+// Returns error when the amount of messages in `proposal` is different than one.
 func ConvertToLegacyProposal(proposal v1.Proposal) (v1beta1.Proposal, error) {
 	var err error
 	legacyProposal := v1beta1.Proposal{
@@ -46,17 +48,25 @@ func ConvertToLegacyProposal(proposal v1.Proposal) (v1beta1.Proposal, error) {
 	if err != nil {
 		return v1beta1.Proposal{}, err
 	}
-	for _, msg := range msgs {
-		if legacyMsg, ok := msg.(*v1.MsgExecLegacyContent); ok {
-			// check that the content struct can be unmarshalled
-			_, err := v1.LegacyContentFromMessage(legacyMsg)
-			if err != nil {
-				return v1beta1.Proposal{}, err
-			}
-			legacyProposal.Content = legacyMsg.Content
+	if len(msgs) != 1 {
+		return v1beta1.Proposal{}, sdkerrors.ErrInvalidType.Wrap("can't convert a gov/v1 Proposal to gov/v1beta1 Proposal when amount of proposal messages is more than one")
+	}
+	if legacyMsg, ok := msgs[0].(*v1.MsgExecLegacyContent); ok {
+		// check that the content struct can be unmarshalled
+		_, err := v1.LegacyContentFromMessage(legacyMsg)
+		if err != nil {
+			return v1beta1.Proposal{}, err
 		}
+		legacyProposal.Content = legacyMsg.Content
+		return legacyProposal, nil
 	}
-	return legacyProposal, nil
+	// hack to fill up the content with the first message
+	// this is to support clients that have not yet (properly) use gov/v1 endpoints
+	// https://github.com/cosmos/cosmos-sdk/issues/14334
+	// VerifyBasic assures that we have at least one message.
+	legacyProposal.Content, err = codectypes.NewAnyWithValue(msgs[0])
+
+	return legacyProposal, err
 }
 
 func ConvertToLegacyTallyResult(tally *v1.TallyResult) (v1beta1.TallyResult, error) {

x/gov/migrations/v3/convert_test.go

@@ -6,10 +6,12 @@ import (
 
 	"cosmossdk.io/math"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 	"github.com/cosmos/cosmos-sdk/types/tx"
 	v3 "github.com/cosmos/cosmos-sdk/x/gov/migrations/v3"
 	v1 "github.com/cosmos/cosmos-sdk/x/gov/types/v1"
 	"github.com/cosmos/cosmos-sdk/x/gov/types/v1beta1"
+	upgradetypes "github.com/cosmos/cosmos-sdk/x/upgrade/types"
 	"github.com/stretchr/testify/require"
 )
 
@@ -61,11 +63,46 @@ func TestConvertToLegacyProposal(t *testing.T) {
 				require.Equal(t, v1beta1Proposal.FinalTallyResult.No, sdk.NewInt(0))
 				require.Equal(t, v1beta1Proposal.FinalTallyResult.NoWithVeto, sdk.NewInt(0))
 				require.Equal(t, v1beta1Proposal.FinalTallyResult.Abstain, sdk.NewInt(0))
+				tp, ok := v1beta1Proposal.Content.GetCachedValue().(*v1beta1.TextProposal)
+				require.Truef(t, ok, "expected *TextProposal, got %T", v1beta1Proposal.Content.GetCachedValue())
+				require.Equal(t, tp.Title, "title")
+				require.Equal(t, tp.Description, "description")
 			}
 		})
 	}
 }
 
+func TestConvertToLegacyProposalContent(t *testing.T) {
+	msg := upgradetypes.MsgSoftwareUpgrade{Authority: "gov module", Plan: upgradetypes.Plan{Name: "test upgrade"}}
+	msgsAny, err := tx.SetMsgs([]sdk.Msg{&msg})
+	require.NoError(t, err)
+	tallyResult := v1.EmptyTallyResult()
+	proposal := v1.Proposal{
+		Id:               1,
+		Status:           v1.StatusDepositPeriod,
+		Messages:         msgsAny,
+		Metadata:         "proposal metadata",
+		FinalTallyResult: &tallyResult,
+	}
+
+	legacyP, err := v3.ConvertToLegacyProposal(proposal)
+	require.NoError(t, err)
+	tp, ok := legacyP.Content.GetCachedValue().(*upgradetypes.MsgSoftwareUpgrade)
+	require.Truef(t, ok, "expected *MsgSoftwareUpgrade, got %T", legacyP.Content.GetCachedValue())
+	require.Equal(t, &msg, tp)
+
+	// more than one message is not supported
+	proposal.Messages, err = tx.SetMsgs([]sdk.Msg{&msg, &msg})
+	require.NoError(t, err)
+	_, err = v3.ConvertToLegacyProposal(proposal)
+	require.ErrorIs(t, sdkerrors.ErrInvalidType, err)
+
+	// zero messages is not supported
+	proposal.Messages = nil
+	_, err = v3.ConvertToLegacyProposal(proposal)
+	require.ErrorIs(t, sdkerrors.ErrInvalidType, err)
+}
+
 func TestConvertToLegacyTallyResult(t *testing.T) {
 	tallyResult := v1.EmptyTallyResult()
 	testCases := map[string]struct {