feat: delete subspace (#396)

x/params/keeper/keeper.go

@@ -1,6 +1,8 @@
 package keeper
 
 import (
+	"fmt"
+
 	"github.com/cosmos/cosmos-sdk/codec"
 	storetypes "github.com/cosmos/cosmos-sdk/store/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
@@ -71,3 +73,12 @@ func (k Keeper) GetSubspaces() []types.Subspace {
 
 	return spaces
 }
+
+func (k Keeper) DeleteSubspace(s string) error {
+	_, ok := k.spaces[s]
+	if !ok {
+		return fmt.Errorf("can not delete subspace %s because it does not exist", s)
+	}
+	delete(k.spaces, s)
+	return nil
+}

x/params/keeper/keeper_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"cosmossdk.io/math"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"github.com/stretchr/testify/suite"
 	tmproto "github.com/tendermint/tendermint/proto/tendermint/types"
@@ -278,3 +279,21 @@ func TestJSONUpdate(t *testing.T) {
 	space.Get(ctx, key, &param)
 	require.Equal(t, paramJSON{40964096, "goodbyeworld"}, param)
 }
+
+func TestDeleteSubspace(t *testing.T) {
+	_, _, _, _, keeper := testComponents()
+	name := "test"
+
+	t.Run("should return an error if DeleteSubspace is invoked on a non-existent subspace", func(t *testing.T) {
+		err := keeper.DeleteSubspace(name)
+		assert.Error(t, err)
+	})
+	t.Run("should return no error if DeleteSubspace is invoked on a subspace", func(t *testing.T) {
+		keeper.Subspace(name)
+		err := keeper.DeleteSubspace(name)
+		assert.NoError(t, err)
+		_, exists := keeper.GetSubspace(name)
+		assert.False(t, exists)
+	})
+
+}