feat: binding error to match expected

x/alliance/bindings/query_plugin.go

@@ -2,6 +2,7 @@ package bindings
 
 import (
 	"encoding/json"
+	"fmt"
 
 	sdk "github.com/cosmos/cosmos-sdk/types"
 
@@ -48,7 +49,7 @@ func CustomQuerier(q *QueryPlugin) func(ctx sdk.Context, request json.RawMessage
 				validator,
 			)
 		}
-		return nil, nil
+		return nil, fmt.Errorf("unknown query")
 	}
 }
 

x/alliance/bindings/tests/query_plugin_test.go

@@ -203,3 +203,21 @@ func TestDelegationRewardsQuery(t *testing.T) {
 		},
 	}, response)
 }
+
+func TestCustomQuerier(t *testing.T) {
+	app, ctx := createTestContext(t)
+	genesisTime := ctx.BlockTime()
+	app.AllianceKeeper.InitGenesis(ctx, &types.GenesisState{
+		Params: types.DefaultParams(),
+		Assets: []types.AllianceAsset{
+			types.NewAllianceAsset(AllianceDenom, sdk.NewDec(2), sdk.ZeroDec(), sdk.NewDec(5), sdk.NewDec(0), genesisTime),
+		},
+	})
+
+	querierPlugin := bindings.NewAllianceQueryPlugin(app.AllianceKeeper)
+	querier := bindings.CustomQuerier(querierPlugin)
+
+	queryBytes := []byte("{\"random\": \"query\"}")
+	_, err := querier(ctx, queryBytes)
+	require.Error(t, err)
+}