Proper systemerror follow-up (#715)

* Add custom NoSuchContract error

* Return custom NoSuchContract error from WasmQuerier

* Add custom NoSuchContract error

* Use custom ErrNoSuchContract error

Map to corresponding wasmvmtypes error

* Handle wrapped errors

Co-authored-by: Alex Peters <alpe@users.noreply.github.com>

x/wasm/keeper/query_plugins.go

@@ -2,6 +2,7 @@ package keeper
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 
 	"github.com/cosmos/cosmos-sdk/baseapp"
@@ -52,7 +53,14 @@ func (q QueryHandler) Query(request wasmvmtypes.QueryRequest, gasLimit uint64) (
 	defer func() {
 		q.Ctx.GasMeter().ConsumeGas(subCtx.GasMeter().GasConsumed(), "contract sub-query")
 	}()
-	return q.Plugins.HandleQuery(subCtx, q.Caller, request)
+
+	res, err := q.Plugins.HandleQuery(subCtx, q.Caller, request)
+	// Error mapping
+	var noSuchContract *types.ErrNoSuchContract
+	if ok := errors.As(err, &noSuchContract); ok {
+		return res, wasmvmtypes.NoSuchContract{Addr: noSuchContract.Addr}
+	}
+	return res, err
 }
 
 func (q QueryHandler) GasConsumed() uint64 {
@@ -483,7 +491,7 @@ func WasmQuerier(k wasmQueryKeeper) func(ctx sdk.Context, request *wasmvmtypes.W
 			}
 			info := k.GetContractInfo(ctx, addr)
 			if info == nil {
-				return nil, wasmvmtypes.NoSuchContract{Addr: request.ContractInfo.ContractAddr}
+				return nil, &types.ErrNoSuchContract{Addr: request.ContractInfo.ContractAddr}
 			}
 
 			res := wasmvmtypes.ContractInfoResponse{

x/wasm/keeper/query_plugins_test.go

@@ -4,6 +4,9 @@ import (
 	"encoding/json"
 	"testing"
 
+	"github.com/cosmos/cosmos-sdk/store"
+	dbm "github.com/tendermint/tm-db"
+
 	wasmvmtypes "github.com/CosmWasm/wasmvm/types"
 	sdk "github.com/cosmos/cosmos-sdk/types"
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
@@ -442,6 +445,34 @@ func TestContractInfoWasmQuerier(t *testing.T) {
 	}
 }
 
+func TestQueryErrors(t *testing.T) {
+	specs := map[string]struct {
+		src    error
+		expErr error
+	}{
+		"no error": {},
+		"no such contract": {
+			src:    &types.ErrNoSuchContract{Addr: "contract-addr"},
+			expErr: wasmvmtypes.NoSuchContract{Addr: "contract-addr"},
+		},
+		"no such contract - wrapped": {
+			src:    sdkerrors.Wrap(&types.ErrNoSuchContract{Addr: "contract-addr"}, "my additional data"),
+			expErr: wasmvmtypes.NoSuchContract{Addr: "contract-addr"},
+		},
+	}
+	for name, spec := range specs {
+		t.Run(name, func(t *testing.T) {
+			mock := WasmVMQueryHandlerFn(func(ctx sdk.Context, caller sdk.AccAddress, request wasmvmtypes.QueryRequest) ([]byte, error) {
+				return nil, spec.src
+			})
+			ctx := sdk.Context{}.WithGasMeter(sdk.NewInfiniteGasMeter()).WithMultiStore(store.NewCommitMultiStore(dbm.NewMemDB()))
+			q := NewQueryHandler(ctx, mock, sdk.AccAddress{}, NewDefaultWasmGasRegister())
+			_, gotErr := q.Query(wasmvmtypes.QueryRequest{}, 1)
+			assert.Equal(t, spec.expErr, gotErr)
+		})
+	}
+}
+
 type mockWasmQueryKeeper struct {
 	GetContractInfoFn func(ctx sdk.Context, contractAddress sdk.AccAddress) *types.ContractInfo
 	QueryRawFn        func(ctx sdk.Context, contractAddress sdk.AccAddress, key []byte) []byte

x/wasm/types/errors.go

@@ -69,4 +69,23 @@ var (
 
 	// ErrInvalidEvent error if an attribute/event from the contract is invalid
 	ErrInvalidEvent = sdkErrors.Register(DefaultCodespace, 21, "invalid event")
+
+	//  error if an address does not belong to a contract (just for registration)
+	_ = sdkErrors.Register(DefaultCodespace, 22, "no such contract")
 )
+
+type ErrNoSuchContract struct {
+	Addr string
+}
+
+func (m *ErrNoSuchContract) Error() string {
+	return "no such contract: " + m.Addr
+}
+
+func (m *ErrNoSuchContract) ABCICode() uint32 {
+	return 22
+}
+
+func (m *ErrNoSuchContract) Codespace() string {
+	return DefaultCodespace
+}