Refactor: Move callGasLimit check to own file with test (#70)

Author: hazim-j

pkg/modules/checks/callgas.go

@@ -0,0 +1,18 @@
+package checks
+
+import (
+	"fmt"
+
+	"github.com/stackup-wallet/stackup-bundler/pkg/gas"
+	"github.com/stackup-wallet/stackup-bundler/pkg/userop"
+)
+
+// ValidateCallGasLimit checks the callGasLimit is at least the cost of a CALL with non-zero value.
+func ValidateCallGasLimit(op *userop.UserOperation) error {
+	cg := gas.NewDefaultOverhead().NonZeroValueCall()
+	if op.CallGasLimit.Cmp(cg) < 0 {
+		return fmt.Errorf("callGasLimit: below expected gas of %s", cg.String())
+	}
+
+	return nil
+}

pkg/modules/checks/callgas_test.go

@@ -0,0 +1,46 @@
+package checks
+
+import (
+	"math/big"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/stackup-wallet/stackup-bundler/internal/testutils"
+	"github.com/stackup-wallet/stackup-bundler/pkg/gas"
+)
+
+// TestOpCGLessThanOH calls checks.ValidateCallGasLimit where callGas < overhead. Expect error.
+func TestOpCGLessThanOH(t *testing.T) {
+	op := testutils.MockValidInitUserOp()
+	cg := gas.NewDefaultOverhead().NonZeroValueCall()
+	op.CallGasLimit = big.NewInt(0).Sub(cg, common.Big1)
+	err := ValidateCallGasLimit(op)
+
+	if err == nil {
+		t.Fatalf("got nil, want err")
+	}
+}
+
+// TestOpCGEqualOH calls checks.ValidateCallGasLimit where callGas == overhead. Expect nil.
+func TestOpCGEqualOH(t *testing.T) {
+	op := testutils.MockValidInitUserOp()
+	cg := gas.NewDefaultOverhead().NonZeroValueCall()
+	op.CallGasLimit = big.NewInt(0).Add(cg, common.Big0)
+	err := ValidateCallGasLimit(op)
+
+	if err != nil {
+		t.Fatalf("got %v, want nil", err)
+	}
+}
+
+// TestOpCGMoreThanOH calls checks.ValidateCallGasLimit where callGas > overhead. Expect nil.
+func TestOpCGMoreThanOH(t *testing.T) {
+	op := testutils.MockValidInitUserOp()
+	cg := gas.NewDefaultOverhead().NonZeroValueCall()
+	op.CallGasLimit = big.NewInt(0).Add(cg, common.Big1)
+	err := ValidateCallGasLimit(op)
+
+	if err != nil {
+		t.Fatalf("got %v, want nil", err)
+	}
+}

pkg/modules/checks/sanitychecks.go

@@ -5,20 +5,9 @@ import (
 	"fmt"
 
 	"github.com/ethereum/go-ethereum/ethclient"
-	"github.com/stackup-wallet/stackup-bundler/pkg/gas"
 	"github.com/stackup-wallet/stackup-bundler/pkg/userop"
 )
 
-// Checks the callGasLimit is at least the cost of a CALL with non-zero value.
-func checkCallGasLimit(op *userop.UserOperation) error {
-	cg := gas.NewDefaultOverhead().NonZeroValueCall()
-	if op.CallGasLimit.Cmp(cg) < 0 {
-		return fmt.Errorf("callGasLimit: below expected gas of %s", cg.String())
-	}
-
-	return nil
-}
-
 // The maxFeePerGas and maxPriorityFeePerGas are above a configurable minimum value that the client
 // is willing to accept. At the minimum, they are sufficiently high to be included with the current
 // block.basefee.

pkg/modules/checks/standalone.go

@@ -45,7 +45,7 @@ func (s *Standalone) ValidateOpValues() modules.UserOpHandlerFunc {
 		g.Go(func() error { return ValidateInitCode(ctx.UserOp, gs) })
 		g.Go(func() error { return ValidateVerificationGas(ctx.UserOp, s.maxVerificationGas) })
 		g.Go(func() error { return ValidatePaymasterAndData(ctx.UserOp, gc, gs) })
-		g.Go(func() error { return checkCallGasLimit(ctx.UserOp) })
+		g.Go(func() error { return ValidateCallGasLimit(ctx.UserOp) })
 		g.Go(func() error { return checkFeePerGas(s.eth, ctx.UserOp) })
 
 		return g.Wait()