add generic call/transact

accounts/abi/bind/v2/lib.go

@@ -345,19 +345,23 @@ func (it *EventIterator[T]) Close() error {
 
 // Transact creates and submits a transaction to the bound contract instance
 // using the provided abi-encoded input (or nil).
-func Transact(instance *ContractInstance, opts *bind.TransactOpts, packedInput []byte) (*types.Transaction, error) {
+func Transact(instance *ContractInstance, opts *bind.TransactOpts, input []byte) (*types.Transaction, error) {
 	var (
 		addr    = instance.Address
 		backend = instance.Backend
 	)
 	c := bind.NewBoundContract(addr, abi.ABI{}, backend, backend, backend)
-	return c.RawTransact(opts, packedInput)
+	return c.RawTransact(opts, input)
 }
 
 // Call performs an eth_call on the given bound contract instance, using the
 // provided abi-encoded input (or nil).
-func Call(instance *ContractInstance, opts *bind.CallOpts, packedInput []byte) ([]byte, error) {
+func Call[T any](instance *ContractInstance, opts *bind.CallOpts, packedInput []byte, unpack func([]byte) (*T, error)) (*T, error) {
 	backend := instance.Backend
 	c := bind.NewBoundContract(instance.Address, abi.ABI{}, backend, backend, backend)
-	return c.CallRaw(opts, packedInput)
+	packedOutput, err := c.CallRaw(opts, packedInput)
+	if err != nil {
+		return nil, err
+	}
+	return unpack(packedOutput)
 }

accounts/abi/bind/v2/lib_test.go

@@ -148,21 +148,17 @@ func TestDeploymentLibraries(t *testing.T) {
 		t.Fatalf("pack function input err: %v\n", doInput)
 	}
 
-	cABI, err := nested_libraries.C1MetaData.GetAbi()
-	if err != nil {
-		t.Fatalf("error getting abi object: %v", err)
-	}
 	contractAddr := res.Addrs[nested_libraries.C1MetaData.Pattern]
-	boundC := bind.NewBoundContract(contractAddr, *cABI, bindBackend, bindBackend, bindBackend)
 	callOpts := &bind.CallOpts{
 		From:    common.Address{},
 		Context: context.Background(),
 	}
-	callRes, err := boundC.CallRaw(callOpts, doInput)
-	if err != nil {
-		t.Fatalf("err calling contract: %v", err)
+
+	ctrctInstance := &ContractInstance{
+		Address: contractAddr,
+		Backend: bindBackend,
 	}
-	internalCallCount, err := c.UnpackDo(callRes)
+	internalCallCount, err := Call[big.Int](ctrctInstance, callOpts, doInput, ctrct.UnpackDo)
 	if err != nil {
 		t.Fatalf("err unpacking result: %v", err)
 	}