mi: fix native return-value handling (#2537)

Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
Signed-off-by: Jan-Otto Kröpke <mail@jkroepke.de>

internal/headers/hcs/hcs_test.go

@@ -18,16 +18,38 @@
 package hcs_test
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/prometheus-community/windows_exporter/internal/headers/hcs"
 	"github.com/stretchr/testify/require"
 )
 
+// skipWithoutHCS skips the test if the Host Compute Service is not available,
+// e.g. on hosts without the Containers feature.
+func skipWithoutHCS(t *testing.T, err error) {
+	t.Helper()
+
+	if errors.Is(err, hcs.ErrServiceNotAvailable) {
+		t.Skip("Host Compute Service is not available")
+	}
+}
+
+func TestCreateOperation(t *testing.T) {
+	t.Parallel()
+
+	operation, err := hcs.CreateOperation()
+	require.NoError(t, err)
+	require.NotZero(t, operation)
+
+	hcs.CloseOperation(operation)
+}
+
 func TestGetContainers(t *testing.T) {
 	t.Parallel()
 
 	containers, err := hcs.GetContainers()
+	skipWithoutHCS(t, err)
 	require.NoError(t, err)
 	require.NotNil(t, containers)
 }
@@ -36,6 +58,7 @@ func TestOpenContainer(t *testing.T) {
 	t.Parallel()
 
 	containers, err := hcs.GetContainers()
+	skipWithoutHCS(t, err)
 	require.NoError(t, err)
 
 	if len(containers) == 0 {
@@ -51,5 +74,6 @@ func TestOpenContainerNotFound(t *testing.T) {
 	t.Parallel()
 
 	_, err := hcs.GetContainerStatistics("f3056b79b36ddfe203376473e2aeb4922a8ca7c5d8100764e5829eb5552fe09b")
+	skipWithoutHCS(t, err)
 	require.ErrorIs(t, err, hcs.ErrIDNotFound)
 }

internal/headers/hcs/syscall.go

@@ -18,6 +18,7 @@
 package hcs
 
 import (
+	"errors"
 	"fmt"
 	"unsafe"
 
@@ -38,10 +39,18 @@ var (
 )
 
 // CreateOperation creates a new operation.
+//
+// HcsCreateOperation returns the operation handle, or NULL on failure.
+//
+// https://learn.microsoft.com/en-us/virtualization/api/hcs/reference/hcscreateoperation
 func CreateOperation() (Operation, error) {
-	r1, r2, _ := procHcsCreateOperation.Call(0, 0)
-	if r2 != 0 {
-		return 0, fmt.Errorf("HcsCreateOperation failed: HRESULT 0x%X: %w", r2, Win32FromHResult(r2))
+	r1, _, err := procHcsCreateOperation.Call(0, 0)
+	if r1 == 0 {
+		if errors.Is(err, windows.ERROR_SUCCESS) {
+			err = ErrInvalidHandle
+		}
+
+		return 0, fmt.Errorf("HcsCreateOperation failed: %w", err)
 	}
 
 	return Operation(r1), nil
@@ -102,13 +111,13 @@ func OpenComputeSystem(id string) (ComputeSystem, error) {
 }
 
 func GetComputeSystemProperties(system ComputeSystem, operation Operation, propertyQuery *uint16) error {
-	r1, _, err := procHcsGetComputeSystemProperties.Call(
+	r1, _, _ := procHcsGetComputeSystemProperties.Call(
 		uintptr(system),
 		uintptr(operation),
 		uintptr(unsafe.Pointer(propertyQuery)),
 	)
 	if r1 != 0 {
-		return fmt.Errorf("HcsGetComputeSystemProperties failed: HRESULT 0x%X: %w", r1, err)
+		return fmt.Errorf("HcsGetComputeSystemProperties failed: HRESULT 0x%X: %w", r1, Win32FromHResult(r1))
 	}
 
 	return nil

internal/headers/hcs/types.go

@@ -26,7 +26,11 @@ import (
 
 var (
 	ErrEmptyResultDocument = errors.New("empty result document")
+	ErrInvalidHandle       = errors.New("invalid handle")
 	ErrIDNotFound          = windows.Errno(2151088398)
+	// ErrServiceNotAvailable is HCS_E_SERVICE_NOT_AVAILABLE, returned when the
+	// Host Compute Service is not installed, e.g. without the Containers feature.
+	ErrServiceNotAvailable = windows.Errno(2151088411)
 )
 
 type (