Add tests for types of meta fault (#3824)

This adds compound tests for whether a fault is a transient error, or
whether it's an error due to an attempt to power off an already powered
off VM.

The former is widely reimplemented by clients, and often missing some
types. The latter is extremely useful to have when mapping desired
state to imperative.

Signed-off-by: George Hicken <[email protected]>

Author: hickeng

fault/meta_types.go

@@ -0,0 +1,41 @@
+// © Broadcom. All Rights Reserved.
+// The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
+// SPDX-License-Identifier: Apache-2.0
+
+package fault
+
+import "github.com/vmware/govmomi/vim25/types"
+
+// IsAlreadyPoweredOffError verifies that the error is an InvalidPowerState
+// error and returns true if the existing state from the error is powered off
+func IsAlreadyPoweredOffError(err any) bool {
+	var existingState types.VirtualMachinePowerState
+
+	In(err, func(
+		fault types.BaseMethodFault,
+		localizedMessage string,
+		localizableMessages []types.LocalizableMessage) bool {
+		if invalidPowerState, ok := fault.(*types.InvalidPowerState); ok {
+			existingState = invalidPowerState.ExistingState
+
+			return true
+		}
+
+		return false
+	})
+
+	return existingState == types.VirtualMachinePowerStatePoweredOff
+}
+
+// IsTransientError checks whether the error type indicates an error that is
+// likely to resolve without explicit action in calling logic.
+// Some of those are highly transient, such as TaskInProgress. Others are
+// potentially longer term, such as HostCommunication; they are inherently
+// transient but may not resolve in a short time frame.
+func IsTransientError(err any) bool {
+	return Is(err, &types.TaskInProgress{}) ||
+		Is(err, &types.NetworkDisruptedAndConfigRolledBack{}) ||
+		Is(err, &types.VAppTaskInProgress{}) ||
+		Is(err, &types.FailToLockFaultToleranceVMs{}) ||
+		Is(err, &types.HostCommunication{})
+}

fault/meta_types_test.go

@@ -0,0 +1,45 @@
+// © Broadcom. All Rights Reserved.
+// The term "Broadcom" refers to Broadcom Inc. and/or its subsidiaries.
+// SPDX-License-Identifier: Apache-2.0
+
+package fault_test
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+
+	"github.com/vmware/govmomi/fault"
+	"github.com/vmware/govmomi/task"
+	"github.com/vmware/govmomi/vim25/types"
+)
+
+func TestAlreadyPoweredOff(t *testing.T) {
+	var (
+		errFalse any
+		errTrue  any
+	)
+
+	errFalse = task.Error{
+		LocalizedMethodFault: &types.LocalizedMethodFault{
+			Fault: &types.InvalidPowerState{
+				ExistingState:  types.VirtualMachinePowerStateSuspended,
+				RequestedState: types.VirtualMachinePowerStatePoweredOff,
+			},
+			LocalizedMessage: "vm must be powered on to power off",
+		},
+	}
+
+	errTrue = task.Error{
+		LocalizedMethodFault: &types.LocalizedMethodFault{
+			Fault: &types.InvalidPowerState{
+				ExistingState:  types.VirtualMachinePowerStatePoweredOff,
+				RequestedState: types.VirtualMachinePowerStatePoweredOff,
+			},
+			LocalizedMessage: "vm must be powered on to power off",
+		},
+	}
+
+	assert.False(t, fault.IsAlreadyPoweredOffError(errFalse))
+	assert.True(t, fault.IsAlreadyPoweredOffError(errTrue))
+}