controller/vm: add unit tests for VM Controller state machine

internal/controller/vm/export_test.go

@@ -0,0 +1,21 @@
+//go:build windows
+
+package vm
+
+import (
+	"github.com/Microsoft/hcsshim/internal/vm/vmmanager"
+)
+
+// SetManagerForTest configures a Manager with injected dependencies for testing.
+// This is only available in test builds.
+//
+// MUST be called during test setup before any concurrent operations on the Manager.
+//
+// Note: logOutputDone is initialized by NewController() and is NOT reset here.
+// Tests that exercise Wait() in Running/Terminated state must close the channel
+// manually or the Wait call will block on the logOutputDone select.
+func (c *Manager) SetManagerForTest(uvm vmmanager.LifetimeManager, guest GuestManager, state State) {
+	c.uvm = uvm
+	c.guest = guest
+	c.vmState = state
+}

internal/controller/vm/interface.go

@@ -2,6 +2,8 @@
 
 package vm
 
+//go:generate go tool mockgen -source=interface.go -build_constraint=windows -package=mockvmcontroller -destination=../../test/mock/vmcontroller/mock_interface.go
+
 import (
 	"context"
 	"time"
@@ -15,9 +17,18 @@ import (
 	"github.com/Microsoft/go-winio/pkg/guid"
 )
 
+// GuestManager defines the guest operations required by the VM Controller.
+// It combines the core guest manager, security policy, and HvSocket interfaces
+// from the guestmanager package into a single interface for dependency injection.
+type GuestManager interface {
+	guestmanager.Manager
+	guestmanager.SecurityPolicyManager
+	guestmanager.HVSocketManager
+}
+
 type Controller interface {
 	// Guest returns the guest manager instance for this VM.
-	Guest() *guestmanager.Guest
+	Guest() GuestManager
 
 	// State returns the current VM state.
 	State() State

internal/controller/vm/state_test.go

@@ -0,0 +1,33 @@
+//go:build windows
+
+package vm_test
+
+import (
+	"testing"
+
+	vm "github.com/Microsoft/hcsshim/internal/controller/vm"
+)
+
+func TestStateString(t *testing.T) {
+	tests := []struct {
+		state vm.State
+		want  string
+	}{
+		{vm.StateNotCreated, "NotCreated"},
+		{vm.StateCreated, "Created"},
+		{vm.StateRunning, "Running"},
+		{vm.StateTerminated, "Terminated"},
+		{vm.StateInvalid, "Invalid"},
+		{vm.State(99), "Unknown"},
+		{vm.State(-1), "Unknown"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.want, func(t *testing.T) {
+			t.Parallel()
+			if got := tt.state.String(); got != tt.want {
+				t.Errorf("State(%d).String() = %q, want %q", tt.state, got, tt.want)
+			}
+		})
+	}
+}

internal/controller/vm/vm.go

@@ -33,8 +33,8 @@ import (
 // and its associated resources.
 type Manager struct {
 	vmID  string
-	uvm   *vmmanager.UtilityVM
-	guest *guestmanager.Guest
+	uvm   vmmanager.LifetimeManager
+	guest GuestManager
 
 	// vmState tracks the current state of the VM lifecycle.
 	// Access must be guarded by mu.
@@ -70,7 +70,7 @@ func NewController() *Manager {
 
 // Guest returns the guest manager instance for this VM.
 // The guest manager provides access to guest-host communication.
-func (c *Manager) Guest() *guestmanager.Guest {
+func (c *Manager) Guest() GuestManager {
 	return c.guest
 }