fix(hub): remove stale smart_devices records when a drive is no longer reported (#2178)

* Fix duplicate /dev/sdg-style entries

* only prune devices after complete refreshes

---------

Co-authored-by: henrygd <hank@henrygd.me>

internal/hub/systems/system_smart_test.go

@@ -7,10 +7,53 @@ import (
 	"testing"
 	"time"
 
+	"github.com/henrygd/beszel/internal/entities/smart"
+	esystem "github.com/henrygd/beszel/internal/entities/system"
 	"github.com/henrygd/beszel/internal/hub/expirymap"
+	_ "github.com/henrygd/beszel/internal/migrations"
+
+	"github.com/pocketbase/pocketbase/core"
+	pbtests "github.com/pocketbase/pocketbase/tests"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"golang.org/x/crypto/ssh"
 )
 
+// stubHub implements hubLike using a plain pocketbase test app, so
+// smart-device DB tests can run in-package without an import cycle to
+// internal/hub (which imports this package).
+type stubHub struct{ core.App }
+
+func (stubHub) GetSSHKey(dataDir string) (ssh.Signer, error) { return nil, nil }
+func (stubHub) HandleSystemAlerts(systemRecord *core.Record, data *esystem.CombinedData) error {
+	return nil
+}
+func (stubHub) HandleStatusAlerts(status string, systemRecord *core.Record) error { return nil }
+func (stubHub) CancelPendingStatusAlerts(systemID string)                         {}
+
+// newTestSystemWithHub creates a System backed by a real (temp) database, along
+// with a matching "systems" record, for tests that need to exercise DB reads/writes.
+func newTestSystemWithHub(t *testing.T) (*System, *pbtests.TestApp) {
+	t.Helper()
+	testApp, err := pbtests.NewTestApp(t.TempDir())
+	require.NoError(t, err)
+	t.Cleanup(testApp.Cleanup)
+
+	sm := &SystemManager{hub: stubHub{testApp}, smartFetchMap: expirymap.New[smartFetchState](time.Hour)}
+	t.Cleanup(sm.smartFetchMap.StopCleaner)
+
+	col, err := testApp.FindCachedCollectionByNameOrId("systems")
+	require.NoError(t, err)
+	systemRecord := core.NewRecord(col)
+	systemRecord.Set("name", "test-system")
+	systemRecord.Set("host", "127.0.0.1")
+	systemRecord.Set("port", "45876")
+	require.NoError(t, testApp.SaveNoValidate(systemRecord))
+
+	sys := &System{Id: systemRecord.Id, manager: sm}
+	return sys, testApp
+}
+
 func TestRecordSmartFetchResult(t *testing.T) {
 	sm := &SystemManager{smartFetchMap: expirymap.New[smartFetchState](time.Hour)}
 	t.Cleanup(sm.smartFetchMap.StopCleaner)
@@ -92,3 +135,95 @@ func TestResetFailedSmartFetchState(t *testing.T) {
 	_, ok = sm.smartFetchMap.GetOk("system-1")
 	assert.True(t, ok, "expected successful smart fetch state to be preserved")
 }
+
+// countSmartDeviceRecords returns the number of smart_devices rows for the given system.
+func countSmartDeviceRecords(t *testing.T, app core.App, systemID string) []*core.Record {
+	t.Helper()
+	records, err := app.FindAllRecords("smart_devices", nil)
+	require.NoError(t, err)
+	var forSystem []*core.Record
+	for _, r := range records {
+		if r.GetString("system") == systemID {
+			forSystem = append(forSystem, r)
+		}
+	}
+	return forSystem
+}
+
+func TestSaveSmartDevices_RemovesStaleDevices(t *testing.T) {
+	sys, testApp := newTestSystemWithHub(t)
+
+	// first fetch reports two devices: sda (serial AAA) and sdb (serial BBB)
+	err := sys.saveSmartDevices(map[string]smart.SmartData{
+		"AAA": {SerialNumber: "AAA", DiskName: "sda", ModelName: "Disk A"},
+		"BBB": {SerialNumber: "BBB", DiskName: "sdb", ModelName: "Disk B"},
+	}, true)
+	require.NoError(t, err)
+
+	records := countSmartDeviceRecords(t, testApp, sys.Id)
+	require.Len(t, records, 2, "expected both devices to be saved")
+
+	var recordA *core.Record
+	for _, r := range records {
+		if r.GetString("serial") == "AAA" {
+			recordA = r
+		}
+	}
+	require.NotNil(t, recordA, "expected to find device AAA")
+	originalID := recordA.Id
+
+	deleteEvents := 0
+	testApp.OnRecordAfterDeleteSuccess("smart_devices").BindFunc(func(e *core.RecordEvent) error {
+		deleteEvents++
+		return e.Next()
+	})
+
+	// A complete refresh confirms that BBB is gone, so remove it through
+	// PocketBase and notify realtime subscribers.
+	err = sys.saveSmartDevices(map[string]smart.SmartData{
+		"AAA": {SerialNumber: "AAA", DiskName: "sda", ModelName: "Disk A", Temperature: 42},
+	}, true)
+	require.NoError(t, err)
+
+	records = countSmartDeviceRecords(t, testApp, sys.Id)
+	require.Len(t, records, 1, "expected stale device BBB to be removed")
+	assert.Equal(t, "AAA", records[0].GetString("serial"))
+	assert.Equal(t, originalID, records[0].Id, "expected existing device to be updated in place, not recreated")
+	assert.EqualValues(t, 42, records[0].GetInt("temp"))
+	assert.Equal(t, 1, deleteEvents, "expected PocketBase delete hooks to run")
+}
+
+func TestSaveSmartDevices_IncompleteDataDoesNotRemoveDevices(t *testing.T) {
+	sys, testApp := newTestSystemWithHub(t)
+
+	require.NoError(t, sys.saveSmartDevices(map[string]smart.SmartData{
+		"AAA": {SerialNumber: "AAA", DiskName: "sda"},
+		"BBB": {SerialNumber: "BBB", DiskName: "sdb"},
+	}, true))
+
+	// AAA was collected but BBB failed. The response is useful for updating AAA,
+	// but it is not authoritative enough to remove BBB.
+	require.NoError(t, sys.saveSmartDevices(map[string]smart.SmartData{
+		"AAA": {SerialNumber: "AAA", DiskName: "sda", Temperature: 42},
+	}, false))
+
+	assert.Len(t, countSmartDeviceRecords(t, testApp, sys.Id), 2)
+	recordA, err := testApp.FindRecordById("smart_devices", makeStableHashId(sys.Id, "AAA"))
+	require.NoError(t, err)
+	assert.EqualValues(t, 42, recordA.GetInt("temp"))
+}
+
+func TestSaveSmartDevices_EmptyDataIsNoop(t *testing.T) {
+	sys, testApp := newTestSystemWithHub(t)
+
+	err := sys.saveSmartDevices(map[string]smart.SmartData{
+		"AAA": {SerialNumber: "AAA", DiskName: "sda"},
+	}, true)
+	require.NoError(t, err)
+
+	err = sys.saveSmartDevices(map[string]smart.SmartData{}, true)
+	require.NoError(t, err)
+
+	records := countSmartDeviceRecords(t, testApp, sys.Id)
+	assert.Len(t, records, 1, "empty fetch result should not delete existing devices")
+}