Handle empty dashboard metrics safely

dist/urbm-2026.07.13.r009-x86_64-1.txz.sha256

@@ -1 +0,0 @@
-11efad3fbbe8f71092177ef912353d0c0f733b66974af18aba83a0275c2c22f9  urbm-2026.07.13.r009-x86_64-1.txz

dist/urbm-2026.07.13.r010-x86_64-1.txz.sha256

@@ -0,0 +1 @@
+3f655152c8e0875711c8b02036b05b1a163227a658fe6b2e4bf91397270a7f48  urbm-2026.07.13.r010-x86_64-1.txz

dist/urbm.plg

@@ -2,13 +2,17 @@
 <!DOCTYPE PLUGIN [
 <!ENTITY name "urbm">
 <!ENTITY author "Michael Roll">
-<!ENTITY version "2026.07.13.r009">
+<!ENTITY version "2026.07.13.r010">
 <!ENTITY pluginURL "https://git.casaderoll.de/michael/URBM/raw/branch/main/dist/urbm.plg">
 <!ENTITY packageURL "https://git.casaderoll.de/michael/URBM/raw/branch/main/dist/urbm-&version;-x86_64-1.txz">
-<!ENTITY packageSHA256 "11efad3fbbe8f71092177ef912353d0c0f733b66974af18aba83a0275c2c22f9">
+<!ENTITY packageSHA256 "3f655152c8e0875711c8b02036b05b1a163227a658fe6b2e4bf91397270a7f48">
 ]>
 <PLUGIN name="&name;" author="&author;" version="&version;" pluginURL="&pluginURL;" min="7.0.0" support="https://git.casaderoll.de/michael/URBM/issues" icon="urbm.png">
   <CHANGES>
+### 2026.07.13.r010
+- Return an empty JSON array instead of `null` when no dashboard backup measurements exist yet.
+- Make the WebGUI tolerate empty or invalid metric responses so the rest of the interface remains available.
+
 ### 2026.07.13.r009
 - Store completed-backup chart measurements independently in `backup-metrics.json` so clearing activities no longer erases the dashboard history.
 - Migrate existing successful backup runs into the new durable metric history automatically and expose them through a dedicated read-only API.

internal/service/safety_test.go

@@ -2,6 +2,7 @@ package service
 
 import (
 	"context"
+	"encoding/json"
 	"os"
 	"path/filepath"
 	"testing"
@@ -11,6 +12,17 @@ import (
 	"git.casaderoll.de/michael/urbm/internal/store"
 )
 
+func TestEmptyBackupMetricsEncodeAsJSONArray(t *testing.T) {
+	s := &Service{}
+	encoded, err := json.Marshal(s.BackupMetrics())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(encoded) != "[]" {
+		t.Fatalf("empty backup metrics JSON = %s", encoded)
+	}
+}
+
 func TestRepositoryLockHonorsContextCancellation(t *testing.T) {
 	s := &Service{repositoryLocks: map[string]chan struct{}{}}
 	repo := model.Repository{Type: model.RepositoryLocal, Location: "/repo"}

internal/service/service.go

@@ -134,7 +134,9 @@ func (s *Service) Runs() []model.Run    { return s.queue.Snapshot() }
 func (s *Service) BackupMetrics() []model.BackupMetric {
 	s.metricsMu.RLock()
 	defer s.metricsMu.RUnlock()
-	return append([]model.BackupMetric(nil), s.backupMetrics...)
+	metrics := make([]model.BackupMetric, len(s.backupMetrics))
+	copy(metrics, s.backupMetrics)
+	return metrics
 }
 func (s *Service) Logs() map[string]any {
 	return map[string]any{

plugin/urbm.plg

@@ -2,13 +2,17 @@
 <!DOCTYPE PLUGIN [
 <!ENTITY name "urbm">
 <!ENTITY author "Michael Roll">
-<!ENTITY version "2026.07.13.r009">
+<!ENTITY version "2026.07.13.r010">
 <!ENTITY pluginURL "https://git.casaderoll.de/michael/URBM/raw/branch/main/dist/urbm.plg">
 <!ENTITY packageURL "https://git.casaderoll.de/michael/URBM/raw/branch/main/dist/urbm-&version;-x86_64-1.txz">
 <!ENTITY packageSHA256 "REPLACE_DURING_RELEASE">
 ]>
 <PLUGIN name="&name;" author="&author;" version="&version;" pluginURL="&pluginURL;" min="7.0.0" support="https://git.casaderoll.de/michael/URBM/issues" icon="urbm.png">
   <CHANGES>
+### 2026.07.13.r010
+- Return an empty JSON array instead of `null` when no dashboard backup measurements exist yet.
+- Make the WebGUI tolerate empty or invalid metric responses so the rest of the interface remains available.
+
 ### 2026.07.13.r009
 - Store completed-backup chart measurements independently in `backup-metrics.json` so clearing activities no longer erases the dashboard history.
 - Migrate existing successful backup runs into the new durable metric history automatically and expose them through a dedicated read-only API.

webgui/URBM.page

@@ -8,7 +8,7 @@ Tag="URBM Unraid Restic Backup Manager backup snapshots restore"
 ---
 <?php
 $pluginRoot = '/plugins/urbm';
-$urbmVersion = '2026.07.13.r009';
+$urbmVersion = '2026.07.13.r010';
 $urbmAssetVersion = preg_replace('/[^A-Za-z0-9]/', '', $urbmVersion);
 ?>
 <link rel="stylesheet" href="<?= $pluginRoot ?>/assets/urbm.css?v=<?= $urbmAssetVersion ?>">

webgui/assets/urbm.js

@@ -402,7 +402,7 @@
   async function load() {
     try {
       const [config, runs, backupMetrics, daemon] = await Promise.all([api('/v1/config'), api('/v1/runs'), api('/v1/backup-metrics'), api('/v1/health')]);
-      state.config = config; state.runs = newestRuns(runs); state.backupMetrics = backupMetrics;
+      state.config = config; state.runs = newestRuns(runs); state.backupMetrics = Array.isArray(backupMetrics) ? backupMetrics : [];
       health.textContent = `Daemon online (${daemon.version || 'unbekannt'})`; health.className = 'bu-health ok'; render();
     } catch (error) {
       health.textContent = 'Daemon nicht erreichbar'; health.className = 'bu-health bad';
@@ -1105,6 +1105,6 @@
   window.addEventListener('scroll', hideTooltip, true);
   window.addEventListener('resize', hideTooltip);
   enhanceTooltips(root);
-  setInterval(async()=>{ if(!state.config)return; try { const runs=newestRuns(await api('/v1/runs')); const changed=JSON.stringify(runs)!==JSON.stringify(state.runs); state.runs=runs; if(changed){ state.backupMetrics=await api('/v1/backup-metrics'); if(['dashboard','activity'].includes(state.view))render(); } }catch(_){ } },2000);
+  setInterval(async()=>{ if(!state.config)return; try { const runs=newestRuns(await api('/v1/runs')); const changed=JSON.stringify(runs)!==JSON.stringify(state.runs); state.runs=runs; if(changed){ const backupMetrics=await api('/v1/backup-metrics'); state.backupMetrics=Array.isArray(backupMetrics) ? backupMetrics : []; if(['dashboard','activity'].includes(state.view))render(); } }catch(_){ } },2000);
   load();
 })();