From 490b337453100f397907c4e73ee23d15a5b56172 Mon Sep 17 00:00:00 2001
From: catborise <catborise@gmail.com>
Date: Tue, 6 Oct 2026 12:27:45 +0300
Subject: [PATCH] fix(instances): the VM page reloads only when the VM state
 changes

The VM page polls the VM state every 5 s and reloads when it differs
from the state the page was rendered with. Since the polling moved to
pollWhileVisible, that state was kept in a top-level "var status",
which is not a page variable but the browser's window.status. Where the
browser does not keep a value there, the poll compared the answer with
"" and reloaded the page every 5 s, back to its first tab.

The variable is now vm_status. A Node test runs the page's script with
a window.status that keeps nothing.
---
 instances/templates/instance.html |  5 +++--
 webvirtcloud/test_poll_js.py      | 31 +++++++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/instances/templates/instance.html b/instances/templates/instance.html
index 34c2aa4f..c5317690 100644
--- a/instances/templates/instance.html
+++ b/instances/templates/instance.html
@@ -652,11 +652,12 @@
 </script>
 <script>
     backgroundJobRunning = false;
-    var status = {{ instance.status|lower }};
+    // not "status": that is window.status, which the browser may not keep
+    var vm_status = {{ instance.status|lower }};
     var status_poll = pollWhileVisible(5000, function () {
         return $.getJSON("{% url 'instances:status' instance.id %}");
     }, function get_status(data) {
-        if (data['status'] != status && !backgroundJobRunning) {
+        if (data['status'] != vm_status && !backgroundJobRunning) {
             window.location.reload()
         }
     });
diff --git a/webvirtcloud/test_poll_js.py b/webvirtcloud/test_poll_js.py
index eb8553b9..8bf61298 100644
--- a/webvirtcloud/test_poll_js.py
+++ b/webvirtcloud/test_poll_js.py
@@ -1,6 +1,8 @@
 """Pages poll the server through static/js/poll.js: one request at a time,
 none while the page is hidden. Its behaviour is checked with Node."""
 
+import json
+import re
 import shutil
 import subprocess
 import unittest
@@ -29,3 +31,32 @@ class PollTestCase(unittest.TestCase):
                 source = (BASE / template).read_text()
                 self.assertNotIn("setInterval", source)
                 self.assertIn("pollWhileVisible(", source)
+
+    @unittest.skipUnless(shutil.which("node"), "node is not installed")
+    def test_the_vm_page_reloads_only_when_the_state_changes(self):
+        # "status" is a property of the browser's window: a page variable of
+        # that name holds what the browser makes of it (a string, or nothing)
+        source = (BASE / "instances/templates/instance.html").read_text()
+        script = re.search(r"<script>\s*(backgroundJobRunning = false;.*?)</script>", source, re.S).group(1)
+        script = script.replace("{{ instance.status|lower }}", "1").replace(
+            "{% url 'instances:status' instance.id %}", "/instances/1/status/"
+        )
+        js = """
+        const vm = require("vm");
+        const results = {};
+        for (const answer of [1, 5]) {
+            let reloads = 0;
+            const page = {
+                pollWhileVisible: (interval, request, onData) => { onData({status: answer}); return {stop() {}}; },
+                $: () => ({submit() {}}),
+            };
+            page.window = {location: {reload: () => reloads++}};
+            Object.defineProperty(page, "status", {get: () => "", set: () => {}});
+            vm.runInNewContext(SCRIPT, vm.createContext(page));
+            results[answer] = reloads;
+        }
+        console.log(JSON.stringify(results));
+        """.replace("SCRIPT", json.dumps(script))
+        out = subprocess.run(["node", "-e", js], capture_output=True, text=True, timeout=30)
+        self.assertEqual(out.returncode, 0, out.stderr)
+        self.assertEqual(json.loads(out.stdout), {"1": 0, "5": 1})