diff --git a/plinth/modules/diagnostics/tests/test_diagnostics.py b/plinth/modules/diagnostics/tests/test_diagnostics.py
new file mode 100644
index 000000000..f056167aa
--- /dev/null
+++ b/plinth/modules/diagnostics/tests/test_diagnostics.py
@@ -0,0 +1,58 @@
+# SPDX-License-Identifier: AGPL-3.0-or-later
+"""Tests for Diagnostics app functions."""
+
+from collections import OrderedDict
+from unittest.mock import patch
+
+from plinth.app import App, Info
+from plinth.modules.diagnostics import get_results
+
+
+class AppTest(App):
+    """Sample App for testing."""
+    app_id = 'test-app'
+
+    def __init__(self):
+        super().__init__()
+        info = Info('test-app', 1)
+        self.add(info)
+
+
+def test_get_results():
+    """Test getting the diagnostics results."""
+    var = 'plinth.modules.diagnostics.current_results'
+    with patch(var, {}):
+        assert get_results() == {'progress_percentage': 100, 'results': {}}
+
+    with patch(var, {
+            'apps': [],
+            'results': OrderedDict(),
+            'progress_percentage': 0
+    }):
+        assert get_results() == {
+            'apps': [],
+            'results': {},
+            'progress_percentage': 0
+        }
+
+    _ = AppTest()
+    results = OrderedDict({
+        'test-app': {
+            'id': 'test-app',
+            'diagnosis': [],
+            'exception': None,
+            'show_rerun_setup': False
+        }
+    })
+    with patch(
+            var, {
+                'apps': [('test-app', AppTest)],
+                'results': results,
+                'progress_percentage': 0
+            }):
+        results['test-app'].update({'name': 'test-app'})
+        assert get_results() == {
+            'apps': [('test-app', AppTest)],
+            'results': results,
+            'progress_percentage': 0
+        }