Fixes #19872: Display form validation errors for script execution

When script form validation fails (e.g., required fields excluded from
fieldsets), display error messages via Django's message framework instead
of failing silently. Error format: "field: error1, error2; field2: error".

netbox/extras/tests/test_views.py

@@ -1,11 +1,14 @@
 from django.contrib.contenttypes.models import ContentType
 from django.urls import reverse
+from django.test import tag
 
+from core.choices import ManagedFileRootPathChoices
 from core.events import *
 from core.models import ObjectType
 from dcim.models import DeviceType, Manufacturer, Site
 from extras.choices import *
 from extras.models import *
+from extras.scripts import Script as PythonClass, IntegerVar, BooleanVar
 from users.models import Group, User
 from utilities.testing import ViewTestCases, TestCase
 
@@ -897,3 +900,45 @@ class ScriptListViewTest(TestCase):
         response = self.client.get(url, {'embedded': 'true'})
         self.assertEqual(response.status_code, 200)
         self.assertTemplateUsed(response, 'extras/inc/script_list_content.html')
+
+
+class ScriptValidationErrorTest(TestCase):
+    user_permissions = ['extras.view_script', 'extras.run_script']
+
+    class TestScriptMixin:
+        bar = IntegerVar(min_value=0, max_value=30, default=30)
+
+    class TestScriptClass(TestScriptMixin, PythonClass):
+        class Meta:
+            name = 'Test script'
+            commit_default = False
+            fieldsets = (("Logging", ("debug_mode",)),)
+
+        debug_mode = BooleanVar(default=False)
+
+        def run(self, data, commit):
+            return "Complete"
+
+    @classmethod
+    def setUpTestData(cls):
+        module = ScriptModule.objects.create(file_root=ManagedFileRootPathChoices.SCRIPTS, file_path='test_script.py')
+        cls.script = Script.objects.create(module=module, name='Test script', is_executable=True)
+
+    def setUp(self):
+        super().setUp()
+        Script.python_class = property(lambda self: ScriptValidationErrorTest.TestScriptClass)
+
+    @tag('regression')
+    def test_script_validation_error_displays_message(self):
+        """Test that form validation errors are displayed to the user"""
+        from unittest.mock import patch
+
+        url = reverse('extras:script', kwargs={'pk': self.script.pk})
+
+        with patch('extras.views.get_workers_for_queue', return_value=['worker']):
+            response = self.client.post(url, {'debug_mode': 'true', '_commit': 'true'})
+
+        self.assertEqual(response.status_code, 200)
+        messages = list(response.context['messages'])
+        self.assertEqual(len(messages), 1)
+        self.assertEqual(str(messages[0]), "bar: This field is required.")

netbox/extras/views.py

@@ -1485,6 +1485,11 @@ class ScriptView(BaseScriptView):
             )
 
             return redirect('extras:script_result', job_pk=job.pk)
+        else:
+            messages.error(
+                request,
+                '; '.join(f"{field}: {', '.join(errors)}" for field, errors in form.errors.items())
+            )
 
         return render(request, 'extras/script.html', {
             'object': script,