Fix error handling in template tag (#138)

solo/templatetags/solo_tags.py

@@ -19,8 +19,9 @@ def get_solo(model_path: str) -> SingletonModel:
                 "Received '{model_path}'."
             ).format(model_path=model_path)
         )
-    model_class: type[SingletonModel] = apps.get_model(app_label, model_name)
-    if not model_class:
+    try:
+        model_class: type[SingletonModel] = apps.get_model(app_label, model_name)
+    except LookupError:
         raise template.TemplateSyntaxError(
             _("Could not get the model name '{model}' from the application named '{app}'").format(
                 model=model_name, app=app_label

solo/tests/tests.py

@@ -1,6 +1,6 @@
 from django.core.cache import caches
 from django.core.files.uploadedfile import SimpleUploadedFile
-from django.template import Context, Template
+from django.template import Context, Template, TemplateSyntaxError
 from django.test import TestCase
 from django.test.utils import override_settings
 
@@ -16,6 +16,18 @@ def setUp(self):
             "{{ site_config.site_name }}"
             "{{ site_config.file.url }}"
         )
+        self.template_invalid_app = Template(
+            "{% load solo_tags %}"
+            '{% get_solo "invalid_app.SiteConfiguration" as site_config  %}'
+            "{{ site_config.site_name }}"
+            "{{ site_config.file.url }}"
+        )
+        self.template_invalid_model = Template(
+            "{% load solo_tags %}"
+            '{% get_solo "tests.InvalidModel" as site_config  %}'
+            "{{ site_config.site_name }}"
+            "{{ site_config.file.url }}"
+        )
         self.cache = caches["default"]
         self.cache_key = SiteConfiguration.get_cache_key()
         self.cache.clear()
@@ -96,6 +108,14 @@ def test_cache_prefix_overriding(self):
         prefix = key.partition(":")[0]
         self.assertEqual(prefix, "other")
 
+    def test_template_tag_invalid_app_name(self):
+        with self.assertRaises(TemplateSyntaxError):
+            self.template_invalid_app.render(Context())
+
+    def test_template_invalid_model_name(self):
+        with self.assertRaises(TemplateSyntaxError):
+            self.template_invalid_model.render(Context())
+
 
 class SingletonWithExplicitIdTest(TestCase):
     def setUp(self):