Add tests

tests/tests/test_context_modifiers.py

@@ -0,0 +1,131 @@
+from unittest import mock
+
+from django.core.exceptions import ImproperlyConfigured
+from django.http import HttpRequest
+from django.test import SimpleTestCase
+
+from pattern_library import register_context_modifier
+from pattern_library.context_modifiers import registry
+from pattern_library.utils import render_pattern
+
+
+def accepts_context_only(context):
+    pass
+
+
+def accepts_request_only(request):
+    pass
+
+
+def modifier_1(context, request):
+    context["foo"] = "foo"
+
+
+def modifier_2(context, request):
+    context["foo"] = "bar"
+
+
+def modifier_3(context, request):
+    context["beep"] = "boop"
+
+
+atom_template = "patterns/atoms/test_atom/test_atom.html"
+
+
+class ContextModifierTestCase(SimpleTestCase):
+
+    maxDiff = None
+
+    def setUp(self):
+        registry.clear()
+
+    def tearDown(self):
+        registry.clear()
+
+    def test_validation(self):
+        with self.assertRaisesRegex(ImproperlyConfigured, "must be callables"):
+            registry.register(0, template=atom_template)
+        with self.assertRaisesRegex(
+            ImproperlyConfigured, "must accept a 'request' argument"
+        ):
+            registry.register(accepts_context_only, template=atom_template)
+        with self.assertRaisesRegex(
+            ImproperlyConfigured, "must accept a 'context' argument"
+        ):
+            registry.register(accepts_request_only, template=atom_template)
+
+    def test_registred_without_ordering(self):
+        registry.register(modifier_1, template=atom_template)
+        registry.register(modifier_2, template=atom_template)
+        registry.register(modifier_3, template=atom_template)
+
+        result = registry.get_for_template(atom_template)
+        self.assertEqual(
+            result,
+            [
+                modifier_1,
+                modifier_2,
+                modifier_3,
+            ],
+        )
+
+    def test_registered_with_ordering(self):
+        registry.register(modifier_1, template=atom_template, order=10)
+        registry.register(modifier_2, template=atom_template, order=5)
+        registry.register(modifier_3, template=atom_template, order=0)
+
+        result = registry.get_for_template(atom_template)
+        self.assertEqual(
+            result,
+            [
+                modifier_3,
+                modifier_2,
+                modifier_1,
+            ],
+        )
+
+    def test_registered_via_decorator(self):
+        @register_context_modifier(order=100)
+        def func_a(context, request):
+            pass
+
+        @register_context_modifier(order=50)
+        def func_b(context, request):
+            pass
+
+        @register_context_modifier(template=atom_template)
+        def func_c(context, request):
+            pass
+
+        @register_context_modifier(template="different_template.html", order=1)
+        def func_x(context, request):  # NOQA
+            pass
+
+        result = registry.get_for_template(atom_template)
+        self.assertEqual(
+            result,
+            [
+                func_c,
+                func_b,
+                func_a,
+            ],
+        )
+
+    @mock.patch("pattern_library.utils.render_to_string")
+    def test_applied_by_render_pattern(self, render_to_string):
+        request = HttpRequest()
+        registry.register(modifier_1)
+        registry.register(modifier_2, template=atom_template)
+        registry.register(modifier_3, template=atom_template)
+
+        render_pattern(request, atom_template)
+        render_to_string.assert_called_with(
+            atom_template,
+            request=request,
+            context={
+                "atom_var": "atom_var value from test_atom.yaml",
+                "__pattern_library_view": True,
+                "foo": "bar",
+                "beep": "boop",
+            },
+        )