Merge pull request #30 from tbrlpld/remove-context-none-guard

Remove context `None` guard exception

CHANGELOG.md

@@ -17,7 +17,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Removed
 
-- ...
+- The `TypeError` that was raised in `render_html` when `get_context_data` returned `None` was removed. This change is Wagtail-compatible. ([#30](https://github.com/tbrlpld/laces/pull/30))
 
 ## [0.1.1] - 2024-02-10
 

laces/components.py

@@ -45,9 +45,6 @@ def render_html(
         `django.utils.safestring.SafeString` instance.
         """
         context_data = self.get_context_data(parent_context)
-        if context_data is None:
-            raise TypeError("Expected a dict from get_context_data, got None")
-
         template = get_template(self.template_name)
         return template.render(context_data)
 

laces/tests/test_components.py

@@ -152,21 +152,30 @@ def get_context_data(
 
         self.assertEqual(result, "Hello World")
 
-    def test_render_html_when_get_context_data_returns_None(self) -> None:
+    def test_render_html_when_get_context_data_returns_none(self) -> None:
         """
         Test `render_html` method when `get_context_data` returns `None`.
 
-        The `render_html` method raises a `TypeError` when `None` is returned from
-        `get_context_method`. This behavior was present when the class was extracted
-        from Wagtail. It is not totally clear why this specific check is needed. By
-        default, the `get_context_data` method provides and empty dict. If an override
-        wanted to `get_context_data` return `None`, it should be expected that no
-        context data is available during rendering. The underlying `template.render`
-        method does not seem to be ok with `None` as the provided context.
+        Originally, the `render_html` method explicitly raised a `TypeError` when
+        `None` was returned from `get_context_method`.
+
+        I was not able to find out why this check was put in place. The usage of
+        components in Wagtail does not reveal any issues when the raising of the
+        exception is removed. Also, the following template rendering (with
+        `django.template.base.Template.render`) works just fine with the context being
+        `None`.
+
+        It seems therefore safe to assume that this was a left-over without much current
+        need.
+
+        This test is in place to prove that a component can behave as expected when the
+        `get_context_data` method returns `None`.
         """
 
         # -----------------------------------------------------------------------------
         class ExampleComponent(Component):
+            template_name = self.example_template_name
+
             def get_context_data(
                 self,
                 parent_context: "Optional[RenderContext]" = None,
@@ -175,9 +184,11 @@ def get_context_data(
                 return None
 
         # -----------------------------------------------------------------------------
+        self.set_example_template_content("Hello")
+
+        result = ExampleComponent().render_html()
 
-        with self.assertRaises(TypeError):
-            ExampleComponent().render_html()
+        self.assertEqual(result, "Hello")
 
     def test_media_defined_through_nested_class(self) -> None:
         """