Move component discovery to registry and run at startup (#88)

Author: joshuadavidthomas

CHANGELOG.md

@@ -21,6 +21,7 @@ and this project attempts to adhere to [Semantic Versioning](https://semver.org/
 ### Changed
 
 - **Internal**: Consolidated Component and Asset registries into a single `ComponentRegistry`.
+- **Internal**: Added component discovery at app startup instead of on-demand in the template loader.
 
 ## [0.7.2]
 

src/django_bird/apps.py

@@ -12,6 +12,8 @@ class DjangoBirdAppConfig(AppConfig):
 
     @override
     def ready(self):
+        from django_bird.components import components
         from django_bird.conf import app_settings
 
         app_settings.autoconfigure()
+        components.discover_components()

src/django_bird/components.py

@@ -8,10 +8,12 @@
 from cachetools import LRUCache
 from django.conf import settings
 from django.template.backends.django import Template as DjangoTemplate
+from django.template.exceptions import TemplateDoesNotExist
 from django.template.loader import select_template
 
 from django_bird.staticfiles import Asset
 
+from .conf import app_settings
 from .staticfiles import AssetType
 from .templates import get_template_names
 
@@ -49,6 +51,32 @@ class ComponentRegistry:
     def __init__(self, maxsize: int = 100):
         self._components: LRUCache[str, Component] = LRUCache(maxsize=maxsize)
 
+    def discover_components(self) -> None:
+        template_dirs = [dir for config in settings.TEMPLATES for dir in config["DIRS"]]
+
+        component_dirs = [
+            Path(template_dir) / component_dir
+            for template_dir in template_dirs
+            for component_dir in app_settings.COMPONENT_DIRS + ["bird"]
+        ]
+
+        for component_dir in component_dirs:
+            if not component_dir.is_dir():
+                continue
+
+            for component_path in component_dir.iterdir():
+                if component_path.is_dir():
+                    component_name = component_path.name
+                elif component_path.suffix == ".html":
+                    component_name = component_path.stem
+                else:
+                    continue
+
+                try:
+                    self.get_component(component_name)
+                except TemplateDoesNotExist:
+                    continue
+
     def clear(self) -> None:
         """Clear the registry. Mainly useful for testing."""
         self._components.clear()

src/django_bird/loader.py

@@ -38,7 +38,7 @@ def get_contents(self, origin: Origin) -> str:
         template = Template(contents, origin=origin, engine=self.engine)
         context = Context()
         with context.bind_template(template):
-            self._scan_for_components(template, context)
+            self._ensure_components_loaded(template, context)
 
         cache_key = f"bird_component_{hashlib.md5(contents.encode()).hexdigest()}"
         compiled = cache.get(cache_key)
@@ -47,7 +47,10 @@ def get_contents(self, origin: Origin) -> str:
             cache.set(cache_key, compiled, timeout=None)
         return compiled
 
-    def _scan_for_components(self, node: Template | Node, context: Context) -> None:
+    def _ensure_components_loaded(
+        self, node: Template | Node, context: Context
+    ) -> None:
+        """Ensure all components used in the template are loaded."""
         if isinstance(node, BirdNode):
             components.get_component(node.name)
 
@@ -60,12 +63,12 @@ def _scan_for_components(self, node: Template | Node, context: Context) -> None:
 
             if isinstance(child, ExtendsNode):
                 parent_template = child.get_parent(context)
-                self._scan_for_components(parent_template, context)
+                self._ensure_components_loaded(parent_template, context)
 
             if isinstance(child, IncludeNode):
                 template_name = child.template.token.strip("'\"")
                 included_template = self.engine.get_template(template_name)
-                self._scan_for_components(included_template, context)
+                self._ensure_components_loaded(included_template, context)
 
             if hasattr(child, "nodelist"):
-                self._scan_for_components(child, context)
+                self._ensure_components_loaded(child, context)

tests/conftest.py

@@ -1,5 +1,6 @@
 from __future__ import annotations
 
+import contextlib
 import logging
 import re
 from pathlib import Path
@@ -71,6 +72,18 @@ def override_templates_settings(templates_dir):
         yield
 
 
+@pytest.fixture
+def override_app_settings():
+    from django_bird.conf import DJANGO_BIRD_SETTINGS_NAME
+
+    @contextlib.contextmanager
+    def _override_app_settings(**kwargs):
+        with override_settings(**{DJANGO_BIRD_SETTINGS_NAME: {**kwargs}}):
+            yield
+
+    return _override_app_settings
+
+
 @pytest.fixture
 def create_bird_dir(templates_dir):
     def func(name):

tests/test_apps.py

@@ -0,0 +1,20 @@
+from __future__ import annotations
+
+from django.apps import apps
+
+from django_bird.components import components
+
+
+def test_ready_scans_components(create_bird_template):
+    create_bird_template("button", "<button>Click me</button>")
+    create_bird_template("alert", "<div>Alert</div>")
+
+    components.clear()
+
+    assert "button" not in components._components
+    assert "alert" not in components._components
+
+    apps.get_app_config("django_bird").ready()
+
+    assert "button" in components._components
+    assert "alert" in components._components

tests/test_components.py

@@ -91,6 +91,52 @@ class TestComponentRegistry:
     def registry(self):
         return ComponentRegistry(maxsize=2)
 
+    def test_initialize_loads_components(
+        self, registry, create_bird_template, settings
+    ):
+        create_bird_template("button", "<button>Click me</button>")
+        create_bird_template("alert", "<div>Alert</div>")
+
+        registry.discover_components()
+
+        assert "button" in registry._components
+        assert "alert" in registry._components
+
+    def test_initialize_loads_assets(
+        self, registry, create_bird_template, create_bird_asset
+    ):
+        template = create_bird_template("button", "<button>Click me</button>")
+        create_bird_asset(template, ".button { color: red; }", "css")
+        create_bird_asset(template, "console.log('button');", "js")
+
+        registry.discover_components()
+
+        component = registry._components["button"]
+        assert len(component.assets) == 2
+
+    def test_initialize_with_custom_dirs(
+        self, registry, create_bird_template, override_app_settings
+    ):
+        create_bird_template(
+            "button", "<button>Click me</button>", bird_dir_name="components"
+        )
+
+        with override_app_settings(COMPONENT_DIRS=["components"]):
+            registry.discover_components()
+
+        assert "button" in registry._components
+
+    def test_initialize_handles_missing_dirs(self, registry, settings):
+        settings.COMPONENT_DIRS = ["nonexistent"]
+
+        registry.discover_components()
+
+    def test_initialize_handles_invalid_components(self, registry, tmp_path, settings):
+        component_dir = tmp_path / "bird" / "invalid"
+        component_dir.mkdir(parents=True)
+
+        registry.discover_components()
+
     def test_get_component_caches(self, registry, create_bird_template):
         create_bird_template(name="button", content="<button>Click me</button>")
 

tests/test_loader.py

@@ -74,7 +74,7 @@ def test_render_template(template_name):
         (Template("{% bird button %}{% bird button %}{% endbird %}{% endbird %}"), 1),
     ],
 )
-def test_scan_for_components(
+def test_ensure_components_loaded(
     node, expected_count, create_bird_template, create_bird_asset
 ):
     button = create_bird_template("button", "<button>Click me</button>")
@@ -84,6 +84,6 @@ def test_scan_for_components(
     loader = BirdLoader(Engine.get_default())
     context = Context()
 
-    loader._scan_for_components(node, context)
+    loader._ensure_components_loaded(node, context)
 
     assert len(components._components) == expected_count