Added action registry

- Accessing the registry ensures the built-in actions are loaded.

Author: coordt

generate_changelog/pipeline.py

@@ -1,12 +1,7 @@
 """Simple pipeline workflow processing."""
 from typing import Any, Callable, Optional, Union
 
-from dataclasses import dataclass, field
-
-from generate_changelog.configuration import StrOrCallable
-from generate_changelog.processors import BUILT_INS, load_builtins
-
-load_builtins()
+from generate_changelog.processors import BUILT_INS
 
 
 def noop_func(**kwargs):

generate_changelog/processors/__init__.py

@@ -1,8 +1,41 @@
 """Processing module for changelog generation."""
-
 from typing import Callable, Union
 
-BUILT_INS = {}
+from collections import UserDict
+
+
+class Registry(UserDict):
+    """
+    Built-in action registry.
+
+    This allows setting keys normally. When getting a key, it makes sure the
+    appropriate modules are imported to fill the internal dictionary before
+    getting the key.
+    """
+
+    def __init__(self, initialdata=None):
+        super().__init__(initialdata)
+        self._loaded = False
+
+    def __getitem__(self, key):
+        """Make sure the built-in actions are loaded."""
+        if not self._loaded:
+            self.load_builtins()
+        return super().__getitem__(key)
+
+    def load_builtins(self):
+        """Import all submodules so the decorated functions get registered."""
+        import importlib
+
+        importlib.import_module(".text_processing", "generate_changelog.processors")
+        importlib.import_module(".file_processing", "generate_changelog.processors")
+        importlib.import_module(".shell", "generate_changelog.processors")
+        importlib.import_module(".metadata", "generate_changelog.processors")
+
+        self._loaded = True
+
+
+BUILT_INS = Registry()
 """The registered actions that are considered to be built-in."""
 
 
@@ -21,13 +54,3 @@ def inner(f: Callable) -> Callable:
     else:
         name = function_or_name
         return inner
-
-
-def load_builtins():
-    """Import all submodules so the decorated functions get registered."""
-    import importlib
-
-    importlib.import_module(".text_processing", "generate_changelog.processors")
-    importlib.import_module(".file_processing", "generate_changelog.processors")
-    importlib.import_module(".shell", "generate_changelog.processors")
-    importlib.import_module(".metadata", "generate_changelog.processors")

generate_changelog/templating.py

@@ -13,12 +13,8 @@
 from generate_changelog.configuration import Configuration, get_config
 from generate_changelog.lazy import LazyObject
 from generate_changelog.pipeline import pipeline_factory
-from generate_changelog.processors import load_builtins
 from generate_changelog.processors.metadata import MetadataCollector
 
-load_builtins()
-
-
 default_env = LazyObject(
     lambda: Environment(
         loader=ChoiceLoader([FileSystemLoader(get_config().template_dirs), PackageLoader("generate_changelog")]),

test/processors/test_registry.py

@@ -0,0 +1,14 @@
+"""Tests of the registry system."""
+
+from generate_changelog.processors import Registry
+
+
+def test_registry_get_key_loads_builtins():
+    """Getting a key from the registry should load the built-ins."""
+    r = Registry()
+    r["new_attr"] = "foo"
+    assert r.data["new_attr"] == "foo"
+    assert "new_attr" in r
+    assert not r._loaded
+    assert r["new_attr"] == "foo"
+    assert r._loaded