feat: add fragment support to entrypoints

src/validate_pyproject/plugins/__init__.py

@@ -55,9 +55,10 @@ def fragment(self) -> str:
 
 
 class PluginWrapper:
-    def __init__(self, tool: str, load_fn: "Plugin"):
+    def __init__(self, tool: str, load_fn: "Plugin", *, fragment: str = ""):
         self._tool = tool
         self._load_fn = load_fn
+        self._fragment = fragment
 
     @property
     def id(self) -> str:
@@ -73,7 +74,7 @@ def schema(self) -> "Schema":
 
     @property
     def fragment(self) -> str:
-        return ""
+        return self._fragment
 
     @property
     def help_text(self) -> str:
@@ -83,7 +84,10 @@ def help_text(self) -> str:
         return Template(tpl).safe_substitute(tool=self.tool, id=self.id)
 
     def __repr__(self) -> str:
-        return f"{self.__class__.__name__}({self.tool!r}, {self.id})"
+        args = [repr(self.tool), self.id]
+        if self.fragment:
+            args.append(f"fragment={self.fragment!r}")
+        return f"{self.__class__.__name__}({', '.join(args)})"
 
 
 if typing.TYPE_CHECKING:
@@ -118,7 +122,8 @@ def load_from_entry_point(entry_point: EntryPoint) -> PluginWrapper:
     """Carefully load the plugin, raising a meaningful message in case of errors"""
     try:
         fn = entry_point.load()
-        return PluginWrapper(entry_point.name, fn)
+        fragment = getattr(fn, "fragment", "")
+        return PluginWrapper(entry_point.name, fn, fragment=fragment)
     except Exception as ex:
         raise ErrorLoadingPlugin(entry_point=entry_point) from ex
 

tests/test_plugins.py

@@ -6,6 +6,7 @@
 
 import pytest
 
+import validate_pyproject.api
 from validate_pyproject import plugins
 from validate_pyproject.plugins import ENTRYPOINT_GROUP, ErrorLoadingPlugin
 
@@ -31,6 +32,20 @@ def test_load_from_entry_point__error():
         plugins.load_from_entry_point(fake)
 
 
+def test_load_from_entry_point_fragment(monkeypatch):
+    monkeypatch.setattr(
+        validate_pyproject.api.load_builtin_plugin,
+        "fragment",
+        "/properties/tool/properties",
+        raising=False,
+    )
+    entry = "validate_pyproject.api:load_builtin_plugin"
+    real = EntryPoint("cibuildwheel", entry, ENTRYPOINT_GROUP)
+    p = plugins.load_from_entry_point(real)
+    assert p.fragment == "/properties/tool/properties"
+    assert p.tool == "cibuildwheel"
+
+
 def is_entry_point(ep):
     return all(hasattr(ep, attr) for attr in ("name", "load"))