Allow metadata hooks to run when project.dynamic is empty

backend/src/hatchling/metadata/core.py

@@ -191,21 +191,20 @@ def core(self) -> CoreMetadata:
                     self._version = self._get_version(metadata)
                     self.core_raw_metadata["version"] = self.version
 
-                if metadata.dynamic:
-                    for metadata_hook in metadata_hooks.values():
-                        metadata_hook.update(self.core_raw_metadata)
-                        metadata.add_known_classifiers(metadata_hook.get_known_classifiers())
-
-                    new_fields = set(self.core_raw_metadata) - static_fields
-                    for new_field in new_fields:
-                        if new_field in metadata.dynamic:
-                            metadata.dynamic.remove(new_field)
-                        else:
-                            message = (
-                                f"The field `{new_field}` was set dynamically and therefore must be "
-                                f"listed in `project.dynamic`"
-                            )
-                            raise ValueError(message)
+                for metadata_hook in metadata_hooks.values():
+                    metadata_hook.update(self.core_raw_metadata)
+                    metadata.add_known_classifiers(metadata_hook.get_known_classifiers())
+
+                new_fields = set(self.core_raw_metadata) - static_fields
+                for new_field in new_fields:
+                    if new_field in metadata.dynamic:
+                        metadata.dynamic.remove(new_field)
+                    else:
+                        message = (
+                            f"The field `{new_field}` was set dynamically and therefore must be "
+                            f"listed in `project.dynamic`"
+                        )
+                        raise ValueError(message)
 
             self._core = metadata
 

tests/backend/metadata/test_core.py

@@ -1497,6 +1497,34 @@ def update(self, metadata):
         ):
             _ = metadata.core
 
+    def test_custom_no_dynamic(self, temp_dir, helpers):
+        metadata = ProjectMetadata(
+            str(temp_dir),
+            PluginManager(),
+            {
+                "project": {"name": "foo", "version": "1.0.0", "dependencies": ["bar==1.0"]},
+                "tool": {"hatch": {"metadata": {"hooks": {"custom": {}}}}},
+            },
+        )
+
+        file_path = temp_dir / DEFAULT_BUILD_SCRIPT
+        file_path.write_text(
+            helpers.dedent(
+                """
+                from hatchling.metadata.plugin.interface import MetadataHookInterface
+
+                class CustomHook(MetadataHookInterface):
+                    def update(self, metadata):
+                        metadata['dependencies'] = ['bar==2.0']
+                """
+            )
+        )
+
+        assert "custom" in metadata.hatch.metadata.hooks
+        assert metadata.core.name == "foo"
+        assert metadata.core.version == "1.0.0"
+        assert metadata.core.dependencies == ["bar==2.0"]
+
 
 class TestHatchPersonalProjectConfigFile:
     def test_correct(self, temp_dir, helpers):