Implement minimal versions of metadata preparation methods (#466)

Author: ofek

backend/src/hatchling/build.py

@@ -31,6 +31,24 @@ def get_requires_for_build_wheel(config_settings=None):
     return builder.config.dependencies
 
 
+def prepare_metadata_for_build_wheel(metadata_directory, config_settings=None):
+    """
+    https://peps.python.org/pep-0517/#prepare-metadata-for-build-wheel
+    """
+    from hatchling.builders.wheel import WheelBuilder
+
+    builder = WheelBuilder(os.getcwd())
+
+    directory = os.path.join(metadata_directory, f'{builder.artifact_project_id}.dist-info')
+    if not os.path.isdir(directory):
+        os.mkdir(directory)
+
+    with open(os.path.join(directory, 'METADATA'), 'w', encoding='utf-8') as f:
+        f.write(builder.config.core_metadata_constructor(builder.metadata))
+
+    return os.path.basename(directory)
+
+
 def build_wheel(wheel_directory, config_settings=None, metadata_directory=None):
     """
     https://peps.python.org/pep-0517/#build-wheel
@@ -51,6 +69,28 @@ def get_requires_for_build_editable(config_settings=None):
     return builder.config.dependencies
 
 
+def prepare_metadata_for_build_editable(metadata_directory, config_settings=None):
+    """
+    https://peps.python.org/pep-0660/#prepare-metadata-for-build-editable
+    """
+    from hatchling.builders.wheel import EDITABLES_MINIMUM_VERSION, WheelBuilder
+
+    builder = WheelBuilder(os.getcwd())
+
+    directory = os.path.join(metadata_directory, f'{builder.artifact_project_id}.dist-info')
+    if not os.path.isdir(directory):
+        os.mkdir(directory)
+
+    extra_dependencies = []
+    if not builder.config.dev_mode_dirs and builder.config.dev_mode_exact:
+        extra_dependencies.append(f'editables~={EDITABLES_MINIMUM_VERSION}')
+
+    with open(os.path.join(directory, 'METADATA'), 'w', encoding='utf-8') as f:
+        f.write(builder.config.core_metadata_constructor(builder.metadata, extra_dependencies=extra_dependencies))
+
+    return os.path.basename(directory)
+
+
 def build_editable(wheel_directory, config_settings=None, metadata_directory=None):
     """
     https://peps.python.org/pep-0660/#build-editable

backend/src/hatchling/ouroboros.py

@@ -95,8 +95,48 @@ def get_requires_for_build_wheel(config_settings=None):
     return CONFIG['project']['dependencies']
 
 
+def prepare_metadata_for_build_wheel(metadata_directory, config_settings=None):
+    """
+    https://peps.python.org/pep-0517/#prepare-metadata-for-build-wheel
+    """
+    from hatchling.builders.wheel import WheelBuilder
+
+    builder = WheelBuilder(os.getcwd(), config=CONFIG)
+
+    directory = os.path.join(metadata_directory, f'{builder.artifact_project_id}.dist-info')
+    if not os.path.isdir(directory):
+        os.mkdir(directory)
+
+    with open(os.path.join(directory, 'METADATA'), 'w', encoding='utf-8') as f:
+        f.write(builder.config.core_metadata_constructor(builder.metadata))
+
+    return os.path.basename(directory)
+
+
 def get_requires_for_build_editable(config_settings=None):
     """
     https://peps.python.org/pep-0660/#get-requires-for-build-editable
     """
     return CONFIG['project']['dependencies']
+
+
+def prepare_metadata_for_build_editable(metadata_directory, config_settings=None):
+    """
+    https://peps.python.org/pep-0660/#prepare-metadata-for-build-editable
+    """
+    from hatchling.builders.wheel import EDITABLES_MINIMUM_VERSION, WheelBuilder
+
+    builder = WheelBuilder(os.getcwd(), config=CONFIG)
+
+    directory = os.path.join(metadata_directory, f'{builder.artifact_project_id}.dist-info')
+    if not os.path.isdir(directory):
+        os.mkdir(directory)
+
+    extra_dependencies = []
+    if not builder.config.dev_mode_dirs and builder.config.dev_mode_exact:
+        extra_dependencies.append(f'editables~={EDITABLES_MINIMUM_VERSION}')
+
+    with open(os.path.join(directory, 'METADATA'), 'w', encoding='utf-8') as f:
+        f.write(builder.config.core_metadata_constructor(builder.metadata, extra_dependencies=extra_dependencies))
+
+    return os.path.basename(directory)

docs/history.md

@@ -174,6 +174,7 @@ This is the first stable release of Hatch v1, a complete rewrite. Enjoy!
 
 ***Added:***
 
+- Implement a minimal version of `prepare_metadata_for_build_wheel` and `prepare_metadata_for_build_editable` for non-frontend tools that only need to inspect a project's metadata
 - Add `metadata` command to view PEP 621 project metadata
 - Improve error messages for SPDX license errors
 - Retroactively support `License-File` for core metadata starting at version 2.1