Refactor meta.yaml lint logic

conda_smithy/cli.py

@@ -4,7 +4,6 @@
 import sys
 import time
 import argparse
-import io
 import tempfile
 
 from textwrap import dedent

conda_smithy/config_file_helpers.py

@@ -0,0 +1,86 @@
+from pathlib import Path
+from typing import Optional
+
+try:
+    from enum import StrEnum
+except ImportError:
+    from backports.strenum import StrEnum
+
+from conda_smithy.utils import get_yaml
+
+
+class MultipleConfigFilesError(ValueError):
+    """
+    Raised when multiple configuration files are found in different locations and only one is allowed.
+    """
+
+    pass
+
+
+class ConfigFileMustBeDictError(ValueError):
+    """
+    Raised when a configuration file does not represent a dictionary.
+    """
+
+    pass
+
+
+class ConfigFileName(StrEnum):
+    CONDA_FORGE_YML = "conda-forge.yml"
+    CONDA_BUILD_CONFIG = "conda_build_config.yaml"
+
+
+def read_local_config_file(
+    recipe_dir: Path, filename: ConfigFileName, enforce_one: bool = True
+) -> dict:
+    """
+    Read a local YAML configuration file from the recipe directory.
+    It is assumed that the local configuration file has a dictionary-like structure.
+    Multiple relative paths are checked for the file in a specific order.
+
+    :param recipe_dir: the recipe directory of a feedstock
+    :param filename: the name of the configuration file
+    :param enforce_one: if True, only one config file with the given name is allowed when looking for it in different
+    locations. If False, the contents of the first file found is returned.
+
+    :raises FileNotFoundError if the file does not exist in all possible locations
+    :raises ConfigFileMustBeDictError if the file does not represent a dictionary
+    (takes precedence over MultipleConfigFilesError)
+    :raises MultipleConfigFilesError if multiple files are found and only one is allowed
+    """
+
+    file_candidates = [
+        recipe_dir / filename,
+        recipe_dir / ".." / filename,
+        recipe_dir / ".." / ".." / filename,
+    ]
+
+    file_contents: Optional[dict] = None
+
+    for file in file_candidates:
+        if file_contents is not None and file.exists():
+            # we know that enforce_one is True since otherwise we would have returned already
+            raise MultipleConfigFilesError(
+                f"Multiple configuration files '{filename}' found in different locations relative to {recipe_dir}."
+            )
+
+        try:
+            file_contents = get_yaml().load(file)
+        except FileNotFoundError:
+            continue
+
+        if not isinstance(file_contents, dict):
+            raise ConfigFileMustBeDictError(
+                f"The YAML configuration file '{file}' does not represent a dictionary."
+            )
+
+        if not enforce_one:
+            # early return
+            return file_contents
+
+    if file_contents is not None:
+        return file_contents
+
+    raise FileNotFoundError(
+        f"No {filename} file found in any of the following locations: {', '.join(map(str, file_candidates))}"
+    )

conda_smithy/configure_feedstock.py

@@ -2698,7 +2698,7 @@ def main(
     import argparse
 
     parser = argparse.ArgumentParser(
-        description=("Configure a feedstock given " "a conda-forge.yml file.")
+        description="Configure a feedstock given a conda-forge.yml file."
     )
     parser.add_argument(
         "forge_file_directory",