Add config.default_from_env_as_list

Author: soxofaan

openeo_driver/_version.py

@@ -1 +1 @@
-__version__ = "0.67.1a1"
+__version__ = "0.67.2a1"

openeo_driver/config/__init__.py

@@ -1,3 +1,3 @@
 from openeo_driver.config.config import OpenEoBackendConfig, ConfigException
 from openeo_driver.config.load import get_backend_config
-from openeo_driver.config.env import from_env, from_env_as_list
+from openeo_driver.config.env import from_env, from_env_as_list, default_from_env_as_list

openeo_driver/config/env.py

@@ -39,7 +39,7 @@ def get():
 
 
 def to_list(value: str, *, strip: bool = True, separator: str = ",") -> List[str]:
-    """Split a string to a list, properly handling leading/trailing whitespace and empty items."""
+    """Split a string to a list, properly stripping leading/trailing whitespace and skipping empty items."""
     result = value.split(separator)
     if strip:
         result = [s.strip() for s in result]
@@ -52,7 +52,7 @@ def from_env_as_list(
 ) -> Callable[[], List[str]]:
     """
     Attrs default factory to get a list from an env var
-    (properly handling leading/trailing whitespace and empty items).
+    (automatically splitting with separator, stripping leading/trailing whitespace and skipping empty items):
 
     Usage example:
 
@@ -84,3 +84,31 @@ def get():
         return value
 
     return get
+
+
+def default_from_env_as_list(
+    var: str, *, default: Union[str, List[str]] = "", strip: bool = True, separator: str = ","
+):
+    """
+    Build an attrs default value that, by default, takes the value of given environment variable
+    and splits it into a list (automatically stripping leading/trailing whitespace and skipping empty items):
+
+        >>> @attrs.define
+        ... class Config:
+        ...    colors: List[str] = default_from_env_as_list("COLORS")
+
+        >>> Config().colors
+        []
+        >>> os.environ["COLORS"] = "blue,black"
+        >>> Config().color
+        ["blue", "black"]
+        >>> Config(colors=["green", "white"]).colors
+        ["green", "white"]
+
+    :param var: env var name
+    :param default: fallback value to parse if env var is not set
+    :param strip: whether to strip surrounding whitespace
+    :param separator: item separator
+    :return: default value to use for attributes in a `@attrs.define` class
+    """
+    return attrs.field(factory=from_env_as_list(var=var, default=default, strip=strip, separator=separator))

tests/test_config.py

@@ -9,7 +9,14 @@
 import pytest
 
 import openeo_driver.config.load
-from openeo_driver.config import ConfigException, OpenEoBackendConfig, get_backend_config, from_env, from_env_as_list
+from openeo_driver.config import (
+    ConfigException,
+    OpenEoBackendConfig,
+    get_backend_config,
+    from_env,
+    from_env_as_list,
+    default_from_env_as_list,
+)
 from openeo_driver.config.load import load_from_py_file
 import openeo_driver.config.env
 from .conftest import enhanced_logging
@@ -272,3 +279,34 @@ class Config:
             colors: List[str] = attrs.Factory(from_env_as_list("COLORS", default=["red", "blue"]))
 
         assert Config().colors == ["red", "blue"]
+
+    def test_default_from_env_as_list_basic(self, monkeypatch):
+        @attrs.frozen(kw_only=True)
+        class Config:
+            colors: List[str] = default_from_env_as_list("COLORS", default="red,blue")
+
+        conf = Config()
+        assert conf.colors == ["red", "blue"]
+
+        conf = Config(colors=["green"])
+        assert conf.colors == ["green"]
+
+        monkeypatch.setenv("COLORS", "purple,yellow")
+
+        conf = Config()
+        assert conf.colors == ["purple", "yellow"]
+
+        conf = Config(colors=["green"])
+        assert conf.colors == ["green"]
+
+    def test_default_from_env_as_list_empy(self, monkeypatch):
+        @attrs.frozen(kw_only=True)
+        class Config:
+            colors: List[str] = default_from_env_as_list("COLORS")
+
+        assert Config().colors == []
+
+        monkeypatch.setenv("COLORS", "")
+        assert Config().colors == []
+
+        assert Config(colors=[]).colors == []