Remove variable proxying (#181)

close #175

Author: sloria

CHANGELOG.md

@@ -2,6 +2,8 @@
 
 ## 9.0.0 (unreleased)
 
+- _Backwards-incompatible_: Remove variable proxying. Use variable expansion instead (see 8.1.0 release notes below)
+  ([#175](https://github.com/sloria/environs/issues/175)).
 - _Backwards-incompatible_: Drop support for marshmallow 2 and Python 3.5,
   which are both EOL ([#174](https://github.com/sloria/environs/issues/174)).
 

README.md

@@ -18,7 +18,6 @@ It allows you to store configuration separate from your code, as per
 - [Reading .env files](#reading-env-files)
   - [Reading a specific file](#reading-a-specific-file)
 - [Handling prefixes](#handling-prefixes)
-- [Proxied variables](#proxied-variables)
 - [Variable expansion](#variable-expansion)
 - [Validation](#validation)
 - [Deferred validation](#deferred-validation)
@@ -184,17 +183,6 @@ connection_url = env("CONNECTION_URL")  # =>'https://sloria:secret@localhost'
 year = env.int("YEAR")  # =>2020
 ```
 
-## Proxied variables
-
-**Deprecated: use [Variable expansion](#variable-expansion) instead of proxied variables.**
-
-```python
-# export MAILGUN_LOGIN=sloria
-# export SMTP_LOGIN={{MAILGUN_LOGIN}}
-
-smtp_login = env("SMTP_LOGIN")  # =>'sloria'
-```
-
 ## Validation
 
 ```python
@@ -420,7 +408,7 @@ environs will help you
 - validate envvars
 - parse list and dict values
 - parse dates, datetimes, and timedeltas
-- parse proxied variables
+- parse expanded variables
 - serialize your configuration to JSON, YAML, etc.
 
 ### Why another library?

environs/__init__.py

@@ -8,7 +8,6 @@
 import re
 import typing
 import types
-import warnings
 from collections.abc import Mapping
 from urllib.parse import urlparse, ParseResult
 from pathlib import Path
@@ -20,8 +19,6 @@
 __version__ = "8.1.0"
 __all__ = ["EnvError", "Env"]
 
-_PROXIED_PATTERN = re.compile(r"\s*{{\s*(\S*)\s*}}\s*")
-_EXPANDED_VAR_PATTERN = re.compile(r"(?<!\\)\$\{([A-Za-z0-9_]+)(:-[^\}:]*)?\}")
 
 _T = typing.TypeVar("_T")
 _StrType = str
@@ -37,6 +34,9 @@
 ParserMethod = typing.Callable[..., typing.Union[_T, _Missing]]
 
 
+_EXPANDED_VAR_PATTERN = re.compile(r"(?<!\\)\$\{([A-Za-z0-9_]+)(:-[^\}:]*)?\}")
+
+
 class EnvError(ValueError):
     """Raised when an environment variable or if a required environment variable is unset."""
 
@@ -51,10 +51,6 @@ class EnvSealedError(TypeError, EnvError):
     pass
 
 
-class RemovedInEnvirons9Warning(DeprecationWarning):
-    pass
-
-
 class ParserConflictError(ValueError):
     """Raised when adding a custom parser that conflicts with a built-in parser method."""
 
@@ -411,16 +407,6 @@ def _get_from_environ(
         env_key = self._get_key(key, omit_prefix=proxied)
         value = os.environ.get(env_key, default)
         if hasattr(value, "strip"):
-            # TODO: Remove proxying in environs 9
-            proxy_match = _PROXIED_PATTERN.match(value)
-            if proxy_match:  # Proxied variable
-                proxied_key = proxy_match.groups()[0]
-                warnings.warn(
-                    "Proxied variables are deprecated and will be removed in environs 9. "
-                    "Use variable expansion instead: ${{{proxied_key}}}".format(proxied_key=proxied_key),
-                    RemovedInEnvirons9Warning,
-                )
-                return (key, self._get_from_environ(proxied_key, default, proxied=True)[1], proxied_key)
             expand_match = self.expand_vars and _EXPANDED_VAR_PATTERN.match(value)
             if expand_match:  # Full match expand_vars - special case keep default
                 proxied_key = expand_match.groups()[0]

tests/.env

@@ -3,5 +3,4 @@ ignored
 STRING=foo
 BOOL=true
 LIST=wat,wer,wen
-PROXIED={{STRING}}
 EXPANDED=${STRING}

tests/test_environs.py

@@ -201,53 +201,6 @@ def test_invalid_url(self, url, set_env, env):
         assert 'Environment variable "URL" invalid' in excinfo.value.args[0]
 
 
-class TestProxiedVariables:
-    def test_reading_proxied_variable(self, set_env, env):
-        set_env(
-            {
-                "MAILGUN_SMTP_LOGIN": "sloria",
-                "SMTP_LOGIN": "{{MAILGUN_SMTP_LOGIN}}",
-                "SMTP_LOGIN_LPADDED": "{{ MAILGUN_SMTP_LOGIN}}",
-                "SMTP_LOGIN_RPADDED": "{{MAILGUN_SMTP_LOGIN }}",
-            }
-        )
-        assert env("MAILGUN_SMTP_LOGIN") == "sloria"
-        assert env.dump()["MAILGUN_SMTP_LOGIN"] == "sloria"
-        for key in ("SMTP_LOGIN", "SMTP_LOGIN_LPADDED", "SMTP_LOGIN_RPADDED"):
-            with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-                assert env(key) == "sloria"
-            assert env.dump()[key] == "sloria"
-
-    def test_reading_missing_proxied_variable(self, set_env, env):
-        set_env({"SMTP_LOGIN": "{{MAILGUN_SMTP_LOGIN}}"})
-        with pytest.raises(environs.EnvError) as excinfo:
-            with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-                env("SMTP_LOGIN")
-        assert excinfo.value.args[0] == 'Environment variable "MAILGUN_SMTP_LOGIN" not set'
-        with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-            assert env("SMTP_LOGIN", "default") == "default"
-
-    def test_reading_proxied_variable_in_prefix_scope(self, set_env, env):
-        set_env(
-            {
-                "MAILGUN_SMTP_LOGIN": "szabolcs",
-                "SMTP_LOGIN": "{{MAILGUN_SMTP_LOGIN}}",
-                "SMTP_PASSWORD": "secret",
-                "SMTP_NESTED_LOGIN": "{{SMTP_LOGIN}}",
-                "SMTP_NESTED_PASSWORD": "nested-secret",
-            }
-        )
-
-        with env.prefixed("SMTP_"):
-            with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-                assert env.str("LOGIN") == "szabolcs"
-            assert env.str("PASSWORD") == "secret"
-            with env.prefixed("NESTED_"):
-                with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-                    assert env.str("LOGIN") == "szabolcs"
-                assert env.str("PASSWORD") == "nested-secret"
-
-
 class TestEnvFileReading:
     def test_read_env(self, env):
         if "STRING" in os.environ:
@@ -256,8 +209,6 @@ def test_read_env(self, env):
         env.read_env()
         assert env("STRING") == "foo"
         assert env.list("LIST") == ["wat", "wer", "wen"]
-        with pytest.warns(DeprecationWarning, match="Proxied variables are deprecated"):
-            assert env("PROXIED") == "foo"
         assert env("EXPANDED") == "foo"
 
     # Regression test for https://github.com/sloria/environs/issues/96