Add ability to change settings via environment variables

thefuck/conf.py

@@ -0,0 +1,120 @@
+from copy import copy
+from imp import load_source
+import os
+import sys
+from six import text_type
+from . import logs
+
+
+class RulesList(object):
+    """Wrapper a top of list for string rules names."""
+
+    def __init__(self, rules):
+        self.rules = rules
+
+    def __contains__(self, item):
+        return item.name in self.rules
+
+    def __getattr__(self, item):
+        return getattr(self.rules, item)
+
+    def __eq__(self, other):
+        return self.rules == other
+
+
+class _DefaultRules(RulesList):
+    def __add__(self, items):
+        return _DefaultRules(self.rules + items)
+
+    def __contains__(self, item):
+        return item.enabled_by_default or \
+               super(_DefaultRules, self).__contains__(item)
+
+    def __eq__(self, other):
+        if isinstance(other, _DefaultRules):
+            return self.rules == other.rules
+        else:
+            return False
+
+
+DEFAULT = _DefaultRules([])
+
+
+class BaseSettings(object):
+    def __init__(self, conf):
+        self._conf = conf
+
+    def __getattr__(self, item):
+        return self._conf.get(item)
+
+    def update(self, **kwargs):
+        """Returns new settings with new values from `kwargs`."""
+        conf = copy(self._conf)
+        conf.update(kwargs)
+        return BaseSettings(conf)
+
+
+class Settings(BaseSettings):
+    """Settings loaded from defaults/file/env."""
+    defaults = {'rules': DEFAULT,
+                'wait_command': 3,
+                'require_confirmation': False,
+                'no_colors': False}
+
+    env_to_attr = {'THEFUCK_RULES': 'rules',
+                   'THEFUCK_WAIT_COMMAND': 'wait_command',
+                   'THEFUCK_REQUIRE_CONFIRMATION': 'require_confirmation',
+                   'THEFUCK_NO_COLORS': 'no_colors'}
+
+    def __init__(self, user_dir):
+        super(Settings, self).__init__(self._load_conf(user_dir))
+
+    def _load_conf(self, user_dir):
+        conf = copy(self.defaults)
+        try:
+            conf.update(self._load_from_file(user_dir))
+        except:
+            logs.exception("Can't load settings from file",
+                           sys.exc_info(),
+                           BaseSettings(conf))
+        try:
+            conf.update(self._load_from_env())
+        except:
+            logs.exception("Can't load settings from env",
+                           sys.exc_info(),
+                           BaseSettings(conf))
+        if not isinstance(conf['rules'], RulesList):
+            conf['rules'] = RulesList(conf['rules'])
+        return conf
+
+    def _load_from_file(self, user_dir):
+        """Loads settings from file."""
+        settings = load_source('settings',
+                               text_type(user_dir.joinpath('settings.py')))
+        return {key: getattr(settings, key)
+                for key in self.defaults.keys()
+                if hasattr(settings, key)}
+
+    def _load_from_env(self):
+        """Loads settings from env."""
+        return {attr: self._val_from_env(env, attr)
+                for env, attr in self.env_to_attr.items()
+                if env in os.environ}
+
+    def _val_from_env(self, env, attr):
+        """Transforms env-strings to python."""
+        val = os.environ[env]
+        if attr == 'rules':
+            val = self._rules_from_env(val)
+        elif attr == 'wait_command':
+            val = int(val)
+        elif attr in ('require_confirmation', 'no_colors'):
+            val = val.lower() == 'true'
+        return val
+
+    def _rules_from_env(self, val):
+        """Transforms rules list from env-string to python."""
+        val = val.split(':')
+        if 'DEFAULT' in val:
+            val = DEFAULT + [rule for rule in val if rule != 'DEFAULT']
+        return val