Merge pull request #333 from mehdy/develop

Handle escaped dollar sign in values

CHANGELOG.rst

@@ -24,6 +24,8 @@ Fixed
 +++++
 - Keep newline/tab escapes in quoted strings
   `#296 <https://github.com/joke2k/django-environ/pull/296>`_.
+- Handle escaped dolloar sign in values
+  `#271 <https://github.com/joke2k/django-environ/issues/271>`_.
 
 
 `v0.7.0`_ - 11-September-2021

docs/tips.rst

@@ -195,6 +195,23 @@ Values that being with a ``$`` may be interpolated. Pass ``interpolate=True`` to
    FOO
 
 
+Escape Proxy
+============
+
+If you're having trouble with values starting with dollar sign ($) without the intention of proxying the value to
+another, You should enbale the ``escape_proxy`` and prepend a backslash to it.
+
+.. code-block:: python
+
+    import environ
+
+    env = environ.Env()
+    env.escape_proxy = True
+
+    # ESCAPED_VAR=\$baz
+    env.str('ESCAPED_VAR')  # $baz
+
+
 Reading env files
 =================
 

environ/environ.py

@@ -160,6 +160,7 @@ class Env:
 
     def __init__(self, **scheme):
         self.smart_cast = True
+        self.escape_proxy = False
         self.scheme = scheme
 
     def __call__(self, var, cast=None, default=NOTSET, parse_default=False):
@@ -365,10 +366,14 @@ def get_value(self, var, cast=None, default=NOTSET, parse_default=False):
 
         # Resolve any proxied values
         prefix = b'$' if isinstance(value, bytes) else '$'
+        escape = rb'\$' if isinstance(value, bytes) else r'\$'
         if hasattr(value, 'startswith') and value.startswith(prefix):
             value = value.lstrip(prefix)
             value = self.get_value(value, cast=cast, default=default)
 
+        if self.escape_proxy and hasattr(value, 'replace'):
+            value = value.replace(escape, prefix)
+
         # Smart casting
         if self.smart_cast:
             if cast is None and default is not None and \

tests/fixtures.py

@@ -53,6 +53,7 @@ def generate_data(cls):
                     BOOL_FALSE_STRING_LIKE_BOOL='False',
                     BOOL_FALSE_BOOL=False,
                     PROXIED_VAR='$STR_VAR',
+                    ESCAPED_VAR=r'\$baz',
                     INT_LIST='42,33',
                     INT_TUPLE='(42,33)',
                     STR_LIST_WITH_SPACES=' foo,  bar',

tests/test_env.py

@@ -127,6 +127,14 @@ def test_bool_true(self, value, variable):
     def test_proxied_value(self):
         assert self.env('PROXIED_VAR') == 'bar'
 
+    def test_escaped_dollar_sign(self):
+        self.env.escape_proxy = True
+        assert self.env('ESCAPED_VAR') == '$baz'
+
+    def test_escaped_dollar_sign_disabled(self):
+        self.env.escape_proxy = False
+        assert self.env('ESCAPED_VAR') == r'\$baz'
+
     def test_int_list(self):
         assert_type_and_value(list, [42, 33], self.env('INT_LIST', cast=[int]))
         assert_type_and_value(list, [42, 33], self.env.list('INT_LIST', int))

tests/test_env.txt

@@ -28,6 +28,7 @@ FLOAT_STRANGE_VAR1=123,420,333.3
 FLOAT_STRANGE_VAR2=123.420.333,3
 FLOAT_NEGATIVE_VAR=-1.0
 PROXIED_VAR=$STR_VAR
+ESCAPED_VAR=\$baz
 EMPTY_LIST=
 EMPTY_INT_VAR=
 INT_VAR=42