Strip tokens in ListOf (#241)

src/everett/manager.py

@@ -540,13 +540,19 @@ def get_key_from_envs(envs: Iterable[Any], key: str) -> Union[str, NoValue]:
 class ListOf:
     """Parse a comma-separated list of things.
 
+    After delimiting items, this strips the whitespace at the beginning and end
+    of each string. Then it passes each string into the parser to get the final
+    value.
+
     >>> from everett.manager import ListOf
     >>> ListOf(str)('')
     []
     >>> ListOf(str)('a,b,c,d')
     ['a', 'b', 'c', 'd']
     >>> ListOf(int)('1,2,3,4')
     [1, 2, 3, 4]
+    >>> ListOf(str)('1, 2  ,3,4')
+    ['1', '2', '3', '4']
 
     Note: This doesn't handle quotes or backslashes or any complicated string
     parsing.
@@ -565,7 +571,7 @@ def __init__(self, parser: Callable, delimiter: str = ","):
     def __call__(self, value: str) -> List[Any]:
         parser = get_parser(self.sub_parser)
         if value:
-            return [parser(token) for token in value.split(self.delimiter)]
+            return [parser(token.strip()) for token in value.split(self.delimiter)]
         else:
             return []
 

tests/test_manager.py

@@ -274,6 +274,7 @@ def test_ListOf():
     assert ListOf(str)("foo") == ["foo"]
     assert ListOf(bool)("t,f") == [True, False]
     assert ListOf(int)("1,2,3") == [1, 2, 3]
+    assert ListOf(str)("1  , 2, 3") == ["1", "2", "3"]
     assert ListOf(int, delimiter=":")("1:2") == [1, 2]