Add support for space as separator of multiple email addresses

Also fixes edge cases where string ended with a separator followed by 
whitespace

dmutils/__init__.py

@@ -2,4 +2,4 @@
 from .flask_init import init_app, init_manager
 
 
-__version__ = '43.3.0'
+__version__ = '43.4.0'

dmutils/email/helpers.py

@@ -7,7 +7,9 @@
 
 # List of characters that could be used to separate email addresses,
 # in decreasing precedence order.
-EMAIL_ADDRESS_SEPARATORS = [";", ",", "/"]
+# Space (" ") should almost always be at the end of this list, otherwise
+# it can cause weird issues when there are separators surrounded by space.
+EMAIL_ADDRESS_SEPARATORS = [";", ",", "/", " "]
 
 # Largely copied from https://github.com/alphagov/notifications-utils/blob/\
 #   67889886ec1476136d12e7f32787a7dbd0574cc2/notifications_utils/recipients.py
@@ -101,6 +103,7 @@ def get_email_addresses(string, separators=EMAIL_ADDRESS_SEPARATORS):
             addresses = string.split(sep)
             break  # earlier separators take precedence
 
-    addresses = [s.strip() for s in addresses if s]
+    addresses = (s.strip() for s in addresses)
+    addresses = [s for s in addresses if s]  # remove empty strings that can be left in by the algorithm
 
     return addresses

tests/email/test_helpers.py

@@ -22,8 +22,12 @@
             ["bob@blob"]),
         ("bob@blob.com;bob.blob@job..com",
             ["bob@blob.com", "bob.blob@job..com"]),
+        ("mary.shelley@example.email; ada.lovelace@email.example; ",
+            ["mary.shelley@example.email", "ada.lovelace@email.example"]),
+        ("joan.d'arc@example.email dorothy.vaughn@email.example ",
+            ["joan.d'arc@example.email", "dorothy.vaughn@email.example"]),
         ("Please send emails to bob@blob.com",
-            ["Please send emails to bob@blob.com"]),
+            ["Please", "send", "emails", "to", "bob@blob.com"]),
     )
 )
 def test_get_email_addresses_returns_list_of_valid_email_addresses(multiple_email_addresses, expected):