Strip down integer ticket numbers (#278)

* Strip down integer ticket numbers

* Update test_builder.py

* Add docstring for new test for the strip feature

src/towncrier/_builder.py

@@ -11,6 +11,15 @@
 from jinja2 import Template
 
 
+def strip_if_integer_string(s):
+    try:
+        i = int(s)
+    except ValueError:
+        return s
+
+    return str(i)
+
+
 # Returns ticket, category and counter or (None, None, None) if the basename
 # could not be parsed or doesn't contain a valid category.
 def parse_newfragment_basename(basename, definitions):
@@ -21,6 +30,7 @@ def parse_newfragment_basename(basename, definitions):
         return invalid
     if len(parts) == 2:
         ticket, category = parts
+        ticket = strip_if_integer_string(ticket)
         return (ticket, category, 0) if category in definitions else invalid
 
     # There are at least 3 parts. Search for a valid category from the second
@@ -35,7 +45,7 @@ def parse_newfragment_basename(basename, definitions):
             # NOTE: This allows news fragment names like fix-1.2.3.feature or
             # something-cool.feature.ext for projects that don't use ticket
             # numbers in news fragment names.
-            ticket = parts[i-1]
+            ticket = strip_if_integer_string(parts[i-1])
             counter = 0
             # Use the following part as the counter if it exists and is a valid
             # digit.

src/towncrier/newsfragments/126.feature

@@ -0,0 +1 @@
+Ticket number from file names will be stripped down to avoid ticket links such as ``#007``.

src/towncrier/test/test_builder.py

@@ -66,3 +66,18 @@ def test_dots_in_ticket_name_and_counter(self):
             parse_newfragment_basename("baz.1.2.feature.3", ["feature"]),
             ("2", "feature", 3),
         )
+
+    def test_strip(self):
+        """Leading spaces and subsequent leading zeros are stripped
+        when parsing newsfragment names into ticket numbers etc.
+        """
+        self.assertEqual(
+            parse_newfragment_basename("  007.feature", ["feature"]),
+            ("7", "feature", 0)
+        )
+
+    def test_strip_with_counter(self):
+        self.assertEqual(
+            parse_newfragment_basename("  007.feature.3", ["feature"]),
+            ("7", "feature", 3)
+        )