Formalise constraint on _NormalizeString's inputs

Now that all strings given as inputs to _NormalizeString have been
verified (or corrected) to be correctly delimited with double quotes,
there's no reason to continue doing an internal strip anymore. Moreover,
we can express this internal constraint with an assertion to avoid
issues in the future.

Signed-off-by: Rodrigo Tobar <rtobar@icrar.org>

babel/messages/pofile.py

@@ -144,7 +144,8 @@ def __init__(self, *args: str) -> None:
             self.append(arg)
 
     def append(self, s: str) -> None:
-        self._strs.append(s.strip())
+        assert s[0] == '"' and s[-1] == '"'
+        self._strs.append(s)
 
     def denormalize(self) -> str:
         return ''.join(map(unescape, self._strs))

tests/messages/test_normalized_string.py

@@ -4,19 +4,14 @@
 
 
 def test_normalized_string():
-    ab1 = _NormalizedString('"a"', '"b" ')
-    ab2 = _NormalizedString('"a"', ' "b"')
-    ac1 = _NormalizedString('"a"', '"c"')
-    ac2 = _NormalizedString('  "a"', '"c"  ')
+    ab = _NormalizedString('"a"', '"b"')
+    ac = _NormalizedString('"a"', '"c"')
     z = _NormalizedString()
-    assert ab1 == ab2 and ac1 == ac2  # __eq__
-    assert ab1 < ac1  # __lt__
-    assert ac1 > ab2  # __gt__
-    assert ac1 >= ac2  # __ge__
-    assert ab1 <= ab2  # __le__
-    assert ab1 != ac1  # __ne__
+    assert ab < ac  # __lt__
+    assert ac > ab  # __gt__
+    assert ab != ac  # __ne__
     assert not z  # __nonzero__ / __bool__
-    assert sorted([ab1, ab2, ac1]) == [ab1, ab2, ac1] # sorted() is stable
+    assert sorted([ac, ab, z]) == [z, ab, ac] # sorted() is stable
 
 
 @pytest.mark.parametrize(
@@ -38,10 +33,10 @@ def test_denormalized_simple_normalized_string(original, denormalized):
     "originals, denormalized",
     (
         (('"a"', '"b"'), "ab"),
-        (('"a" ', '"b"'), "ab"),
+        (('"a"', '"b"'), "ab"),
         (('"ab"', '""'), "ab"),
         (('"ab"', '"c"'), "abc"),
-        (('"a"', '     "bc"'), "abc"),
+        (('"a"', '"bc"'), "abc"),
     ),
 )
 def test_denormalized_multi_normalized_string(originals, denormalized):