feat: implement middle_name_as_last fold (#133)

Author: derek73

nameparser/parser.py

@@ -753,6 +753,15 @@ def handle_patronymic_name_order(self) -> None:
                 self.first_list,
             )
 
+    def handle_middle_name_as_last(self) -> None:
+        """
+        When middle_name_as_last is enabled, fold middle_list into last_list
+        (prepended, preserving order) and clear middle_list. No-op when
+        middle_list is already empty.
+        """
+        self.last_list = self.middle_list + self.last_list
+        self.middle_list = []
+
     def post_process(self) -> None:
         """
         This happens at the end of the :py:func:`parse_full_name` after
@@ -762,6 +771,8 @@ def post_process(self) -> None:
         self.handle_firstnames()
         if self.C.patronymic_name_order:
             self.handle_patronymic_name_order()
+        if self.C.middle_name_as_last:
+            self.handle_middle_name_as_last()
         self.handle_capitalization()
 
     def fix_phd(self) -> None:

tests/test_middle_name_as_last.py

@@ -1,3 +1,4 @@
+from nameparser import HumanName
 from nameparser.config import Constants
 from tests.base import HumanNameTestBase
 
@@ -17,3 +18,64 @@ def test_does_not_affect_other_instance(self) -> None:
         C2 = Constants()
         assert C1.middle_name_as_last is True
         assert C2.middle_name_as_last is False
+
+
+class MiddleNameAsLastFoldTests(HumanNameTestBase):
+
+    def setup_method(self) -> None:
+        self.C = Constants(middle_name_as_last=True)
+
+    def hn(self, name: str) -> HumanName:
+        return HumanName(name, constants=self.C)
+
+    def test_fold_no_comma(self) -> None:
+        n = self.hn("Mohamad Ahmad Ali Hassan")
+        self.m(n.first, "Mohamad", n)
+        self.m(n.middle, "", n)
+        self.m(n.last, "Ahmad Ali Hassan", n)
+
+    def test_fold_comma_converges(self) -> None:
+        no_comma = self.hn("Mohamad Ahmad Ali Hassan")
+        comma = self.hn("Hassan, Mohamad Ahmad Ali")
+        self.m(comma.first, no_comma.first, comma)
+        self.m(comma.last, no_comma.last, comma)
+
+    def test_title_and_suffix_preserved(self) -> None:
+        n = self.hn("Dr. Mohamad Ahmad Hassan Jr")
+        self.m(n.title, "Dr.", n)
+        self.m(n.last, "Ahmad Hassan", n)
+        self.m(n.suffix, "Jr", n)
+
+    def test_no_middle_is_noop(self) -> None:
+        n = self.hn("John Doe")
+        self.m(n.first, "John", n)
+        self.m(n.middle, "", n)
+        self.m(n.last, "Doe", n)
+
+    def test_single_token_is_noop(self) -> None:
+        n = self.hn("Cher")
+        self.m(n.first, "Cher", n)
+        self.m(n.last, "", n)
+
+    def test_given_names_and_surnames_track_fold(self) -> None:
+        n = self.hn("Mohamad Ahmad Ali Hassan")
+        self.m(n.given_names, n.first, n)
+        self.m(n.surnames, n.last, n)
+
+    def test_last_prefixes_still_split_after_fold(self) -> None:
+        # Unfolded this is first="Miguel", middle="da Silva do Amaral",
+        # last="de Souza" (last_prefixes="de"). Folded, last_list becomes
+        # ["da","Silva","do","Amaral","de","Souza"]; _split_last() strips
+        # leading contiguous prefix words from the start, so only the
+        # leading "da" is stripped ("Silva" is not a prefix, so scanning
+        # stops there) — last_prefixes="da", not "de".
+        n = self.hn("Miguel da Silva do Amaral de Souza")
+        self.m(n.last_prefixes, "da", n)
+
+
+class MiddleNameAsLastFlagOffTests(HumanNameTestBase):
+
+    def test_default_constants_unaffected(self) -> None:
+        n = HumanName("Mohamad Ahmad Ali Hassan")
+        self.m(n.middle, "Ahmad Ali", n)
+        self.m(n.last, "Hassan", n)