Fix zh Hant/Hans (#91390)

* Fix zh Hant/Hans

* Fix comments

homeassistant/util/language.py

@@ -16,7 +16,11 @@ def preferred_regions(
     country: str | None = None,
     code: str | None = None,
 ) -> Iterable[str | None]:
-    """Yield preferred regions for a language based on country/code hints."""
+    """Yield an ordered list of regions for a language based on country/code hints.
+
+    Regions should be checked for support in the returned order if no other
+    information is available.
+    """
     if country is not None:
         yield country.upper()
 
@@ -27,10 +31,8 @@ def preferred_regions(
     elif language == "zh":
         if code == "Hant":
             yield "HK"
-        elif code == "Hans":
             yield "TW"
         else:
-            # Prefer China if no matching code
             yield "CN"
 
     # fr -> fr-FR

tests/util/test_language.py

@@ -95,31 +95,40 @@ def test_language_as_region() -> None:
 
 
 def test_zh_hant() -> None:
-    """Test that the zh-Hant defaults to HK."""
+    """Test that the zh-Hant matches HK or TW first."""
     assert language.matches(
         "zh-Hant",
         ["en-US", "en-GB", "zh-CN", "zh-HK", "zh-TW"],
     ) == [
         "zh-HK",
-        "zh-CN",
         "zh-TW",
+        "zh-CN",
+    ]
+
+    assert language.matches(
+        "zh-Hant",
+        ["en-US", "en-GB", "zh-CN", "zh-TW", "zh-HK"],
+    ) == [
+        "zh-TW",
+        "zh-HK",
+        "zh-CN",
     ]
 
 
 def test_zh_hans() -> None:
-    """Test that the zh-Hans defaults to TW."""
+    """Test that the zh-Hans matches CN first."""
     assert language.matches(
         "zh-Hans",
         ["en-US", "en-GB", "zh-CN", "zh-HK", "zh-TW"],
     ) == [
-        "zh-TW",
         "zh-CN",
         "zh-HK",
+        "zh-TW",
     ]
 
 
 def test_zh_no_code() -> None:
-    """Test that the zh defaults to CN."""
+    """Test that the zh defaults to CN first."""
     assert language.matches(
         "zh",
         ["en-US", "en-GB", "zh-CN", "zh-HK", "zh-TW"],