Address code review feedback: use generator expressions and improve test assertions

Co-authored-by: pierotofy <1951843+pierotofy@users.noreply.github.com>

libretranslate/language.py

@@ -48,7 +48,7 @@ def load_lang_codes():
     return tuple(l.code for l in languages)
 
 def get_language_with_fallback(lang_code, languages):
-    lang = next(iter([l for l in languages if l.code == lang_code]), None)
+    lang = next((l for l in languages if l.code == lang_code), None)
     if lang is not None:
         return lang
     
@@ -59,7 +59,7 @@ def get_language_with_fallback(lang_code, languages):
     
     fallbacks = language_variants.get(lang_code, [])
     for fallback_code in fallbacks:
-        fallback_lang = next(iter([l for l in languages if l.code == fallback_code]), None)
+        fallback_lang = next((l for l in languages if l.code == fallback_code), None)
         if fallback_lang is not None:
             return fallback_lang
     

libretranslate/tests/test_api/test_language_variant_fallback.py

@@ -1,4 +1,5 @@
 import sys
+import json
 import pytest
 from libretranslate.app import create_app
 from libretranslate.main import get_args
@@ -36,7 +37,10 @@ def test_portuguese_fallback_pb_to_pt(client_with_pt):
         "format": "text"
     })
     
+    response_json = json.loads(response.data)
     assert response.status_code == 200
+    assert "translatedText" in response_json
+    assert len(response_json["translatedText"]) > 0
 
 
 def test_portuguese_fallback_pt_to_pb(client_with_pb):
@@ -47,4 +51,7 @@ def test_portuguese_fallback_pt_to_pb(client_with_pb):
         "format": "text"
     })
     
+    response_json = json.loads(response.data)
     assert response.status_code == 200
+    assert "translatedText" in response_json
+    assert len(response_json["translatedText"]) > 0