feat: add loading feedback on Translate button

Wraps translate() in a generator that disables the button and shows "Translating..." on first yield, then restores the button and delivers the result on second yield. Also fixes a pre-existing extra blank line in tests/test_app.py flagged by ruff format.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app.py

@@ -4,6 +4,7 @@ Translates English text to 22 production-ready languages from the MADLAD-400 pap
 """
 
 import warnings
+from collections.abc import Generator
 from functools import lru_cache
 
 import gradio as gr
@@ -89,6 +90,15 @@ def _update_char_count(text: str) -> str:
     return f"{len(text)} / 2,000"
 
 
+def _translate_with_loading(
+    text: str,
+    target_language_name: str,
+) -> Generator[tuple, None, None]:
+    yield gr.update(value="Translating...", interactive=False), gr.update()
+    result = translate(text, target_language_name)
+    yield gr.update(value="Translate", interactive=True), result
+
+
 def _build_demo() -> gr.Blocks:
     _, language_names = _build_language_mappings()
 
@@ -127,9 +137,9 @@ def _build_demo() -> gr.Blocks:
         translate_btn = gr.Button("Translate", variant="primary")
 
         translate_btn.click(
-            fn=translate,
+            fn=_translate_with_loading,
             inputs=[input_text, target_language],
-            outputs=output_text,
+            outputs=[translate_btn, output_text],
         )
         input_text.submit(
             fn=translate,

tests/test_app.py

@@ -127,7 +127,6 @@ def test_demo_has_translate_button(demo):
     assert any(b.value == "Translate" for b in buttons), "Expected a 'Translate' button"
 
 
-
 def test_translate_handlers_wire_text_and_language(demo):
     """Translate click and submit handlers should wire input text and target language."""
     translate_fns = [fn for fn in demo.fns.values() if [type(i).__name__ for i in fn.inputs] == ["Textbox", "Dropdown"]]