test: add tests for new UI components and update language format

Add tests for clear button, character count, output placeholder,
filterable dropdown, locale codes, and no-title check. Update
existing tests to use "French (fr)" display format.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

tests/test_app.py

@@ -95,9 +95,9 @@ def test_demo_has_dropdown(demo):
 
 
 def test_dropdown_default_is_french(demo):
-    """Default dropdown value should be French."""
+    """Default dropdown value should be French (fr)."""
     dropdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Dropdown"]
-    assert dropdowns[0].value == "French"
+    assert dropdowns[0].value == "French (fr)"
 
 
 def test_demo_has_two_textboxes(demo):
@@ -119,12 +119,55 @@ def test_demo_has_translate_button(demo):
     assert any(b.value == "Translate" for b in buttons), "Expected a 'Translate' button"
 
 
-def test_translate_button_wires_only_text_and_language(demo):
-    """Translate button should only wire input text and target language (no sliders)."""
-    assert len(demo.fns) == 1, f"Expected 1 event handler, found {len(demo.fns)}"
-    fn = list(demo.fns.values())[0]
-    input_types = [type(i).__name__ for i in fn.inputs]
-    assert input_types == ["Textbox", "Dropdown"], f"Expected [Textbox, Dropdown], got {input_types}"
+def test_demo_has_clear_button(demo):
+    """UI should have a Clear button."""
+    buttons = [b for b in demo.blocks.values() if type(b).__name__ == "Button"]
+    assert any(b.value == "Clear" for b in buttons), "Expected a 'Clear' 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"]]
+    assert len(translate_fns) == 2, f"Expected 2 translate handlers (click + submit), found {len(translate_fns)}"
+
+
+def test_char_count_handler_exists(demo):
+    """Character count handler should wire input text to markdown output."""
+    char_fns = [
+        fn
+        for fn in demo.fns.values()
+        if [type(i).__name__ for i in fn.inputs] == ["Textbox"]
+        and [type(o).__name__ for o in fn.outputs] == ["Markdown"]
+    ]
+    assert len(char_fns) == 1, f"Expected 1 char count handler, found {len(char_fns)}"
+
+
+def test_output_placeholder(demo):
+    """Output textbox should have 'Translation' as placeholder."""
+    textboxes = [b for b in demo.blocks.values() if type(b).__name__ == "Textbox"]
+    output = [t for t in textboxes if t.interactive is False]
+    assert output[0].placeholder == "Translation"
+
+
+def test_no_title(demo):
+    """UI should not have an H1 title."""
+    markdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Markdown"]
+    for md in markdowns:
+        assert not md.value.startswith("# "), f"Found unexpected title: {md.value}"
+
+
+def test_dropdown_is_filterable(demo):
+    """Dropdown should be filterable/searchable."""
+    dropdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Dropdown"]
+    assert dropdowns[0].filterable is True
+
+
+def test_dropdown_choices_include_locale_codes(demo):
+    """Dropdown choices should include locale codes like 'French (fr)'."""
+    dropdowns = [b for b in demo.blocks.values() if type(b).__name__ == "Dropdown"]
+    # Gradio stores choices as (label, value) tuples
+    labels = [c[0] if isinstance(c, tuple) else c for c in dropdowns[0].choices]
+    assert all("(" in label and ")" in label for label in labels), f"Expected locale codes in choices: {labels}"
 
 
 # --- Slow tests (require CUDA + model download) ---
@@ -174,7 +217,7 @@ def test_translate_unsupported_language(loaded_app):
 @pytest.mark.slow
 @pytest.mark.skipif(not gpu_available, reason="Requires CUDA")
 def test_translate_returns_string(loaded_app):
-    result = loaded_app.translate("Hello", "French")
+    result = loaded_app.translate("Hello", "French (fr)")
     assert isinstance(result, str)
     assert len(result) > 0
 
@@ -183,7 +226,7 @@ def test_translate_returns_string(loaded_app):
 @pytest.mark.skipif(not gpu_available, reason="Requires CUDA")
 def test_translate_with_beam_search(loaded_app):
     """Translation with beam search (num_beams=4) should return a string."""
-    result = loaded_app.translate("Hello", "French", num_beams=4)
+    result = loaded_app.translate("Hello", "French (fr)", num_beams=4)
     assert isinstance(result, str)
     assert len(result) > 0
 
@@ -192,7 +235,7 @@ def test_translate_with_beam_search(loaded_app):
 @pytest.mark.skipif(not gpu_available, reason="Requires CUDA")
 def test_translate_with_custom_temperature(loaded_app):
     """Translation with custom temperature should return a string."""
-    result = loaded_app.translate("Hello", "French", temperature=0.5)
+    result = loaded_app.translate("Hello", "French (fr)", temperature=0.5)
     assert isinstance(result, str)
     assert len(result) > 0
 
@@ -201,7 +244,7 @@ def test_translate_with_custom_temperature(loaded_app):
 @pytest.mark.skipif(not gpu_available, reason="Requires CUDA")
 def test_translate_with_custom_max_tokens(loaded_app):
     """Translation with low max_new_tokens should return a short string."""
-    result = loaded_app.translate("Hello", "French", max_new_tokens=10)
+    result = loaded_app.translate("Hello", "French (fr)", max_new_tokens=10)
     assert isinstance(result, str)
 
 
@@ -209,7 +252,7 @@ def test_translate_with_custom_max_tokens(loaded_app):
 @pytest.mark.skipif(not gpu_available, reason="Requires CUDA")
 def test_translate_empty_string(loaded_app):
     """Translating an empty string should not crash."""
-    result = loaded_app.translate("", "French")
+    result = loaded_app.translate("", "French (fr)")
     assert isinstance(result, str)
 
 
@@ -218,6 +261,6 @@ def test_translate_empty_string(loaded_app):
 def test_translate_beam_search_ignores_temperature(loaded_app):
     """When beam search is active with non-default temperature, gr.Info should be called."""
     with patch("app.gr.Info") as mock_info:
-        result = loaded_app.translate("Hello", "French", num_beams=4, temperature=0.5)
+        result = loaded_app.translate("Hello", "French (fr)", num_beams=4, temperature=0.5)
         mock_info.assert_called_once()
     assert isinstance(result, str)