fix(test): correctly handle beam_search in generate text

tests/generate/test_generate.py

@@ -279,10 +279,19 @@ def get_inputs(fixture_name, batch_size=None):
 @pytest.mark.parametrize("model_fixture", ALL_MODEL_FIXTURES)
 def test_generate_text(request, model_fixture, sampler_name):
     model = request.getfixturevalue(model_fixture)
-    generator = generate.text(model, getattr(samplers, sampler_name)())
     with enforce_not_implemented(model_fixture, sampler_name):
-        res = generator(**get_inputs(model_fixture), max_tokens=10)
-        assert isinstance(res, str)
+        if sampler_name == "beam_search":
+            num_head = 2
+            generator = generate.text(model, getattr(samplers, sampler_name)(num_head))
+            res = generator(**get_inputs(model_fixture), max_tokens=10)
+            assert isinstance(res, list)
+            assert len(res) == num_head
+            for elt in res:
+                assert isinstance(elt, str)
+        else:
+            generator = generate.text(model, getattr(samplers, sampler_name)())
+            res = generator(**get_inputs(model_fixture), max_tokens=10)
+            assert isinstance(res, str)
 
 
 @pytest.mark.parametrize("pattern", REGEX_PATTERNS)