added test for default case of dtype

tests/integration/test_pandas_em.py

@@ -136,10 +136,18 @@ def test_pandas_tfidf(dtype):
         np.testing.assert_allclose(actual_value, exp_value, rtol=0, atol=0.001)
 
 
+def test_pandas_tfidf_default_dtype():
+    pandas_t = PandasNormalizedTfidfVectorizer()
+    unique_names = [str(uuid.uuid4()) for i in range(100)]
+    gt_names = pd.Series(unique_names)
+    pandas_t.fit(gt_names)
+    assert pandas_t.idf_.dtype == np.float32
+
+
 @pytest.mark.parametrize(
     ("dtype", "data_size"), [(np.float32, 100), (np.float64, 100), (np.float32, 1000000), (np.float64, 1000000)]
 )
-def test_pandas_tfidf_dtype(dtype, data_size):
+def test_pandas_tfidf_dtype_for_different_input_sizes(dtype, data_size):
     pandas_t = PandasNormalizedTfidfVectorizer(dtype=dtype)
     unique_names = [str(uuid.uuid4()) for i in range(data_size)]
     gt_names = pd.Series(unique_names)