Add unit test for new functions

tests/unit/single_table/test_copulas.py

@@ -245,6 +245,66 @@ def test__fit_mocked_instance(self):
         instance._initialize_model.assert_called_once_with(numerical_distributions)
         instance._fit_model.assert_called_once_with(processed_data)
 
+    def test__learn_num_rows(self):
+        """Test that the `_learn_num_rows` method returns the correct number of rows."""
+        # Setup
+        metadata = Metadata()
+        instance = GaussianCopulaSynthesizer(metadata)
+        processed_data = pd.DataFrame({'a': range(5), 'b': range(5)})
+
+        # Run
+        result = instance._learn_num_rows(processed_data)
+
+        # Assert
+        assert result == 5
+
+    def test__get_numerical_distributions_with_existing_columns(self):
+        """Test that `_get_numerical_distributions` returns correct distributions."""
+        # Setup
+        metadata = Metadata()
+        instance = GaussianCopulaSynthesizer(metadata)
+        instance._numerical_distributions = {'a': 'dist_a', 'b': 'dist_b'}
+        instance._default_distribution = 'default_dist'
+
+        processed_data = Mock()
+        processed_data.columns = ['a', 'b', 'c']
+
+        # Run
+        result = instance._get_numerical_distributions(processed_data)
+
+        # Assert
+        expected_result = {'a': 'dist_a', 'b': 'dist_b', 'c': 'default_dist'}
+        assert result == expected_result
+
+    @patch('sdv.single_table.copulas.multivariate.GaussianMultivariate')
+    def test__initialize_model(self, mock_gaussian_multivariate):
+        """Test that `_initialize_model` calls the GaussianMultivariate with correct parameters."""
+        # Setup
+        metadata = Metadata()
+        instance = GaussianCopulaSynthesizer(metadata)
+        numerical_distributions = {'a': 'dist_a', 'b': 'dist_b'}
+
+        # Run
+        model = instance._initialize_model(numerical_distributions)
+
+        # Assert
+        mock_gaussian_multivariate.assert_called_once_with(distribution=numerical_distributions)
+        assert model == mock_gaussian_multivariate.return_value
+
+    def test__fit_model(self):
+        """Test that `_fit_model` fits the model correctly."""
+        # Setup
+        metadata = Metadata()
+        instance = GaussianCopulaSynthesizer(metadata)
+        instance._model = Mock()
+        processed_data = Mock()
+
+        # Run
+        instance._fit_model(processed_data)
+
+        # Assert
+        instance._model.fit.assert_called_once_with(processed_data)
+
     def test__get_nearest_correlation_matrix_valid(self):
         """Test ``_get_nearest_correlation_matrix`` with a psd input.