refactor(loader): renames _load_from_source to _load_from_local_sourc…

…e removes unreachable code and adds tests for _load_from_local_source (#1514)

* refactor(loader): renames _load_from_source to _load_from_local_source, removes unreachable code and adds tests for _load_from_local_source

* chore: fixing ruff formatting

* Update pandasai/data_loader/loader.py

Co-authored-by: ellipsis-dev[bot] <65095814+ellipsis-dev[bot]@users.noreply.github.com>

---------

Co-authored-by: ellipsis-dev[bot] <65095814+ellipsis-dev[bot]@users.noreply.github.com>

pandasai/data_loader/loader.py

@@ -46,7 +46,7 @@ def load(self, dataset_path: str) -> DataFrame:
                 cache_format = self.schema["destination"]["format"]
                 return self._read_csv_or_parquet(cache_file, cache_format)
 
-            df = self._load_from_source()
+            df = self._load_from_local_source()
             df = self._apply_transformations(df)
 
             # Convert to pandas DataFrame while preserving internal data
@@ -169,18 +169,20 @@ def _read_csv_or_parquet(self, file_path: str, format: str) -> DataFrame:
         else:
             raise ValueError(f"Unsupported file format: {format}")
 
-    def _load_from_source(self) -> pd.DataFrame:
+    def _load_from_local_source(self) -> pd.DataFrame:
         source_type = self.schema["source"]["type"]
-        if source_type in ["csv", "parquet"]:
-            filepath = os.path.join(
-                self._get_abs_dataset_path(),
-                self.schema["source"]["path"],
+
+        if source_type not in LOCAL_SOURCE_TYPES:
+            raise InvalidDataSourceType(
+                f"Unsupported local source type: {source_type}. Supported types are: {LOCAL_SOURCE_TYPES}."
             )
-            return self._read_csv_or_parquet(filepath, source_type)
 
-        query_builder = QueryBuilder(self.schema)
-        query = query_builder.build_query()
-        return self.execute_query(query)
+        filepath = os.path.join(
+            str(self._get_abs_dataset_path()),
+            self.schema["source"]["path"],
+        )
+
+        return self._read_csv_or_parquet(filepath, source_type)
 
     def load_head(self) -> pd.DataFrame:
         query_builder = QueryBuilder(self.schema)

tests/unit_tests/dataframe/test_loader.py

@@ -7,6 +7,7 @@
 
 from pandasai.data_loader.loader import DatasetLoader
 from pandasai.dataframe.base import DataFrame
+from pandasai.exceptions import InvalidDataSourceType
 
 
 class TestDatasetLoader:
@@ -109,8 +110,8 @@ def test_load_from_cache(self, sample_schema):
         ) as mock_read_cache, patch(
             "builtins.open", mock_open(read_data=str(sample_schema))
         ), patch(
-            "pandasai.data_loader.loader.DatasetLoader._load_from_source"
-        ) as mock_load_source, patch(
+            "pandasai.data_loader.loader.DatasetLoader._load_from_local_source"
+        ) as mock_load_local_source, patch(
             "pandasai.data_loader.loader.DatasetLoader.load_head"
         ) as mock_load_head:
             loader = DatasetLoader()
@@ -126,7 +127,34 @@ def test_load_from_cache(self, sample_schema):
             assert isinstance(result, DataFrame)
             assert "email" in result.columns
             mock_read_cache.assert_called_once()
-            mock_load_source.assert_not_called()
+            mock_load_local_source.assert_not_called()
+
+    def test_load_from_local_source_valid(self, sample_schema):
+        with patch("os.path.exists", return_value=True), patch(
+            "pandasai.data_loader.loader.DatasetLoader._read_csv_or_parquet"
+        ) as mock_read_csv_or_parquet:
+            loader = DatasetLoader()
+            loader.dataset_path = "test"
+            loader.schema = sample_schema
+
+            mock_read_csv_or_parquet.return_value = DataFrame(
+                {"email": ["[email protected]"]}
+            )
+
+            result = loader._load_from_local_source()
+
+            assert isinstance(result, DataFrame)
+            assert "email" in result.columns
+
+    def test_load_from_local_source_invalid_source_type(self, sample_schema):
+        loader = DatasetLoader()
+        sample_schema["source"]["type"] = "mysql"
+        loader.schema = sample_schema
+
+        with pytest.raises(
+            InvalidDataSourceType, match="Unsupported local source type"
+        ):
+            loader._load_from_local_source()
 
     def test_anonymize_method(self):
         loader = DatasetLoader()