🔨 refactor(conftest.py): reformat code for better readability and maintainability

✨ feat(conftest.py): add MyCustomChain class as an example of a custom chain
✨ feat(conftest.py): add CustomChain class as a custom component for building a document
✨ feat(conftest.py): add CSVLoaderComponent class as a custom component for loading CSV files and converting rows to documents

tests/conftest.py

@@ -235,3 +235,33 @@ def custom_chain():
     def build(self, prompt, llm, input: str) -> Document:
         chain = MyCustomChain(prompt=prompt, llm=llm)
         return chain(input)'''
+
+
+@pytest.fixture
+def data_processing():
+    return """import pandas as pd
+from langchain.schema import Document
+from langflow.interface.custom.base import CustomComponent
+
+class CSVLoaderComponent(CustomComponent):
+    display_name: str = "CSV Loader"
+    field_config = {
+        "filename": {"field_type": "str", "required": True},
+        "column_name": {"field_type": "str", "required": True},
+    }
+
+    def build(self, filename: str, column_name: str) -> List[Document]:
+        # Load the CSV file
+        df = pd.read_csv(filename)
+
+        # Verify the column exists
+        if column_name not in df.columns:
+            raise ValueError(f"Column '{column_name}' not found in the CSV file")
+
+        # Convert each row of the specified column to a document object
+        documents = []
+        for content in df[column_name]:
+            metadata = {"filename": filename}
+            documents.append(Document(page_content=str(content), metadata=metadata))
+
+        return documents"""