feat: implement S3 bucket uploader component and unit test (#6146)

* S3 Bucket Uploader, unit test and module init

* [autofix.ci] apply automated fixes

* Updated UT as per feedback

* Added version control fixture

* [autofix.ci] apply automated fixes

* Style changes requested by reviewer

* Really, 1 extra character?

* Ruf styling

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>

src/backend/tests/unit/components/data/test_s3_uploader_component.py

@@ -0,0 +1,136 @@
+import os
+import tempfile
+import uuid
+from pathlib import Path
+
+import boto3
+import pytest
+from langflow.components.data.s3_bucket_uploader import S3BucketUploaderComponent
+from langflow.schema.data import Data
+
+from tests.base import ComponentTestBaseWithoutClient
+
+
+@pytest.mark.skipif(
+    not os.environ.get("AWS_ACCESS_KEY_ID") or not os.environ.get("AWS_SECRET_ACCESS_KEY"),
+    reason="Environment variable AWS_ACCESS_KEY_ID or AWS_SECRET_ACCESS_KEY is not defined.",
+)
+class TestS3UploaderComponent(ComponentTestBaseWithoutClient):
+    """Unit tests for the S3BucketUploaderComponent.
+
+    This test class inherits from ComponentTestBaseWithoutClient and includes several pytest fixtures and a test method
+    to verify the functionality of the S3BucketUploaderComponent.
+
+    Fixtures:
+        component_class: Returns the component class to be tested.
+        file_names_mapping: Returns an empty list since this component doesn't have version-specific files.
+        default_kwargs: Returns an empty dictionary since this component doesn't have any default arguments.
+        temp_files: Creates three temporary files with predefined content and yields them as Data objects.
+        Cleans up the files after the test.
+        s3_bucket: Creates a unique S3 bucket for testing, yields the bucket name, and deletes the bucket
+        and its contents after the test.
+
+    Test Methods:
+        test_upload: Tests the upload functionality of the S3BucketUploaderComponent by uploading temporary files
+        to the S3 bucket and verifying their content.
+    """
+
+    @pytest.fixture
+    def component_class(self):
+        """Return the component class to test."""
+        return S3BucketUploaderComponent
+
+    @pytest.fixture
+    def file_names_mapping(self):
+        """Return an empty list since this component doesn't have version-specific files."""
+
+    @pytest.fixture
+    def default_kwargs(self):
+        """Return an empty dictionary since this component doesn't have any default arguments."""
+        return {}
+
+    @pytest.fixture
+    def temp_files(self):
+        """Setup: Create three temporary files."""
+        temp_files = []
+        contents = [
+            b"Lorem ipsum dolor sit amet, consectetur adipiscing elit.",
+            b"Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.",
+            b"Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris "
+            b"nisi ut aliquip ex ea commodo consequat.",
+        ]
+
+        for content in contents:
+            with tempfile.NamedTemporaryFile(suffix=".txt", delete=False) as temp_file:
+                temp_file.write(content)
+                temp_file.flush()
+                temp_file.close()
+                temp_files.append(temp_file.name)
+
+        data = [
+            Data(data={"file_path": file_path, "text": Path(file_path).read_text(encoding="utf-8")})
+            for file_path in temp_files
+        ]
+
+        yield data
+
+        # Teardown: Explicitly delete the files
+        for temp_file in temp_files:
+            Path(temp_file).unlink()
+
+    @pytest.fixture
+    def s3_bucket(self) -> str:
+        """Generate a unique bucket name (AWS requires globally unique names)."""
+        bucket_name = f"graphrag-test-bucket-{uuid.uuid4().hex[:8]}"
+
+        # Initialize S3 client using environment variables for credentials
+        s3 = boto3.client("s3")
+
+        try:
+            # Create an S3 bucket in your default region
+            s3.create_bucket(Bucket=bucket_name)
+
+            yield bucket_name
+
+        finally:
+            # Teardown: Delete the bucket and its contents
+            try:
+                # List and delete all objects in the bucket
+                objects = s3.list_objects_v2(Bucket=bucket_name).get("Contents", [])
+                for obj in objects:
+                    s3.delete_object(Bucket=bucket_name, Key=obj["Key"])
+
+                # Delete the bucket
+                s3.delete_bucket(Bucket=bucket_name)
+            except boto3.exceptions.Boto3Error as e:
+                pytest.fail(f"Error during teardown: {e}")
+
+    def test_upload(self, temp_files, s3_bucket):
+        """Test uploading files to an S3 bucket."""
+        component = S3BucketUploaderComponent()
+
+        # Set AWS credentials from environment variables
+        aws_access_key_id = os.getenv("AWS_ACCESS_KEY_ID")
+        aws_secret_access_key = os.getenv("AWS_SECRET_ACCESS_KEY")
+        component.set_attributes(
+            {
+                "aws_access_key_id": aws_access_key_id,
+                "aws_secret_access_key": aws_secret_access_key,
+                "bucket_name": s3_bucket,
+                "strategy": "Store Original File",
+                "data_inputs": temp_files,
+                "s3_prefix": "test",
+                "strip_path": True,
+            }
+        )
+
+        component.process_files()
+
+        # Check if the files were uploaded. Assumes key and secret are set via environment variables
+        s3 = boto3.client("s3")
+
+        for temp_file in temp_files:
+            key = f"test/{Path(temp_file.data['file_path']).name}"
+            response = s3.get_object(Bucket=s3_bucket, Key=key)
+            with Path(temp_file.data["file_path"]).open("rb") as f:
+                assert response["Body"].read() == f.read()