Add tests for utils

Author: billyhoce

.gitignore

@@ -1 +1,2 @@
 **/__pycache__/
+.vscode/

services/question-service/requirements.txt

@@ -1,3 +1,6 @@
 fastapi[standard]
 psycopg[binary]
-boto3
+boto3
+pytest
+pytest-asyncio
+moto[s3]

services/question-service/tests/__init__.py

@@ -0,0 +1,108 @@
+import os
+import pytest
+import boto3
+from moto import mock_aws
+from app.utils import upload_to_s3, get_from_s3, delete_from_s3
+
+@pytest.fixture(scope="function")
+def aws_credentials():
+    """Mocked AWS Credentials for moto."""
+    os.environ["AWS_ACCESS_KEY_ID"] = "testing"
+    os.environ["AWS_SECRET_ACCESS_KEY"] = "testing"
+    os.environ["AWS_SECURITY_TOKEN"] = "testing"
+    os.environ["AWS_SESSION_TOKEN"] = "testing"
+    os.environ["AWS_DEFAULT_REGION"] = "us-east-1"
+    os.environ["S3_BUCKET_NAME"] = "test-bucket"
+
+@pytest.fixture(scope="function")
+def mocked_aws(aws_credentials):
+    """
+    Mock all AWS interactions
+    Requires self creation of boto3 clients
+    """
+    with mock_aws():
+        yield
+
+@pytest.fixture
+def mock_image_png():
+    """Fixture for a 1x1 black pixel PNG."""
+    return b'\x89PNG\r\n\x1a\n\x00\x00\x00\rIHDR\x00\x00\x00\x01\x00\x00\x00\x01\x08\x06\x00\x00\x00\x1f\x15\xc4\x89\x00\x00\x00\x0cIDATx\x9cc`\x00\x01\x00\x00\x05\x00\x01\xa2\x99V\xdd\x00\x00\x00\x00IEND\xaeB`\x82'
+
+@pytest.fixture
+def mock_png_s3_keys():
+    return "questions/qid1/0.png"
+
+@pytest.fixture
+def mock_image_jpeg():
+    """Fixture for a 1x1 black pixel JPEG."""
+    jpeg_data = b''.join([
+        b'\xff\xd8',                         # SOI
+        b'\xff\xe0\x00\x10',                 # APP0 segment (JFIF)
+        b'JFIF\x00\x01\x01\x00\x00\x01\x00\x01\x00\x00',
+        b'\xff\xdb\x00C', b'\x00' * 67,      # DQT
+        b'\xff\xc0\x00\x11',                 # SOF0 (baseline DCT)
+        b'\x08\x00\x01\x00\x01\x01\x01\x11\x00',
+        b'\xff\xc4\x00\x14', b'\x00' * 20,   # DHT
+        b'\xff\xda\x00\x0c',                 # SOS
+        b'\x01\x01\x00\x00?\x00',
+        b'\x00\x00',                         # dummy compressed data
+        b'\xff\xd9'                          # EOI
+    ])
+    return jpeg_data
+
+@pytest.fixture
+def mock_jpeg_s3_keys():
+    return "questions/qid2/0.jpeg"
+
+@mock_aws
+def test_upload_to_s3_empty_list():
+    """Tests that upload_to_s3 handles an empty list without error."""
+    try:
+        upload_to_s3([])
+    except Exception as e:
+        pytest.fail(f"upload_to_s3 raised an exception with an empty list: {e}")
+
+@mock_aws
+def test_get_from_s3_empty_list():
+    """Tests that get_from_s3 handles an empty list correctly."""
+    result = get_from_s3([])
+    assert result == []
+
+@mock_aws
+def test_delete_from_s3_empty_list():
+    """Tests that delete_from_s3 handles an empty list without error."""
+    try:
+        delete_from_s3([])
+    except Exception as e:
+        pytest.fail(f"delete_from_s3 raised an exception with an empty list: {e}")
+
+@mock_aws
+def test_s3_upload_get_delete_integration(mocked_aws, mock_image_png, mock_png_s3_keys, mock_image_jpeg, mock_jpeg_s3_keys):
+    """
+    Tests the full upload -> get -> delete cycle with image bytes using fixtures.
+    """
+    s3_client = boto3.client("s3")
+    s3_client.create_bucket(Bucket=os.getenv("S3_BUCKET_NAME"))
+
+    # 1. Upload
+    files_to_upload = [
+        (mock_image_png, mock_png_s3_keys),
+        (mock_image_jpeg, mock_jpeg_s3_keys)
+    ]
+    upload_to_s3(files_to_upload)
+
+    # 2. Get and Verify
+    retrieved_data = get_from_s3([mock_png_s3_keys, mock_jpeg_s3_keys])
+    assert len(retrieved_data) == 2
+    assert retrieved_data[0] == mock_image_png
+    assert retrieved_data[1] == mock_image_jpeg
+
+    # 3. Delete
+    delete_from_s3([mock_png_s3_keys, mock_jpeg_s3_keys])
+
+    # 4. Verify Deletion
+    # Check that getting the objects now raises an error
+    with pytest.raises(s3_client.exceptions.NoSuchKey):
+        s3_client.get_object(Bucket=os.getenv("S3_BUCKET_NAME"), Key=mock_png_s3_keys)
+    with pytest.raises(s3_client.exceptions.NoSuchKey):
+        s3_client.get_object(Bucket=os.getenv("S3_BUCKET_NAME"), Key=mock_jpeg_s3_keys)