tests/test_data_fetcher.py

"""
Test cases for data fetching module.
Tests edge cases for yfinance data retrieval.
"""

import unittest
from unittest.mock import patch, MagicMock
import pandas as pd
from src.data_fetcher import (
    _fetch_stock_data_fast,
    get_cached_stock_data,
    fetch_historical_data
)


class TestDataFetcher(unittest.TestCase):
    """Test cases for data fetching functions."""
    
    @patch('src.data_fetcher.yf.Ticker')
    def test_fetch_stock_data_fast_success(self, mock_ticker):
        """Test successful data fetch."""
        # Mock yfinance response
        mock_stock = MagicMock()
        mock_hist = pd.DataFrame({
            'Close': [150, 151],
            'Volume': [1000000, 1100000]
        })
        mock_stock.history.return_value = mock_hist
        mock_ticker.return_value = mock_stock
        
        info, hist = _fetch_stock_data_fast("AAPL")
        
        self.assertIsInstance(info, dict)
        self.assertIn("longName", info)
        self.assertIn("volume", info)
        self.assertFalse(hist.empty)
    
    @patch('src.data_fetcher.yf.Ticker')
    def test_fetch_stock_data_fast_empty(self, mock_ticker):
        """Test data fetch with empty history."""
        mock_stock = MagicMock()
        mock_stock.history.return_value = pd.DataFrame()
        mock_ticker.return_value = mock_stock
        
        info, hist = _fetch_stock_data_fast("INVALID")
        
        self.assertTrue(hist.empty)
        self.assertEqual(info["volume"], 0)
    
    @patch('src.data_fetcher.yf.Ticker')
    def test_fetch_stock_data_fast_exception(self, mock_ticker):
        """Test data fetch with exception."""
        mock_ticker.side_effect = Exception("Network error")
        
        with self.assertRaises(Exception):
            _fetch_stock_data_fast("AAPL")
    
    @patch('src.data_fetcher._fetch_stock_data_fast')
    def test_get_cached_stock_data(self, mock_fetch):
        """Test cached data retrieval."""
        # Mock return value
        mock_info = {"longName": "Apple Inc.", "volume": 1000000}
        mock_hist = pd.DataFrame({'Close': [150], 'Volume': [1000000]})
        mock_fetch.return_value = (mock_info, mock_hist)
        
        # First call should fetch
        info1, hist1 = get_cached_stock_data("AAPL")
        self.assertEqual(mock_fetch.call_count, 1)
        
        # Second call should use cache (if within TTL)
        info2, hist2 = get_cached_stock_data("AAPL")
        # Cache should be used (call count might be same or different based on cache)
        self.assertIsInstance(info2, dict)


if __name__ == '__main__':
    unittest.main()