Add configurable data providers and localize frontend UI

backend/tests/test_market_service.py

@@ -157,6 +157,15 @@ class TestPollingPriceManager:
 
         assert manager.api_key == "test_key"
         assert manager.poll_interval == 30
+        assert manager.provider == "finnhub"
+        assert manager.running is False
+
+    def test_init_yfinance(self):
+        manager = PollingPriceManager(provider="yfinance", poll_interval=15)
+
+        assert manager.api_key is None
+        assert manager.poll_interval == 15
+        assert manager.provider == "yfinance"
         assert manager.running is False
 
     def test_subscribe(self):
@@ -182,7 +191,7 @@ class TestPollingPriceManager:
         assert callback in manager.price_callbacks
 
     @patch.object(PollingPriceManager, "_fetch_prices")
-    def test_start_stop(self):
+    def test_start_stop(self, _mock_fetch_prices):
         manager = PollingPriceManager(api_key="test_key", poll_interval=1)
         manager.subscribe(["AAPL"])
 
@@ -246,6 +255,20 @@ class TestMarketService:
         assert service.mock_mode is False
         assert service.api_key == "test_key"
 
+    @patch("backend.services.market.get_data_source", return_value="yfinance")
+    @patch.object(PollingPriceManager, "start")
+    def test_start_real_mode_with_yfinance(self, _mock_start, _mock_source):
+        service = MarketService(
+            tickers=["AAPL"],
+            poll_interval=10,
+            mock_mode=False,
+        )
+
+        service._start_real_mode()
+
+        assert isinstance(service._price_manager, PollingPriceManager)
+        assert service._price_manager.provider == "yfinance"
+
     @pytest.mark.asyncio
     async def test_start_mock_mode(self):
         service = MarketService(
@@ -264,8 +287,9 @@ class TestMarketService:
 
         service.stop()
 
+    @patch("backend.services.market.get_data_source", return_value="finnhub")
     @pytest.mark.asyncio
-    async def test_start_real_mode_without_api_key(self):
+    async def test_start_real_mode_without_api_key(self, _mock_source):
         service = MarketService(
             tickers=["AAPL"],
             mock_mode=False,