test(11-02): add failing tests for stealth integration in ZhihuCrawler

- Test crawler accepts stealth_config parameter
- Test default stealth enabled behavior
- Test stealth can be disabled
- Test _start_browser_with_proxy calls apply_stealth_sync
- Test launch args include --disable-blink-features
- Test backward compatibility

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tests/test_crawler/test_zhihu_crawler_stealth.py

@@ -0,0 +1,165 @@
+"""Integration tests for ZhihuCrawler stealth functionality.
+
+Tests that stealth fingerprint masking is properly integrated
+into ZhihuCrawler's browser initialization.
+"""
+
+import pytest
+from unittest.mock import MagicMock, patch, call
+
+
+class TestZhihuCrawlerStealthIntegration:
+    """Tests for stealth integration in ZhihuCrawler."""
+
+    def test_crawler_has_stealth_config_param(self):
+        """Test that ZhihuCrawler accepts stealth_config parameter."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+        from kb_workflow.crawler.stealth import StealthConfig
+
+        config = StealthConfig(stealth_enabled=False)
+        crawler = ZhihuCrawler(stealth_config=config)
+
+        assert crawler._stealth_config == config
+
+    def test_crawler_default_stealth_enabled(self):
+        """Test that stealth is enabled by default (None = use defaults)."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler()
+
+        # None means use default stealth config (enabled)
+        assert crawler._stealth_config is None
+
+    def test_crawler_can_disable_stealth(self):
+        """Test that stealth can be explicitly disabled."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+        from kb_workflow.crawler.stealth import StealthConfig
+
+        disabled_config = StealthConfig(stealth_enabled=False)
+        crawler = ZhihuCrawler(stealth_config=disabled_config)
+
+        assert crawler._stealth_config.stealth_enabled is False
+
+    @patch('kb_workflow.crawler.zhihu_crawler.sync_playwright')
+    @patch('kb_workflow.crawler.zhihu_crawler.apply_stealth_sync')
+    def test_start_browser_applies_stealth(
+        self,
+        mock_apply_stealth,
+        mock_sync_playwright,
+    ):
+        """Test that _start_browser_with_proxy calls apply_stealth_sync."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        # Setup mocks
+        mock_playwright = MagicMock()
+        mock_browser = MagicMock()
+        mock_context = MagicMock()
+        mock_sync_playwright.return_value.start.return_value = mock_playwright
+        mock_playwright.chromium.launch.return_value = mock_browser
+        mock_browser.new_context.return_value = mock_context
+
+        crawler = ZhihuCrawler()
+        crawler._start_browser_with_proxy(cookie="test_cookie")
+
+        # Verify apply_stealth_sync was called
+        mock_apply_stealth.assert_called_once()
+        call_args = mock_apply_stealth.call_args
+        assert call_args[0][0] == mock_context  # First arg is context
+
+    @patch('kb_workflow.crawler.zhihu_crawler.sync_playwright')
+    @patch('kb_workflow.crawler.zhihu_crawler.apply_stealth_sync')
+    def test_start_browser_launch_args_include_disable_blink_features(
+        self,
+        mock_apply_stealth,
+        mock_sync_playwright,
+    ):
+        """Test that launch includes --disable-blink-features=AutomationControlled."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        # Setup mocks
+        mock_playwright = MagicMock()
+        mock_browser = MagicMock()
+        mock_context = MagicMock()
+        mock_sync_playwright.return_value.start.return_value = mock_playwright
+        mock_playwright.chromium.launch.return_value = mock_browser
+        mock_browser.new_context.return_value = mock_context
+
+        crawler = ZhihuCrawler()
+        crawler._start_browser_with_proxy(cookie="test_cookie")
+
+        # Verify launch was called with correct args
+        launch_call = mock_playwright.chromium.launch
+        launch_call.assert_called_once()
+        call_kwargs = launch_call.call_args[1]
+
+        assert 'args' in call_kwargs
+        assert '--disable-blink-features=AutomationControlled' in call_kwargs['args']
+
+    @patch('kb_workflow.crawler.zhihu_crawler.sync_playwright')
+    @patch('kb_workflow.crawler.zhihu_crawler.apply_stealth_sync')
+    def test_start_browser_stealth_disabled_no_blink_features_arg(
+        self,
+        mock_apply_stealth,
+        mock_sync_playwright,
+    ):
+        """Test that --disable-blink-features is not added when stealth disabled."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+        from kb_workflow.crawler.stealth import StealthConfig
+
+        # Setup mocks
+        mock_playwright = MagicMock()
+        mock_browser = MagicMock()
+        mock_context = MagicMock()
+        mock_sync_playwright.return_value.start.return_value = mock_playwright
+        mock_playwright.chromium.launch.return_value = mock_browser
+        mock_browser.new_context.return_value = mock_context
+
+        disabled_config = StealthConfig(stealth_enabled=False)
+        crawler = ZhihuCrawler(stealth_config=disabled_config)
+        crawler._start_browser_with_proxy(cookie="test_cookie")
+
+        # Verify launch was called without args or with empty/None args
+        launch_call = mock_playwright.chromium.launch
+        call_kwargs = launch_call.call_args[1]
+
+        # When stealth disabled, args should be None or not contain the flag
+        if 'args' in call_kwargs and call_kwargs['args']:
+            assert '--disable-blink-features=AutomationControlled' not in call_kwargs['args']
+
+        # apply_stealth_sync should still be called but with disabled config
+        mock_apply_stealth.assert_called_once()
+
+
+class TestZhihuCrawlerBackwardCompatibility:
+    """Tests for backward compatibility after stealth integration."""
+
+    def test_crawler_works_without_stealth_config(self):
+        """Test that ZhihuCrawler works without explicit stealth_config."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        # Should not raise any errors
+        crawler = ZhihuCrawler(
+            headless=True,
+            timeout=30
+        )
+        assert crawler is not None
+
+    def test_crawler_accepts_all_existing_params(self):
+        """Test that all existing parameters still work."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+        from kb_workflow.crawler.config import CrawlerConfig
+
+        config = CrawlerConfig()
+        crawler = ZhihuCrawler(
+            headless=False,
+            timeout=60,
+            config=config
+        )
+
+        assert crawler.headless is False
+        assert crawler.timeout == 60
+        assert crawler.config == config
+
+
+# Wave 0 completion marker
+WAVE_0_COMPLETE = True