test(08-01): add failing tests for ZhihuCrawler

- Add test_answer_crawler.py with tests for crawl_answer()
- Add test_article_crawler.py with tests for crawl_article()
- Add test_metadata_extraction.py with tests for author/metadata parsing

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

tests/test_crawler/test_metadata_extraction.py

@@ -0,0 +1,109 @@
+"""Tests for metadata extraction from Zhihu API responses"""
+
+import pytest
+
+from kb_workflow.crawler.models import AuthorInfo, ContentMetadata
+
+
+class TestAuthorExtraction:
+    """Tests for author information extraction."""
+
+    def test_parse_author_with_full_data(self):
+        """Test parsing author with all fields present."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+        author_data = {
+            "name": "Test User",
+            "url_token": "test-user-123",
+            "headline": "Test headline"
+        }
+
+        result = crawler._parse_author(author_data)
+
+        assert isinstance(result, AuthorInfo)
+        assert result.name == "Test User"
+        assert result.url_token == "test-user-123"
+        assert result.headline == "Test headline"
+
+    def test_parse_author_with_minimal_data(self):
+        """Test parsing author with only required fields."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+        author_data = {"name": "Minimal User"}
+
+        result = crawler._parse_author(author_data)
+
+        assert result.name == "Minimal User"
+        assert result.url_token is None
+        assert result.headline is None
+
+    def test_parse_author_with_empty_data(self):
+        """Test parsing author with empty/None data."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+
+        result = crawler._parse_author(None)
+        assert result is None
+
+        result = crawler._parse_author({})
+        assert result.name == ""
+
+
+class TestMetadataExtraction:
+    """Tests for content metadata extraction."""
+
+    def test_parse_metadata_with_full_data(self):
+        """Test parsing metadata with all fields present."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+        data = {
+            "author": {"name": "Test Author"},
+            "voteup_count": 100,
+            "comment_count": 20,
+            "created_time": 1700000000,
+            "updated_time": 1700100000
+        }
+
+        result = crawler._parse_metadata(data)
+
+        assert isinstance(result, ContentMetadata)
+        assert result.voteup_count == 100
+        assert result.comment_count == 20
+        assert result.created_time == 1700000000
+        assert result.updated_time == 1700100000
+        assert result.author is not None
+        assert result.author.name == "Test Author"
+
+    def test_parse_metadata_with_defaults(self):
+        """Test parsing metadata with missing optional fields."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+        data = {}
+
+        result = crawler._parse_metadata(data)
+
+        assert result.voteup_count == 0
+        assert result.comment_count == 0
+        assert result.created_time is None
+        assert result.updated_time is None
+        assert result.author is None
+
+    def test_parse_metadata_with_zero_values(self):
+        """Test parsing metadata when counts are zero."""
+        from kb_workflow.crawler.zhihu_crawler import ZhihuCrawler
+
+        crawler = ZhihuCrawler(headless=True, timeout=10)
+        data = {
+            "voteup_count": 0,
+            "comment_count": 0
+        }
+
+        result = crawler._parse_metadata(data)
+
+        assert result.voteup_count == 0
+        assert result.comment_count == 0