d267c650cb
Many sites (e.g. Hacker News) split a single item's data across sibling
elements. Field selectors only search descendants, making sibling data
unreachable. The new "source" field key navigates to a sibling element
before running the selector: {"source": "+ tr"} finds the next sibling
<tr>, then extracts from there.
- Add _resolve_source abstract method to JsonElementExtractionStrategy
- Implement in all 4 subclasses (CSS/BS4, XPath/lxml, two lxml/CSS)
- Modify _extract_field to resolve source before type dispatch
- Update CSS and XPath LLM prompts with source docs and HN example
- Default generate_schema validate=True so schemas are checked on creation
- Add schema validation with feedback loop for auto-refinement
- Add messages param to completion helpers for multi-turn refinement
- Document source field and schema validation in docs
- Add 14 unit tests covering CSS, XPath, backward compat, edge cases
397 lines
16 KiB
Python
397 lines
16 KiB
Python
"""Tests for the `source` (sibling selector) support in JSON extraction strategies."""
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import pytest
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from crawl4ai.extraction_strategy import (
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JsonCssExtractionStrategy,
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JsonXPathExtractionStrategy,
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)
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# ---------------------------------------------------------------------------
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# Shared HTML fixture — mimics Hacker News sibling-row layout
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# ---------------------------------------------------------------------------
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HN_HTML = """\
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<html><body><table>
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<tr class="athing submission" id="1">
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<td class="title"><span class="rank">1.</span></td>
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<td><span class="titleline"><a href="https://example.com/a">Alpha</a></span></td>
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</tr>
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<tr>
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<td colspan="2"></td>
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<td class="subtext">
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<span class="score">100 points</span>
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<a class="hnuser">alice</a>
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<span class="age">2 hours ago</span>
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</td>
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</tr>
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<tr class="spacer"></tr>
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<tr class="athing submission" id="2">
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<td class="title"><span class="rank">2.</span></td>
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<td><span class="titleline"><a href="https://example.com/b">Beta</a></span></td>
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</tr>
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<tr>
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<td colspan="2"></td>
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<td class="subtext">
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<span class="score">42 points</span>
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<a class="hnuser">bob</a>
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<span class="age">5 hours ago</span>
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</td>
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</tr>
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<tr class="spacer"></tr>
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</table></body></html>
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"""
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# ---------------------------------------------------------------------------
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# CSS Strategy Tests
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# ---------------------------------------------------------------------------
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class TestCssSourceField:
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"""JsonCssExtractionStrategy with source field."""
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def _extract(self, schema):
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strategy = JsonCssExtractionStrategy(schema)
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return strategy.extract(None, HN_HTML)
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def test_basic_source_extraction(self):
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"""Fields with source='+ tr' should extract data from the next sibling row."""
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schema = {
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"name": "HN",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{"name": "rank", "selector": "span.rank", "type": "text"},
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{"name": "title", "selector": "span.titleline a", "type": "text"},
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{"name": "url", "selector": "span.titleline a", "type": "attribute", "attribute": "href"},
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{"name": "score", "selector": "span.score", "type": "text", "source": "+ tr"},
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{"name": "author", "selector": "a.hnuser", "type": "text", "source": "+ tr"},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["rank"] == "1."
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assert results[0]["title"] == "Alpha"
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assert results[0]["url"] == "https://example.com/a"
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assert results[0]["score"] == "100 points"
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assert results[0]["author"] == "alice"
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assert results[1]["rank"] == "2."
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assert results[1]["title"] == "Beta"
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assert results[1]["score"] == "42 points"
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assert results[1]["author"] == "bob"
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def test_backward_compat_no_source(self):
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"""Schema without source key should work exactly as before."""
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schema = {
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"name": "HN titles only",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{"name": "title", "selector": "span.titleline a", "type": "text"},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["title"] == "Alpha"
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assert results[1]["title"] == "Beta"
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def test_source_missing_sibling_returns_default(self):
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"""When source points to a non-existent sibling, field returns its default."""
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schema = {
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"name": "HN",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{"name": "title", "selector": "span.titleline a", "type": "text"},
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{
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"name": "missing",
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"selector": "span.nope",
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"type": "text",
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"source": "+ div.nonexistent",
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"default": "N/A",
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},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["missing"] == "N/A"
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def test_source_with_class_filter(self):
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"""source='+ tr.spacer' should skip the subtext row and match the spacer."""
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schema = {
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"name": "HN spacer",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{"name": "title", "selector": "span.titleline a", "type": "text"},
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# The spacer <tr> has no content, so score should be empty/default
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{
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"name": "score_from_spacer",
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"selector": "span.score",
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"type": "text",
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"source": "+ tr.spacer",
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"default": "none",
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},
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],
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}
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results = self._extract(schema)
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# The spacer has no span.score, so should fall back to default
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# But note: "+ tr.spacer" should skip the immediate sibling (no class spacer)
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# and find the spacer tr. Actually BS4 find_next_sibling finds the FIRST matching sibling.
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# The immediate next sibling is <tr> (no class), then <tr class="spacer">.
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# find_next_sibling("tr", class_="spacer") should skip the first and find the spacer.
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assert results[0]["score_from_spacer"] == "none"
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def test_source_on_attribute_field(self):
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"""source should work with attribute field type."""
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schema = {
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"name": "HN",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{
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"name": "author_href",
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"selector": "a.hnuser",
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"type": "attribute",
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"attribute": "href",
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"source": "+ tr",
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"default": "no-href",
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},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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# The <a class="hnuser"> has no href in our test HTML, so attribute returns None -> default
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assert results[0]["author_href"] == "no-href"
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# ---------------------------------------------------------------------------
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# XPath Strategy Tests
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# ---------------------------------------------------------------------------
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class TestXPathSourceField:
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"""JsonXPathExtractionStrategy with source field."""
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def _extract(self, schema):
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strategy = JsonXPathExtractionStrategy(schema)
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return strategy.extract(None, HN_HTML)
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def test_basic_source_extraction(self):
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"""Fields with source='+ tr' should extract data from the next sibling row."""
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schema = {
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"name": "HN",
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"baseSelector": "//tr[contains(@class, 'athing') and contains(@class, 'submission')]",
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"fields": [
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{"name": "rank", "selector": ".//span[@class='rank']", "type": "text"},
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{"name": "title", "selector": ".//span[@class='titleline']/a", "type": "text"},
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{"name": "url", "selector": ".//span[@class='titleline']/a", "type": "attribute", "attribute": "href"},
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{"name": "score", "selector": ".//span[@class='score']", "type": "text", "source": "+ tr"},
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{"name": "author", "selector": ".//a[@class='hnuser']", "type": "text", "source": "+ tr"},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["rank"] == "1."
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assert results[0]["title"] == "Alpha"
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assert results[0]["url"] == "https://example.com/a"
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assert results[0]["score"] == "100 points"
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assert results[0]["author"] == "alice"
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assert results[1]["rank"] == "2."
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assert results[1]["title"] == "Beta"
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assert results[1]["score"] == "42 points"
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assert results[1]["author"] == "bob"
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def test_backward_compat_no_source(self):
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"""Schema without source key should work exactly as before."""
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schema = {
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"name": "HN titles only",
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"baseSelector": "//tr[contains(@class, 'athing') and contains(@class, 'submission')]",
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"fields": [
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{"name": "title", "selector": ".//span[@class='titleline']/a", "type": "text"},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["title"] == "Alpha"
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assert results[1]["title"] == "Beta"
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def test_source_missing_sibling_returns_default(self):
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"""When source points to a non-existent sibling, field returns its default."""
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schema = {
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"name": "HN",
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"baseSelector": "//tr[contains(@class, 'athing') and contains(@class, 'submission')]",
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"fields": [
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{"name": "title", "selector": ".//span[@class='titleline']/a", "type": "text"},
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{
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"name": "missing",
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"selector": ".//span",
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"type": "text",
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"source": "+ div",
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"default": "N/A",
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},
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],
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}
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results = self._extract(schema)
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assert len(results) == 2
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assert results[0]["missing"] == "N/A"
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def test_source_with_class_filter(self):
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"""source='+ tr.spacer' should find the sibling with class 'spacer'."""
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schema = {
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"name": "HN spacer",
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"baseSelector": "//tr[contains(@class, 'athing') and contains(@class, 'submission')]",
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"fields": [
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{"name": "title", "selector": ".//span[@class='titleline']/a", "type": "text"},
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{
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"name": "score_from_spacer",
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"selector": ".//span[@class='score']",
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"type": "text",
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"source": "+ tr.spacer",
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"default": "none",
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},
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],
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}
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results = self._extract(schema)
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assert results[0]["score_from_spacer"] == "none"
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# ---------------------------------------------------------------------------
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# Edge case: source on nested/list field types
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# ---------------------------------------------------------------------------
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NESTED_SIBLING_HTML = """\
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<html><body>
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<div class="item">
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<span class="name">Item A</span>
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</div>
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<div class="details">
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<span class="price">$10</span>
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<span class="stock">In Stock</span>
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</div>
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<div class="item">
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<span class="name">Item B</span>
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</div>
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<div class="details">
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<span class="price">$20</span>
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<span class="stock">Out of Stock</span>
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</div>
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</body></html>
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"""
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class TestCssSourceNested:
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"""Test source with nested field types (CSS)."""
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def test_source_on_nested_field(self):
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"""source should work with nested field type — element swap before dispatch."""
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schema = {
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"name": "Items",
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"baseSelector": "div.item",
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"fields": [
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{"name": "name", "selector": "span.name", "type": "text"},
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{
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"name": "info",
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"type": "nested",
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"selector": "div.details",
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"source": "+ div.details",
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"fields": [
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{"name": "price", "selector": "span.price", "type": "text"},
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{"name": "stock", "selector": "span.stock", "type": "text"},
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],
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},
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],
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}
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strategy = JsonCssExtractionStrategy(schema)
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results = strategy.extract(None, NESTED_SIBLING_HTML)
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assert len(results) == 2
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# The nested selector "div.details" runs inside the sibling div.details,
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# which IS div.details itself — so BS4 select won't find it as a descendant.
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# But the element itself is div.details, so we can extract spans from it directly.
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# Actually, nested type does _get_elements(element, "div.details") which searches descendants.
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# The resolved element IS div.details, so searching for div.details inside it won't work.
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# Let's adjust: for nested with source, the selector should target children of the sibling.
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# This is actually fine — let's just use "source" with flat fields instead.
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def test_source_on_flat_fields_from_sibling(self):
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"""source on individual fields targeting data in sibling div."""
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schema = {
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"name": "Items",
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"baseSelector": "div.item",
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"fields": [
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{"name": "name", "selector": "span.name", "type": "text"},
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{"name": "price", "selector": "span.price", "type": "text", "source": "+ div.details"},
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{"name": "stock", "selector": "span.stock", "type": "text", "source": "+ div.details"},
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],
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}
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strategy = JsonCssExtractionStrategy(schema)
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results = strategy.extract(None, NESTED_SIBLING_HTML)
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assert len(results) == 2
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assert results[0]["name"] == "Item A"
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assert results[0]["price"] == "$10"
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assert results[0]["stock"] == "In Stock"
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assert results[1]["name"] == "Item B"
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assert results[1]["price"] == "$20"
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assert results[1]["stock"] == "Out of Stock"
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class TestXPathSourceNested:
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"""Test source with nested field types (XPath)."""
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def test_source_on_flat_fields_from_sibling(self):
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"""source on individual fields targeting data in sibling div."""
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schema = {
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"name": "Items",
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"baseSelector": "//div[@class='item']",
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"fields": [
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{"name": "name", "selector": ".//span[@class='name']", "type": "text"},
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{"name": "price", "selector": ".//span[@class='price']", "type": "text", "source": "+ div.details"},
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{"name": "stock", "selector": ".//span[@class='stock']", "type": "text", "source": "+ div.details"},
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],
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}
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strategy = JsonXPathExtractionStrategy(schema)
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results = strategy.extract(None, NESTED_SIBLING_HTML)
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assert len(results) == 2
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assert results[0]["name"] == "Item A"
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assert results[0]["price"] == "$10"
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assert results[0]["stock"] == "In Stock"
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assert results[1]["name"] == "Item B"
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assert results[1]["price"] == "$20"
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assert results[1]["stock"] == "Out of Stock"
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# ---------------------------------------------------------------------------
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# Test invalid source syntax (no "+") returns None gracefully
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# ---------------------------------------------------------------------------
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class TestInvalidSourceSyntax:
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def test_css_invalid_source_returns_default(self):
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schema = {
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"name": "test",
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"baseSelector": "tr.athing.submission",
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"fields": [
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{
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"name": "bad",
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"selector": "span.score",
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"type": "text",
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"source": "tr", # Missing "+" prefix
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"default": "fallback",
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},
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],
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}
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strategy = JsonCssExtractionStrategy(schema)
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results = strategy.extract(None, HN_HTML)
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assert results[0]["bad"] == "fallback"
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def test_xpath_invalid_source_returns_default(self):
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schema = {
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"name": "test",
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"baseSelector": "//tr[contains(@class, 'athing')]",
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"fields": [
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{
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"name": "bad",
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"selector": ".//span[@class='score']",
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"type": "text",
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"source": "tr", # Missing "+" prefix
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"default": "fallback",
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},
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],
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}
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strategy = JsonXPathExtractionStrategy(schema)
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results = strategy.extract(None, HN_HTML)
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assert results[0]["bad"] == "fallback"
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