Steve Canny a861ed8fe7
feat(chunk): split tables on even row boundaries (#3504)
**Summary**
Use more sophisticated algorithm for splitting oversized `Table`
elements into `TableChunk` elements during chunking to ensure element
text and HTML are "synchronized" and HTML is always parseable.

**Additional Context**
Table splitting now has the following characteristics:
- `TableChunk.metadata.text_as_html` is always a parseable HTML
`<table>` subtree.
- `TableChunk.text` is always the text in the HTML version of the table
fragment in `.metadata.text_as_html`. Text and HTML are "synchronized".
- The table is divided at a whole-row boundary whenever possible.
- A row is broken at an even-cell boundary when a single row is larger
than the chunking window.
- A cell is broken at an even-word boundary when a single cell is larger
than the chunking window.
- `.text_as_html` is "minified", removing all extraneous whitespace and
unneeded elements or attributes. This maximizes the semantic "density"
of each chunk.
2024-08-19 18:56:53 +00:00

204 lines
7.4 KiB
Python

# pyright: reportPrivateUsage=false
"""Unit-test suite for the `unstructured.common.html_table` module."""
from __future__ import annotations
import pytest
from lxml.html import fragment_fromstring
from unstructured.common.html_table import (
HtmlCell,
HtmlRow,
HtmlTable,
htmlify_matrix_of_cell_texts,
)
class Describe_htmlify_matrix_of_cell_texts:
"""Unit-test suite for `unstructured.common.html_table.htmlify_matrix_of_cell_texts()`."""
def test_htmlify_matrix_handles_empty_cells(self):
assert htmlify_matrix_of_cell_texts([["cell1", "", "cell3"], ["", "cell5", ""]]) == (
"<table>"
"<tr><td>cell1</td><td/><td>cell3</td></tr>"
"<tr><td/><td>cell5</td><td/></tr>"
"</table>"
)
def test_htmlify_matrix_handles_special_characters(self):
assert htmlify_matrix_of_cell_texts([['<>&"', "newline\n"]]) == (
"<table><tr><td>&lt;&gt;&amp;&quot;</td><td>newline<br/></td></tr></table>"
)
def test_htmlify_matrix_handles_multiple_rows_and_cells(self):
assert htmlify_matrix_of_cell_texts([["cell1", "cell2"], ["cell3", "cell4"]]) == (
"<table>"
"<tr><td>cell1</td><td>cell2</td></tr>"
"<tr><td>cell3</td><td>cell4</td></tr>"
"</table>"
)
def test_htmlify_matrix_handles_empty_matrix(self):
assert htmlify_matrix_of_cell_texts([]) == ""
class DescribeHtmlTable:
"""Unit-test suite for `unstructured.common.html_table.HtmlTable`."""
def it_can_construct_from_html_text(self):
html_table = HtmlTable.from_html_text("<table><tr><td>foobar</td></tr></table>")
assert isinstance(html_table, HtmlTable)
assert html_table._table.tag == "table"
@pytest.mark.parametrize(
"html_text",
[
"<table><tr><td>foobar</td></tr></table>",
"<body><table><tr><td>foobar</td></tr></table></body>",
"<html><body><table><tr><td>foobar</td></tr></table></body></html>",
],
)
def it_can_find_a_table_wrapped_in_an_html_or_body_element(self, html_text: str):
html_table = HtmlTable.from_html_text(html_text)
assert isinstance(html_table, HtmlTable)
assert html_table._table.tag == "table"
def but_it_raises_when_no_table_element_is_present_in_the_html(self):
with pytest.raises(ValueError, match="`html_text` contains no `<table>` element"):
HtmlTable.from_html_text("<html><body><tr><td>foobar</td></tr></body></html>")
def it_removes_any_attributes_present_on_the_table_element(self):
html_table = HtmlTable.from_html_text(
'<table border="1", class="foobar"><tr><td>foobar</td></tr></table>',
)
assert html_table.html == "<table><tr><td>foobar</td></tr></table>"
@pytest.mark.parametrize(
"html_text",
[
"<table><thead><tr><td>foobar</td></tr></thead></table>",
"<table><thead><tr><td>foobar</td></tr></thead><tbody></tbody></table>",
"<table><tbody><tr><td>foobar</td></tr></tbody><tfoot></tfoot></table>",
],
)
def it_removes_any_thead_tbody_or_tfoot_elements_present_within_the_table_element(
self, html_text: str
):
html_table = HtmlTable.from_html_text(html_text)
assert html_table.html == "<table><tr><td>foobar</td></tr></table>"
def it_changes_any_th_elements_to_td_elements_for_cell_element_uniformity(self):
html_table = HtmlTable.from_html_text(
"<table>"
" <tr><th>a</th><th/><th>b</th></tr>"
" <tr><td/><td>c</td><td/></tr>"
"</table>"
)
assert html_table.html == (
"<table><tr><td>a</td><td/><td>b</td></tr><tr><td/><td>c</td><td/></tr></table>"
)
def it_removes_any_extra_whitespace_between_elements_and_normalizes_whitespace_in_text(self):
html_table = HtmlTable.from_html_text(
"\n <table>\n <tr>\n <td>\tabc def\nghi </td>\n </tr>\n</table>\n ",
)
assert html_table.html == "<table><tr><td>abc def ghi</td></tr></table>"
def it_can_serialize_the_table_element_to_str_html_text(self):
table = fragment_fromstring("<table><tr><td>foobar</td></tr></table>")
html_table = HtmlTable(table)
assert html_table.html == "<table><tr><td>foobar</td></tr></table>"
def it_can_iterate_the_rows_in_the_table(self):
html_table = HtmlTable.from_html_text(
"<table>"
" <tr><td>abc</td><td>def</td><td>ghi</td></tr>"
" <tr><td>jkl</td><td>mno</td><td>pqr</td></tr>"
" <tr><td>stu</td><td>vwx</td><td>yz</td></tr>"
"</table>"
)
row_iter = html_table.iter_rows()
row = next(row_iter)
assert isinstance(row, HtmlRow)
assert row.html == "<tr><td>abc</td><td>def</td><td>ghi</td></tr>"
# --
row = next(row_iter)
assert isinstance(row, HtmlRow)
assert row.html == "<tr><td>jkl</td><td>mno</td><td>pqr</td></tr>"
# --
row = next(row_iter)
assert isinstance(row, HtmlRow)
assert row.html == "<tr><td>stu</td><td>vwx</td><td>yz</td></tr>"
# --
with pytest.raises(StopIteration):
next(row_iter)
def it_provides_access_to_the_clear_concatenated_text_of_the_table(self):
html_table = HtmlTable.from_html_text(
"<table>"
" <tr><th> a\n b c </th><th/><th>def</th></tr>"
" <tr><td>gh \ti</td><td/><td>\n jk l </td></tr>"
" <tr><td/><td> m n op\n</td><td/></tr>"
"</table>"
)
assert html_table.text == "a b c def gh i jk l m n op"
class DescribeHtmlRow:
"""Unit-test suite for `unstructured.common.html_table.HtmlRow`."""
def it_can_serialize_the_row_to_html(self):
assert HtmlRow(fragment_fromstring("<tr><td>a</td><td>b</td><td/></tr>")).html == (
"<tr><td>a</td><td>b</td><td/></tr>"
)
def it_can_iterate_the_cells_in_the_row(self):
row = HtmlRow(fragment_fromstring("<tr><td>a</td><td>b</td><td/></tr>"))
cell_iter = row.iter_cells()
cell = next(cell_iter)
assert isinstance(cell, HtmlCell)
assert cell.html == "<td>a</td>"
# --
cell = next(cell_iter)
assert isinstance(cell, HtmlCell)
assert cell.html == "<td>b</td>"
# --
cell = next(cell_iter)
assert isinstance(cell, HtmlCell)
assert cell.html == "<td/>"
# --
with pytest.raises(StopIteration):
next(cell_iter)
def it_can_iterate_the_texts_of_the_cells_in_the_row(self):
row = HtmlRow(fragment_fromstring("<tr><td>a</td><td>b</td><td/></tr>"))
text_iter = row.iter_cell_texts()
assert next(text_iter) == "a"
assert next(text_iter) == "b"
with pytest.raises(StopIteration):
next(text_iter)
class DescribeHtmlCell:
"""Unit-test suite for `unstructured.common.html_table.HtmlCell`."""
def it_can_serialize_the_cell_to_html(self):
assert HtmlCell(fragment_fromstring("<td>a b c</td>")).html == "<td>a b c</td>"
@pytest.mark.parametrize(
("cell_html", "expected_value"),
[("<td> Lorem ipsum </td>", "Lorem ipsum"), ("<td/>", "")],
)
def it_knows_the_text_in_the_cell(self, cell_html: str, expected_value: str):
assert HtmlCell(fragment_fromstring(cell_html)).text == expected_value