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mcp-nextcloud/tests/unit/test_doc_classifier.py
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Chris CoutinhoandClaude Opus 4.8 4bdb0bc6d6 fix(review): warn (not debug) on shadow-classify failure; tidy pymupdf usage
Address PR #855 round 2:

- 🔴 _shadow_classify swallowed all exceptions at DEBUG, so a systematic
  failure (pymupdf bug, memory pressure) is invisible at LOG_LEVEL=INFO and
  trips SonarQube S2221/S5754. Log at WARNING instead (still best-effort --
  indexing is unaffected).
- classifier: use `with pymupdf.open(...) as doc` instead of manual try/finally.
- tests: release the Pixmap's native memory (del pix) in the image fixtures.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-05 00:22:17 +02:00

131 lines
4.1 KiB
Python

"""Unit tests for the tier-0 document classifier.
Pins the routing decisions and the text-quality heuristic that drive which
extraction tier a PDF starts in:
* a clean born-digital PDF (text, no full-page images) -> ``fast`` (tier 1);
* a full-page-image scan -> ``ocr`` (tier 3), since handwriting/stamps aren't
in any text layer;
* the text-quality score distinguishes clean prose from mashed/space-less junk.
"""
import pymupdf
import pytest
from nextcloud_mcp_server.document_processors import classifier as clf
pytestmark = pytest.mark.unit
def _digital_pdf(
pages: int = 3, body: str = "Hello world this is clean text. "
) -> bytes:
doc = pymupdf.open()
for _ in range(pages):
page = doc.new_page(width=595, height=842)
page.insert_text((50, 60), body * 8)
data: bytes = doc.tobytes()
doc.close()
return data
def _full_page_image_pdf(pages: int = 2) -> bytes:
# A page whose entire area is a raster image -> looks scanned.
doc = pymupdf.open()
pix = pymupdf.Pixmap(pymupdf.csRGB, pymupdf.IRect(0, 0, 600, 850))
pix.clear_with(255)
img = pix.tobytes("png")
del pix # Pixmap holds native memory; release it before the loop
for _ in range(pages):
page = doc.new_page(width=595, height=842)
page.insert_image(page.rect, stream=img)
data: bytes = doc.tobytes()
doc.close()
return data
# --- text-quality heuristic --------------------------------------------------
def test_text_quality_clean_prose_scores_high():
assert clf._text_quality("the quick brown fox jumps over the lazy dog") > 0.8
def test_text_quality_mashed_tokens_scores_low():
# space-less / mashed layer (the "Student 147" failure mode)
mashed = "01322234567mobileoutstandingresilienceacademicachievementhurdles"
assert clf._text_quality(mashed) < clf.MIN_TEXT_QUALITY
def test_text_quality_empty_is_zero():
assert clf._text_quality("") == 0.0
# --- routing -----------------------------------------------------------------
def test_digital_pdf_routes_fast():
c = clf.classify_pdf(_digital_pdf())
assert c.recommended_tier == "fast"
assert c.ocr_page_fraction == 0.0
assert "image_heavy" not in c.flags
assert c.mean_text_quality > 0.8
def test_full_page_image_routes_ocr():
c = clf.classify_pdf(_full_page_image_pdf())
assert c.recommended_tier == "ocr"
assert c.ocr_page_fraction == 1.0
assert "image_heavy" in c.flags
# --- sampling bounds large docs ----------------------------------------------
def test_large_doc_is_sampled():
c = clf.classify_pdf(_digital_pdf(pages=120))
assert c.page_count == 120
assert c.sampled_pages <= clf.MAX_SAMPLED_PAGES
def test_sample_indices_includes_first_and_last_page():
idx = clf._sample_indices(100)
assert idx[0] == 0
assert idx[-1] == 99 # last page must be sampled (scanned-tail case)
assert len(idx) <= clf.MAX_SAMPLED_PAGES
# --- flag paths --------------------------------------------------------------
def _image_with_mashed_text_pdf(pages: int = 2) -> bytes:
# Full-page image with a junk (mashed/space-less) text layer over it -- a
# scan whose OCR'd text layer is unusable.
doc = pymupdf.open()
pix = pymupdf.Pixmap(pymupdf.csRGB, pymupdf.IRect(0, 0, 600, 850))
pix.clear_with(255)
img = pix.tobytes("png")
del pix # Pixmap holds native memory; release it before the loop
mashed = "01322234567mobileoutstandingresilienceacademicachievement " * 3
for _ in range(pages):
page = doc.new_page(width=595, height=842)
page.insert_image(page.rect, stream=img)
page.insert_text((50, 60), mashed)
data: bytes = doc.tobytes()
doc.close()
return data
def test_scanned_flag_when_no_text_layer():
c = clf.classify_pdf(_full_page_image_pdf())
assert c.total_chars == 0
assert "scanned" in c.flags
assert c.recommended_tier == "ocr"
def test_bad_text_layer_flag_on_image_with_junk_text():
c = clf.classify_pdf(_image_with_mashed_text_pdf())
assert c.total_chars > 0
assert c.mean_text_quality < clf.MIN_TEXT_QUALITY
assert "bad_text_layer" in c.flags
assert c.recommended_tier == "ocr"