Files
paperless-ngx/src/documents/tests/test_classifier.py
T

1020 lines
34 KiB
Python

import re
import warnings
from pathlib import Path
from unittest import mock
import numpy as np
import pytest
from django.conf import settings
from django.test import TestCase
from django.test import override_settings
from documents.classifier import ClassifierModelCorruptError
from documents.classifier import DocumentClassifier
from documents.classifier import IncompatibleClassifierVersionError
from documents.classifier import _predict_with_threshold
from documents.classifier import load_classifier
from documents.models import Correspondent
from documents.models import Document
from documents.models import DocumentType
from documents.models import MatchingModel
from documents.models import StoragePath
from documents.models import Tag
from documents.tests.utils import DirectoriesMixin
from paperless.signed_pickle import HMAC_SIZE
from paperless.signed_pickle import signed_pickle_dumps
def dummy_preprocess(content: str, **kwargs):
"""
Simpler, faster pre-processing for testing purposes
"""
content = content.lower().strip()
content = re.sub(r"\s+", " ", content)
return content
class TestClassifier(DirectoriesMixin, TestCase):
def setUp(self) -> None:
super().setUp()
self.classifier = DocumentClassifier()
self.classifier.preprocess_content = mock.MagicMock(
side_effect=dummy_preprocess,
)
def generate_test_data(self) -> None:
self.c1 = Correspondent.objects.create(
name="c1",
matching_algorithm=Correspondent.MATCH_AUTO,
)
self.c2 = Correspondent.objects.create(name="c2")
self.c3 = Correspondent.objects.create(
name="c3",
matching_algorithm=Correspondent.MATCH_AUTO,
)
self.t1 = Tag.objects.create(
name="t1",
matching_algorithm=Tag.MATCH_AUTO,
pk=12,
)
self.t2 = Tag.objects.create(
name="t2",
matching_algorithm=Tag.MATCH_ANY,
pk=34,
is_inbox_tag=True,
)
self.t3 = Tag.objects.create(
name="t3",
matching_algorithm=Tag.MATCH_AUTO,
pk=45,
)
self.t4 = Tag.objects.create(
name="t4",
matching_algorithm=Tag.MATCH_ANY,
pk=46,
)
self.dt = DocumentType.objects.create(
name="dt",
matching_algorithm=DocumentType.MATCH_AUTO,
)
self.dt2 = DocumentType.objects.create(
name="dt2",
matching_algorithm=DocumentType.MATCH_AUTO,
)
self.sp1 = StoragePath.objects.create(
name="sp1",
path="path1",
matching_algorithm=DocumentType.MATCH_AUTO,
)
self.sp2 = StoragePath.objects.create(
name="sp2",
path="path2",
matching_algorithm=DocumentType.MATCH_AUTO,
)
self.store_paths = [self.sp1, self.sp2]
self.doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
correspondent=self.c1,
checksum="A",
document_type=self.dt,
storage_path=self.sp1,
)
self.doc2 = Document.objects.create(
title="doc1",
content="this is another document, but from c2",
correspondent=self.c2,
checksum="B",
)
self.doc_inbox = Document.objects.create(
title="doc235",
content="aa",
checksum="C",
)
self.doc1.tags.add(self.t1)
self.doc2.tags.add(self.t1)
self.doc2.tags.add(self.t3)
self.doc_inbox.tags.add(self.t2)
def generate_train_and_save(self) -> None:
"""
Generates the training data, trains and saves the updated pickle
file. This ensures the test is using the same scikit learn version
and eliminates a warning from the test suite
"""
self.generate_test_data()
self.classifier.train()
self.classifier.save()
def test_no_training_data(self) -> None:
"""
GIVEN:
- No documents exist to train
WHEN:
- Classifier training is requested
THEN:
- Exception is raised
"""
with self.assertRaisesMessage(ValueError, "No training data available."):
self.classifier.train()
def test_no_non_inbox_tags(self) -> None:
"""
GIVEN:
- No documents without an inbox tag exist
WHEN:
- Classifier training is requested
THEN:
- Exception is raised
"""
t1 = Tag.objects.create(
name="t1",
matching_algorithm=Tag.MATCH_ANY,
pk=34,
is_inbox_tag=True,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
doc1.tags.add(t1)
with self.assertRaisesMessage(ValueError, "No training data available."):
self.classifier.train()
def testEmpty(self) -> None:
"""
GIVEN:
- A document exists
- No tags/not enough data to predict
WHEN:
- Classifier prediction is requested
THEN:
- Classifier returns no predictions
"""
Document.objects.create(title="WOW", checksum="3457", content="ASD")
self.classifier.train()
self.assertIsNone(self.classifier.document_type_classifier)
self.assertIsNone(self.classifier.tags_classifier)
self.assertIsNone(self.classifier.correspondent_classifier)
self.assertListEqual(self.classifier.predict_tags(""), [])
self.assertIsNone(self.classifier.predict_document_type(""))
self.assertIsNone(self.classifier.predict_correspondent(""))
def testTrain(self) -> None:
"""
GIVEN:
- Test data
WHEN:
- Classifier is trained
THEN:
- Classifier uses correct values for correspondent learning
- Classifier uses correct values for tags learning
"""
self.generate_test_data()
self.classifier.train()
self.assertListEqual(
list(self.classifier.correspondent_classifier.classes_),
[-1, self.c1.pk],
)
self.assertListEqual(
list(self.classifier.tags_binarizer.classes_),
[self.t1.pk, self.t3.pk],
)
def testPredict(self) -> None:
"""
GIVEN:
- Classifier trained against test data
WHEN:
- Prediction requested for correspondent, tags, type
THEN:
- Expected predictions based on training set
"""
self.generate_test_data()
self.classifier.train()
with (
mock.patch.object(
self.classifier.data_vectorizer,
"transform",
wraps=self.classifier.data_vectorizer.transform,
) as mock_transform,
mock.patch.object(
self.classifier,
"preprocess_content",
wraps=self.classifier.preprocess_content,
) as mock_preprocess_content,
):
self.assertEqual(
self.classifier.predict_correspondent(self.doc1.content),
self.c1.pk,
)
self.assertEqual(
self.classifier.predict_correspondent(self.doc2.content),
None,
)
self.assertListEqual(
self.classifier.predict_tags(self.doc1.content),
[self.t1.pk],
)
self.assertListEqual(
self.classifier.predict_tags(self.doc2.content),
[self.t1.pk, self.t3.pk],
)
self.assertEqual(
self.classifier.predict_document_type(self.doc1.content),
self.dt.pk,
)
self.assertEqual(
self.classifier.predict_document_type(self.doc2.content),
None,
)
# Check that the classifier vectorized content and text preprocessing has been cached
# It should be called once per document (doc1 and doc2)
self.assertEqual(mock_preprocess_content.call_count, 2)
self.assertEqual(mock_transform.call_count, 2)
def test_vectorize_recomputes_tampered_cache_entry(self) -> None:
cached = bytearray(signed_pickle_dumps(["cached vector"]))
cached[HMAC_SIZE] ^= 0xFF
self.classifier.data_vectorizer = mock.Mock()
self.classifier.data_vectorizer.transform.return_value = ["fresh vector"]
with (
mock.patch(
"documents.classifier.read_cache.get",
return_value=bytes(cached),
),
mock.patch("documents.classifier.read_cache.set") as cache_set,
mock.patch("documents.classifier.read_cache.touch") as cache_touch,
):
result = self.classifier._vectorize("content")
self.assertEqual(result, ["fresh vector"])
self.classifier.data_vectorizer.transform.assert_called_once()
cache_set.assert_called_once()
cache_touch.assert_not_called()
def test_no_retrain_if_no_change(self) -> None:
"""
GIVEN:
- Classifier trained with current data
WHEN:
- Classifier training is requested again
THEN:
- Classifier does not redo training
"""
self.generate_test_data()
self.assertTrue(self.classifier.train())
self.assertFalse(self.classifier.train())
def test_retrain_if_change(self) -> None:
"""
GIVEN:
- Classifier trained with current data
WHEN:
- Classifier training is requested again
- Documents have changed
THEN:
- Classifier does not redo training
"""
self.generate_test_data()
self.assertTrue(self.classifier.train())
self.doc1.correspondent = self.c2
self.doc1.save()
self.assertTrue(self.classifier.train())
def test_retrain_if_auto_match_set_changed(self) -> None:
"""
GIVEN:
- Classifier trained with current data
WHEN:
- Classifier training is requested again
- Some new AUTO match object exists
THEN:
- Classifier does redo training
"""
self.generate_test_data()
# Add the ANY type
self.doc1.tags.add(self.t4)
self.assertTrue(self.classifier.train())
# Change the matching type
self.t4.matching_algorithm = MatchingModel.MATCH_AUTO
self.t4.save()
self.assertTrue(self.classifier.train())
def testVersionIncreased(self) -> None:
"""
GIVEN:
- Existing classifier model saved at a version
WHEN:
- Attempt to load classifier file from newer version
THEN:
- Exception is raised
"""
self.generate_train_and_save()
classifier2 = DocumentClassifier()
current_ver = DocumentClassifier.FORMAT_VERSION
with mock.patch(
"documents.classifier.DocumentClassifier.FORMAT_VERSION",
current_ver + 1,
):
# assure that we won't load old classifiers.
self.assertRaises(IncompatibleClassifierVersionError, classifier2.load)
self.classifier.save()
# assure that we can load the classifier after saving it.
classifier2.load()
def testSaveClassifier(self) -> None:
self.generate_train_and_save()
new_classifier = DocumentClassifier()
new_classifier.load()
new_classifier.preprocess_content = mock.MagicMock(side_effect=dummy_preprocess)
self.assertFalse(new_classifier.train())
def test_load_and_classify(self) -> None:
self.generate_train_and_save()
new_classifier = DocumentClassifier()
new_classifier.load()
new_classifier.preprocess_content = mock.MagicMock(side_effect=dummy_preprocess)
self.assertCountEqual(new_classifier.predict_tags(self.doc2.content), [45, 12])
def test_load_corrupt_file(self) -> None:
"""
GIVEN:
- Corrupted classifier pickle file
WHEN:
- An attempt is made to load the classifier
THEN:
- The ClassifierModelCorruptError is raised
"""
self.generate_train_and_save()
# Write garbage data (valid HMAC length but invalid content)
Path(settings.MODEL_FILE).write_bytes(b"\x00" * 64)
with self.assertRaises(ClassifierModelCorruptError):
self.classifier.load()
self.assertIsNone(load_classifier())
def test_load_corrupt_pickle_valid_hmac(self) -> None:
"""
GIVEN:
- A classifier file with valid HMAC but unparsable pickle data
WHEN:
- An attempt is made to load the classifier
THEN:
- The ClassifierModelCorruptError is raised
"""
garbage_data = b"this is not valid pickle data"
signature = DocumentClassifier._compute_hmac(garbage_data)
Path(settings.MODEL_FILE).write_bytes(signature + garbage_data)
with self.assertRaises(ClassifierModelCorruptError):
self.classifier.load()
def test_load_tampered_file(self) -> None:
"""
GIVEN:
- A classifier model file whose data has been modified
WHEN:
- An attempt is made to load the classifier
THEN:
- The ClassifierModelCorruptError is raised due to HMAC mismatch
"""
self.generate_train_and_save()
raw = Path(settings.MODEL_FILE).read_bytes()
# Flip a byte in the data portion (after the 32-byte HMAC)
tampered = raw[:32] + bytes([raw[32] ^ 0xFF]) + raw[33:]
Path(settings.MODEL_FILE).write_bytes(tampered)
with self.assertRaises(ClassifierModelCorruptError):
self.classifier.load()
def test_load_wrong_secret_key(self) -> None:
"""
GIVEN:
- A classifier model file signed with a different SECRET_KEY
WHEN:
- An attempt is made to load the classifier
THEN:
- The ClassifierModelCorruptError is raised due to HMAC mismatch
"""
self.generate_train_and_save()
with override_settings(SECRET_KEY="different-secret-key"):
with self.assertRaises(ClassifierModelCorruptError):
self.classifier.load()
def test_load_truncated_file(self) -> None:
"""
GIVEN:
- A classifier model file that is too short to contain an HMAC
WHEN:
- An attempt is made to load the classifier
THEN:
- The ClassifierModelCorruptError is raised
"""
Path(settings.MODEL_FILE).write_bytes(b"\x00" * 16)
with self.assertRaises(ClassifierModelCorruptError):
self.classifier.load()
def test_load_new_scikit_learn_version(self) -> None:
"""
GIVEN:
- classifier pickle file triggers an InconsistentVersionWarning
WHEN:
- An attempt is made to load the classifier
THEN:
- IncompatibleClassifierVersionError is raised
"""
from sklearn.exceptions import InconsistentVersionWarning
self.generate_train_and_save()
fake_warning = warnings.WarningMessage(
message=InconsistentVersionWarning(
estimator_name="MLPClassifier",
current_sklearn_version="1.0",
original_sklearn_version="0.9",
),
category=InconsistentVersionWarning,
filename="",
lineno=0,
)
real_catch_warnings = warnings.catch_warnings
class PatchedCatchWarnings(real_catch_warnings):
def __enter__(self):
w = super().__enter__()
w.append(fake_warning)
return w
with mock.patch(
"documents.classifier.warnings.catch_warnings",
PatchedCatchWarnings,
):
with self.assertRaises(IncompatibleClassifierVersionError):
self.classifier.load()
def test_one_correspondent_predict(self) -> None:
c1 = Correspondent.objects.create(
name="c1",
matching_algorithm=Correspondent.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
correspondent=c1,
checksum="A",
)
self.classifier.train()
self.assertEqual(self.classifier.predict_correspondent(doc1.content), c1.pk)
def test_one_correspondent_predict_manydocs(self) -> None:
c1 = Correspondent.objects.create(
name="c1",
matching_algorithm=Correspondent.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
correspondent=c1,
checksum="A",
)
doc2 = Document.objects.create(
title="doc2",
content="this is a document from no one",
checksum="B",
)
self.classifier.train()
self.assertEqual(self.classifier.predict_correspondent(doc1.content), c1.pk)
self.assertIsNone(self.classifier.predict_correspondent(doc2.content))
def test_one_type_predict(self) -> None:
dt = DocumentType.objects.create(
name="dt",
matching_algorithm=DocumentType.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
document_type=dt,
)
self.classifier.train()
self.assertEqual(self.classifier.predict_document_type(doc1.content), dt.pk)
def test_one_type_predict_manydocs(self) -> None:
dt = DocumentType.objects.create(
name="dt",
matching_algorithm=DocumentType.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
document_type=dt,
)
doc2 = Document.objects.create(
title="doc1",
content="this is a document from c2",
checksum="B",
)
self.classifier.train()
self.assertEqual(self.classifier.predict_document_type(doc1.content), dt.pk)
self.assertIsNone(self.classifier.predict_document_type(doc2.content))
def test_one_path_predict(self) -> None:
sp = StoragePath.objects.create(
name="sp",
matching_algorithm=StoragePath.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
storage_path=sp,
)
self.classifier.train()
self.assertEqual(self.classifier.predict_storage_path(doc1.content), sp.pk)
def test_one_path_predict_manydocs(self) -> None:
sp = StoragePath.objects.create(
name="sp",
matching_algorithm=StoragePath.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
storage_path=sp,
)
doc2 = Document.objects.create(
title="doc1",
content="this is a document from c2",
checksum="B",
)
self.classifier.train()
self.assertEqual(self.classifier.predict_storage_path(doc1.content), sp.pk)
self.assertIsNone(self.classifier.predict_storage_path(doc2.content))
def test_predict_rejects_prediction_below_match_threshold(self) -> None:
"""
GIVEN:
- Classifiers trained against test data with confident predictions
WHEN:
- CLASSIFIER_MATCH_THRESHOLD exceeds the model's confidence
THEN:
- Every predict_* method discards the match in favor of no match
"""
c1 = Correspondent.objects.create(
name="c1",
matching_algorithm=Correspondent.MATCH_AUTO,
)
dt1 = DocumentType.objects.create(
name="dt1",
matching_algorithm=DocumentType.MATCH_AUTO,
)
sp1 = StoragePath.objects.create(
name="sp1",
matching_algorithm=StoragePath.MATCH_AUTO,
)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
correspondent=c1,
document_type=dt1,
storage_path=sp1,
checksum="A",
)
Document.objects.create(
title="doc2",
content="this is a document from no one",
checksum="B",
)
self.classifier.train()
predictors = {
"correspondent": self.classifier.predict_correspondent,
"document_type": self.classifier.predict_document_type,
"storage_path": self.classifier.predict_storage_path,
}
# No real prediction can reach a confidence this high, so this
# isolates the threshold check from the model's actual output.
with override_settings(CLASSIFIER_MATCH_THRESHOLD=0.999999):
for name, predict in predictors.items():
with self.subTest(field=name):
self.assertIsNone(predict(doc1.content))
def test_train_uses_balanced_sample_weight(self) -> None:
"""
GIVEN:
- A training set with correspondents, document types and storage paths
WHEN:
- The classifier is trained
THEN:
- Each MLP classifier is fit with balanced sample weights, so that
over-represented classes don't dominate predictions
"""
c1 = Correspondent.objects.create(
name="c1",
matching_algorithm=Correspondent.MATCH_AUTO,
)
dt1 = DocumentType.objects.create(
name="dt1",
matching_algorithm=DocumentType.MATCH_AUTO,
)
sp1 = StoragePath.objects.create(
name="sp1",
matching_algorithm=StoragePath.MATCH_AUTO,
)
Document.objects.create(
title="doc1",
content="this is a document from c1",
correspondent=c1,
document_type=dt1,
storage_path=sp1,
checksum="A",
)
Document.objects.create(
title="doc2",
content="this is a document from no one",
checksum="B",
)
with mock.patch(
"sklearn.utils.class_weight.compute_sample_weight",
return_value=None,
) as mocked_compute_sample_weight:
self.classifier.train()
self.assertEqual(mocked_compute_sample_weight.call_count, 3)
for call in mocked_compute_sample_weight.call_args_list:
self.assertEqual(call.args[0], "balanced")
def test_one_tag_predict(self) -> None:
t1 = Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
doc1.tags.add(t1)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc1.content), [t1.pk])
def test_one_tag_predict_unassigned(self) -> None:
Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc1.content), [])
def test_two_tags_predict_singledoc(self) -> None:
t1 = Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
t2 = Tag.objects.create(name="t2", matching_algorithm=Tag.MATCH_AUTO, pk=121)
doc4 = Document.objects.create(
title="doc1",
content="this is a document from c4",
checksum="D",
)
doc4.tags.add(t1)
doc4.tags.add(t2)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc4.content), [t1.pk, t2.pk])
def test_two_tags_predict(self) -> None:
t1 = Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
t2 = Tag.objects.create(name="t2", matching_algorithm=Tag.MATCH_AUTO, pk=121)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
doc2 = Document.objects.create(
title="doc1",
content="this is a document from c2",
checksum="B",
)
doc3 = Document.objects.create(
title="doc1",
content="this is a document from c3",
checksum="C",
)
doc4 = Document.objects.create(
title="doc1",
content="this is a document from c4",
checksum="D",
)
doc1.tags.add(t1)
doc2.tags.add(t2)
doc4.tags.add(t1)
doc4.tags.add(t2)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc1.content), [t1.pk])
self.assertListEqual(self.classifier.predict_tags(doc2.content), [t2.pk])
self.assertListEqual(self.classifier.predict_tags(doc3.content), [])
self.assertListEqual(self.classifier.predict_tags(doc4.content), [t1.pk, t2.pk])
def test_one_tag_predict_multi(self) -> None:
t1 = Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
doc2 = Document.objects.create(
title="doc2",
content="this is a document from c2",
checksum="B",
)
doc1.tags.add(t1)
doc2.tags.add(t1)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc1.content), [t1.pk])
self.assertListEqual(self.classifier.predict_tags(doc2.content), [t1.pk])
def test_one_tag_predict_multi_2(self) -> None:
t1 = Tag.objects.create(name="t1", matching_algorithm=Tag.MATCH_AUTO, pk=12)
doc1 = Document.objects.create(
title="doc1",
content="this is a document from c1",
checksum="A",
)
doc2 = Document.objects.create(
title="doc2",
content="this is a document from c2",
checksum="B",
)
doc1.tags.add(t1)
self.classifier.train()
self.assertListEqual(self.classifier.predict_tags(doc1.content), [t1.pk])
self.assertListEqual(self.classifier.predict_tags(doc2.content), [])
def test_load_classifier_not_exists(self) -> None:
self.assertFalse(Path(settings.MODEL_FILE).exists())
self.assertIsNone(load_classifier())
@mock.patch("documents.classifier.DocumentClassifier.load")
def test_load_classifier(self, load) -> None:
Path(settings.MODEL_FILE).touch()
self.assertIsNotNone(load_classifier())
load.assert_called_once()
@override_settings(
CACHES={
"default": {"BACKEND": "django.core.cache.backends.locmem.LocMemCache"},
},
)
@override_settings(
MODEL_FILE=str(Path(__file__).parent / "data" / "model.pickle"),
)
@pytest.mark.skip(
reason="Disabled caching due to high memory usage - need to investigate.",
)
def test_load_classifier_cached(self) -> None:
classifier = load_classifier()
self.assertIsNotNone(classifier)
with mock.patch("documents.classifier.DocumentClassifier.load") as load:
load_classifier()
load.assert_not_called()
@mock.patch("documents.classifier.DocumentClassifier.load")
def test_load_classifier_incompatible_version(self, load) -> None:
Path(settings.MODEL_FILE).touch()
self.assertTrue(Path(settings.MODEL_FILE).exists())
load.side_effect = IncompatibleClassifierVersionError("Dummy Error")
self.assertIsNone(load_classifier())
self.assertFalse(Path(settings.MODEL_FILE).exists())
@mock.patch("documents.classifier.DocumentClassifier.load")
def test_load_classifier_os_error(self, load) -> None:
Path(settings.MODEL_FILE).touch()
self.assertTrue(Path(settings.MODEL_FILE).exists())
load.side_effect = OSError()
self.assertIsNone(load_classifier())
self.assertTrue(Path(settings.MODEL_FILE).exists())
@mock.patch("documents.classifier.DocumentClassifier.load")
def test_load_classifier_raise_exception(self, mock_load) -> None:
Path(settings.MODEL_FILE).touch()
mock_load.side_effect = IncompatibleClassifierVersionError("Dummy Error")
with self.assertRaises(IncompatibleClassifierVersionError):
load_classifier(raise_exception=True)
Path(settings.MODEL_FILE).touch()
mock_load.side_effect = ClassifierModelCorruptError()
with self.assertRaises(ClassifierModelCorruptError):
load_classifier(raise_exception=True)
Path(settings.MODEL_FILE).touch()
mock_load.side_effect = OSError()
with self.assertRaises(OSError):
load_classifier(raise_exception=True)
Path(settings.MODEL_FILE).touch()
mock_load.side_effect = Exception()
with self.assertRaises(Exception):
load_classifier(raise_exception=True)
class _StubProbaClassifier:
"""
A fake scikit-learn classifier exposing just enough of the API for
`_predict_with_threshold`: `classes_` and `predict_proba`.
"""
def __init__(self, classes: list[int], probabilities: list[float]) -> None:
self.classes_ = np.array(classes)
self._probabilities = np.array([probabilities])
def predict_proba(self, X) -> np.ndarray:
return self._probabilities
@pytest.mark.parametrize(
("classes", "probabilities", "threshold", "expected"),
[
# confident prediction above the threshold is returned
([-1, 3], [0.1, 0.9], 0.6, 3),
# prediction below the threshold is discarded
([-1, 3], [0.45, 0.55], 0.6, None),
# boundary: exactly at the threshold is accepted, not discarded
([-1, 3], [0.4, 0.6], 0.6, 3),
# the winning class is the "no match" pseudo-class, regardless of its
# own confidence
([-1, 3], [0.99, 0.01], 0.0, None),
# threshold of 0.0 disables the confidence check entirely
([-1, 3], [0.45, 0.55], 0.0, 3),
],
)
def test_predict_with_threshold(classes, probabilities, threshold, expected) -> None:
classifier = _StubProbaClassifier(classes, probabilities)
result = _predict_with_threshold(classifier, X=None, threshold=threshold)
assert result == expected
def test_classifier_match_threshold_default() -> None:
"""
GIVEN:
- No PAPERLESS_CLASSIFIER_MATCH_THRESHOLD environment variable is set
THEN:
- The classifier match threshold defaults to 0.6
"""
assert settings.CLASSIFIER_MATCH_THRESHOLD == 0.6
def test_preprocess_content() -> None:
"""
GIVEN:
- Advanced text processing is enabled (default)
WHEN:
- Classifier preprocesses a document's content
THEN:
- Processed content matches the expected output (stemmed words)
"""
with (Path(__file__).parent / "samples" / "content.txt").open("r") as f:
content = f.read()
with (Path(__file__).parent / "samples" / "preprocessed_content_advanced.txt").open(
"r",
) as f:
expected_preprocess_content = f.read().rstrip()
classifier = DocumentClassifier()
result = classifier.preprocess_content(content)
assert result == expected_preprocess_content
def test_preprocess_content_nltk_disabled() -> None:
"""
GIVEN:
- Advanced text processing is disabled
WHEN:
- Classifier preprocesses a document's content
THEN:
- Processed content matches the expected output (unstemmed words)
"""
with (Path(__file__).parent / "samples" / "content.txt").open("r") as f:
content = f.read()
with (Path(__file__).parent / "samples" / "preprocessed_content.txt").open(
"r",
) as f:
expected_preprocess_content = f.read().rstrip()
classifier = DocumentClassifier()
with mock.patch("documents.classifier.ADVANCED_TEXT_PROCESSING_ENABLED", new=False):
result = classifier.preprocess_content(content)
assert result == expected_preprocess_content
def test_preprocess_content_nltk_load_fail(mocker) -> None:
"""
GIVEN:
- NLTK stop words fail to load
WHEN:
- Classifier preprocesses a document's content
THEN:
- Processed content matches the expected output (unstemmed words)
"""
_module = mocker.MagicMock(name="nltk_corpus_mock")
_module.stopwords.words.side_effect = AttributeError()
mocker.patch.dict("sys.modules", {"nltk.corpus": _module})
classifier = DocumentClassifier()
with (Path(__file__).parent / "samples" / "content.txt").open("r") as f:
content = f.read()
with (Path(__file__).parent / "samples" / "preprocessed_content.txt").open(
"r",
) as f:
expected_preprocess_content = f.read().rstrip()
result = classifier.preprocess_content(content)
assert result == expected_preprocess_content