FIX #21464 (#21463)

* Reproduce failing behaviour with non-date-time data

* Add a presidio patch for DateTimes

* Fix type-check error

---------

Co-authored-by: Pere Menal <pere.menal@getcollate.io>

ingestion/src/metadata/pii/algorithms/classifiers.py

@@ -38,7 +38,11 @@ from metadata.pii.algorithms.feature_extraction import (
     split_column_name,
 )
 from metadata.pii.algorithms.preprocessing import preprocess_values
-from metadata.pii.algorithms.presidio_patches import url_patcher
+from metadata.pii.algorithms.presidio_patches import (
+    combine_patchers,
+    date_time_patcher,
+    url_patcher,
+)
 from metadata.pii.algorithms.presidio_utils import (
     build_analyzer_engine,
     set_presidio_logger_level,
@@ -119,7 +123,7 @@ class HeuristicPIIClassifier(ColumnClassifier[PIITag]):
             self._presidio_analyzer,
             str_values,
             context=context,
-            recognizer_result_patcher=url_patcher,
+            recognizer_result_patcher=combine_patchers(date_time_patcher, url_patcher),
         )
 
         column_name_matches: Set[PIITag] = set()

ingestion/src/metadata/pii/algorithms/presidio_patches.py

@@ -13,6 +13,7 @@ Patch the Presidio recognizer results to make adapt them to specific use cases.
 """
 from typing import List, Protocol, Sequence
 
+from dateutil.parser import parse
 from presidio_analyzer import RecognizerResult
 
 
@@ -29,6 +30,24 @@ class PresidioRecognizerResultPatcher(Protocol):
         ...
 
 
+def combine_patchers(
+    *patchers: PresidioRecognizerResultPatcher,
+) -> PresidioRecognizerResultPatcher:
+    """
+    Combine multiple patchers into one.
+    This allows us to apply multiple patches in sequence.
+    """
+
+    def combined_patcher(
+        recognizer_results: Sequence[RecognizerResult], text: str
+    ) -> Sequence[RecognizerResult]:
+        for patcher in patchers:
+            recognizer_results = patcher(recognizer_results, text)
+        return recognizer_results
+
+    return combined_patcher
+
+
 def url_patcher(
     recognizer_results: Sequence[RecognizerResult], text: str
 ) -> Sequence[RecognizerResult]:
@@ -43,3 +62,22 @@ def url_patcher(
                 continue
         patched_result.append(result)
     return patched_result
+
+
+def date_time_patcher(
+    recognizer_results: Sequence[RecognizerResult], text: str
+) -> Sequence[RecognizerResult]:
+    """
+    Patch the recognizer result to remove date time false positive with date.
+    """
+    patched_result: List[RecognizerResult] = []
+    for result in recognizer_results:
+        if result.entity_type == "DATE_TIME":
+            # try to parse using dateutils, if it fails, skip the result
+            try:
+                _ = parse(text[result.start : result.end])
+            except ValueError:
+                # if parsing fails, skip the result
+                continue
+        patched_result.append(result)
+    return patched_result

ingestion/tests/unit/pii/algorithms/data/pii_samples.py

@@ -70,6 +70,19 @@ phone_data: LabeledData = {
     "pii_sensitivity": True,
 }
 
+data_time_data: LabeledData = {
+    "column_name": "event_time",
+    "column_data_type": DataType.STRING,
+    "sample_data": [
+        "2023-10-01 12:00:00Z",
+        "2023-10-02 15:30:00Z",
+        "2023-10-03 18:45:00Z",
+        "2023-10-04 21:15:00Z",
+    ],
+    "pii_tags": [PIITag.DATE_TIME],
+    "pii_sensitivity": False,
+}
+
 non_pii_text_data: LabeledData = {
     "column_name": "random_text",
     "column_data_type": DataType.STRING,
@@ -173,8 +186,26 @@ es_nif_data: LabeledData = {
     "sample_data": ["48347544A", "08163649Y", "85738706L", "01922869T", "44729355J"],
     "pii_tags": [
         PIITag.ES_NIF,
-        PIITag.DATE_TIME,
         PIITag.US_DRIVER_LICENSE,  # low score
     ],
     "pii_sensitivity": True,
 }
+
+# Sample data for regression tests
+
+# Previously, this data was incorrectly tagged as PII.DATE_TIME
+false_positive_datetime_data: LabeledData = {
+    "column_name": None,
+    "column_data_type": DataType.STRING,
+    "sample_data": [
+        "60001",
+        "60002",
+        "60003",
+        "60004",
+        "60005",
+        "60006",
+        "60007",
+    ],
+    "pii_tags": [],
+    "pii_sensitivity": False,
+}

ingestion/tests/unit/pii/algorithms/test_feature_extraction.py

@@ -16,7 +16,7 @@ from metadata.pii.algorithms.feature_extraction import (
     extract_pii_tags,
     split_column_name,
 )
-from metadata.pii.algorithms.presidio_patches import url_patcher
+from metadata.pii.algorithms.presidio_patches import date_time_patcher, url_patcher
 from metadata.pii.algorithms.tags import PIITag
 
 
@@ -133,6 +133,30 @@ def test_person_extraction(fake, analyzer):
     )
 
 
+def test_date_time_extraction_false_positive_regression(fake, analyzer):
+    """
+    Regression test for a false positive where a timestamp was incorrectly
+    marked as a date by the Presidio analyzer.
+    """
+    not_dates = [60001, 60002, 60003, 60004, 60005]
+    not_dates_str = [str(date) for date in not_dates]
+    extracted = extract_pii_tags(
+        analyzer, not_dates_str, recognizer_result_patcher=date_time_patcher
+    )
+    assert PIITag.DATE_TIME not in extracted
+
+
+def test_date_time_extraction_with_patched_results(fake, analyzer):
+    # Generate a list of dates and times
+    samples = [str(fake.date_time_this_century()) for _ in range(100)]
+    # Patch the results to avoid false positives
+    extracted = extract_pii_tags(
+        analyzer, samples, recognizer_result_patcher=date_time_patcher
+    )
+
+    assert PIITag.DATE_TIME in extracted
+
+
 # Extraction with patched URL
 def test_email_address_extraction_does_not_extract_url(fake, analyzer):
     samples = [fake.email() for _ in range(100)]