From 8a5fab4898675cac865f1202ddaa11f197e158d3 Mon Sep 17 00:00:00 2001
From: Aaron Loo <aaronloo@yelp.com>
Date: Sat, 3 Apr 2021 10:01:21 -0700
Subject: [PATCH] bug fix: clearing filter caches upon loading new settings

---
 detect_secrets/settings.py         | 34 ++++++++++++++++++++++++++++--
 tests/filters/regex_filter_test.py | 16 ++++++++++++++
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/detect_secrets/settings.py b/detect_secrets/settings.py
index 1098ac055..6218eb39c 100644
--- a/detect_secrets/settings.py
+++ b/detect_secrets/settings.py
@@ -88,10 +88,40 @@ def transient_settings(config: Dict[str, Any]) -> Generator['Settings', None, No
 
 
 def cache_bust() -> None:
-    get_settings.cache_clear()
-    get_filters.cache_clear()
     get_plugins.cache_clear()
 
+    get_filters.cache_clear()
+    for path, config in get_settings().filters.items():
+        # Need to also clear the individual caches (e.g. cached regex patterns).
+        parts = urlparse(path)
+        if not parts.scheme:
+            module_path, _ = path.rsplit('.', 1)
+            try:
+                module = import_module(module_path)
+            except ModuleNotFoundError:
+                continue
+        elif parts.scheme == 'file':
+            file_path = path[len('file://'):].split('::')[0]
+            try:
+                module = import_file_as_module(file_path)
+            except (FileNotFoundError, InvalidFile):
+                continue
+        else:
+            continue
+
+        for item_key in dir(module):
+            item = getattr(module, item_key)
+            try:
+                if item.__module__ != module_path:
+                    # Make sure we only clear the cache specific to the module.
+                    raise AttributeError
+
+                item.cache_clear()
+            except AttributeError:
+                pass
+
+    get_settings.cache_clear()
+
 
 class Settings:
     DEFAULT_FILTERS = {
diff --git a/tests/filters/regex_filter_test.py b/tests/filters/regex_filter_test.py
index 80f27ed52..8c0814de3 100644
--- a/tests/filters/regex_filter_test.py
+++ b/tests/filters/regex_filter_test.py
@@ -2,6 +2,7 @@
 
 from detect_secrets import filters
 from detect_secrets.core.usage import ParserBuilder
+from detect_secrets.settings import default_settings
 from detect_secrets.settings import get_settings
 
 
@@ -86,3 +87,18 @@ def test_should_exclude_secret(parser):
             ],
         },
     ]
+
+
+def test_cache_should_be_cleared_with_different_settings(parser):
+    with default_settings():
+        parser.parse_args([
+            '--exclude-lines', 'abcde',
+        ])
+
+        assert filters.regex.should_exclude_line('abcde') is True
+
+    # Since the regex isn't cached anymore, it needs to be regenerated. However,
+    # we didn't configure the regex in the settings object, so it will raise a KeyError
+    # when trying to obtain the patterns.
+    with pytest.raises(KeyError):
+        assert filters.regex.should_exclude_line('abcde')