From 1fd0c5cb4d9ed5d9f06f953a168c2d027b563e8a Mon Sep 17 00:00:00 2001
From: Rhys Arkins <rhys@arkins.net>
Date: Tue, 12 Dec 2023 09:48:22 +0100
Subject: [PATCH] refactor: increase regex validation debugging (#26244)

---
 lib/config/validation.ts | 7 ++++++-
 lib/util/regex.ts        | 4 +++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/config/validation.ts b/lib/config/validation.ts
index 7e928b23b66b5e..d83a0694cedf68 100644
--- a/lib/config/validation.ts
+++ b/lib/config/validation.ts
@@ -1,4 +1,5 @@
 import is from '@sindresorhus/is';
+import { logger } from '../logger';
 import { allManagersList, getManagerList } from '../modules/manager';
 import { isCustomManager } from '../modules/manager/custom';
 import type {
@@ -667,7 +668,11 @@ function validateRegexManagerFields(
     for (const matchString of customManager.matchStrings) {
       try {
         regEx(matchString);
-      } catch (e) {
+      } catch (err) {
+        logger.debug(
+          { err },
+          'customManager.matchStrings regEx validation error',
+        );
         errors.push({
           topic: 'Configuration Error',
           message: `Invalid regExp for ${currentPath}: \`${matchString}\``,
diff --git a/lib/util/regex.ts b/lib/util/regex.ts
index 64630d0f3cf671..60289ad1ee8643 100644
--- a/lib/util/regex.ts
+++ b/lib/util/regex.ts
@@ -49,9 +49,11 @@ export function regEx(
     }
     return instance;
   } catch (err) {
+    logger.trace({ err }, 'RegEx constructor error');
     const error = new Error(CONFIG_VALIDATION);
+    error.validationMessage = err.message;
     error.validationSource = pattern.toString();
-    error.validationError = `Invalid regular expression: ${pattern.toString()}`;
+    error.validationError = `Invalid regular expression (re2): ${pattern.toString()}`;
     throw error;
   }
 }