fix: use non-capturing group for highlight boundaries (#5784)

CHANGELOG.md

@@ -10,6 +10,7 @@
 - Bugfix: Fixed a crash that could occur on Linux and macOS when clicking "Install" from the update prompt. (#5818)
 - Bugfix: Fixed missing word wrap in update popup. (#5811)
 - Bugfix: Fixed tabs not scaling to the default scale when changing the scale from a non-default value. (#5794)
+- Dev: Highlight checks now use non-capturing groups for the boundaries. (#5784)
 - Dev: Updated Conan dependencies. (#5776)
 
 ## 2.5.2

src/controllers/highlights/HighlightPhrase.cpp

@@ -1,11 +1,13 @@
 #include "controllers/highlights/HighlightPhrase.hpp"
 
+#include <QStringBuilder>
+
 namespace chatterino {
 
 namespace {
 
-    const QString REGEX_START_BOUNDARY("(\\b|\\s|^)");
-    const QString REGEX_END_BOUNDARY("(\\b|\\s|$)");
+    constexpr QStringView REGEX_START_BOUNDARY(u"(?:\\b|\\s|^)");
+    constexpr QStringView REGEX_END_BOUNDARY(u"(?:\\b|\\s|$)");
 
 }  // namespace
 
@@ -46,7 +48,7 @@ HighlightPhrase::HighlightPhrase(const QString &pattern, bool showInMentions,
     , soundUrl_(soundUrl)
     , regex_(isRegex_
                  ? pattern
-                 : REGEX_START_BOUNDARY + QRegularExpression::escape(pattern) +
+                 : REGEX_START_BOUNDARY % QRegularExpression::escape(pattern) %
                        REGEX_END_BOUNDARY,
              QRegularExpression::UseUnicodePropertiesOption |
                  (isCaseSensitive_ ? QRegularExpression::NoPatternOption
@@ -69,7 +71,7 @@ HighlightPhrase::HighlightPhrase(const QString &pattern, bool showInMentions,
     , color_(std::move(color))
     , regex_(isRegex_
                  ? pattern
-                 : REGEX_START_BOUNDARY + QRegularExpression::escape(pattern) +
+                 : REGEX_START_BOUNDARY % QRegularExpression::escape(pattern) %
                        REGEX_END_BOUNDARY,
              QRegularExpression::UseUnicodePropertiesOption |
                  (isCaseSensitive_ ? QRegularExpression::NoPatternOption