fix(regex): honour leading inline flags like (?i) on .NET Regex#3305
Merged
dgozman merged 1 commit intomicrosoft:mainfrom May 1, 2026
Merged
fix(regex): honour leading inline flags like (?i) on .NET Regex#3305dgozman merged 1 commit intomicrosoft:mainfrom
dgozman merged 1 commit intomicrosoft:mainfrom
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Strips a leading inline flag group `(?ism-ism)` from the regex source before sending to the driver, and merges those flags with `Regex.Options`. The pattern is otherwise sent verbatim and JS-side regex syntax does not support `(?i)` modifier groups, so they previously failed with "Invalid group". Fixes microsoft#3236
pavelfeldman
approved these changes
May 1, 2026
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Summary
Regex.ToString()returns the pattern verbatim (including any leading inline modifier like(?i)), butRegex.Optionsonly carries the constructor flags. So a pattern likenew Regex(\"(?i).+\\.css$\")was sent to the JS-side matcher with noiflag and a(?i)group that JS regex syntax rejects.Regex.GetSourceAndFlags()helper strips a leading(?ism-ism)modifier group and merges the enabled/disabled bits into the wire flags. All 7 sites that previously sent(regex.ToString(), regex.Options.GetInlineFlags())now use it (route handlers, web-socket route handler,AssertionsBase,Locatorselector escaping,BrowserContext.ClearCookiesAsync/HarStart,EvaluateArgumentValueConverter).n,x) throwArgumentException, matching the existing behavior for unsupportedRegexOptions.Fixes #3236