Regex Editor & Tester

Matches the two arguments of an Assert.Equal(expected, actual) call in C# unit tests, using \K to reset the match start so only the arguments themselves are captured. The recursive subpattern (?1) combined with the (?(R)...) conditional handles balanced parentheses, allowing commas inside nested calls like Assert.Equal(Foo(a, b), Bar(c)) to be parsed correctly. Useful for refactoring tools, argument-swapping linters, or highlighting assert expressions in code search.