Code inspection: Merge 'and' pattern

This inspection reports an and pattern whose operands can be merged into a simpler single pattern. In the tested cases, this happens when one side of the and already narrows the type and the other side adds a compatible pattern condition.

Example

                if (o is A and ("", 0))
                {
                }
            

                if (o is A("", 0))
                {
                }
            

Quick-fix

Merge the compatible parts of the and pattern into one pattern.

30 March 2026