Automate with: find Tests -type f -print0 | xargs -0 perl -i -0pe \ 's/set\(([a-zA-Z0-9_]+)(\s+)"\$\{\1\}([^"])/string(APPEND \1\2"\3/g'
Add a RunCMake.if test to cover if() command behavior. Start with a test for IS_DIRECTORY cases with an existing directory and a long path, both with a trailing slash.