How to all #nullable disable to all files in solution

Question

I want to migrate my codebase to nullable references. One of migration strategies consists of adding #nullable disable prefix to all files. How I can do it automatically?

Answer 1

One way is to:

1. Go to "Replace in Files"
2. Check "Use regular expressions"
3. Set the "Find" box to ^(?<![\n])
4. Set the "Replace" box to #nullable disable\n
5. Set the "File types" to at least contain *.cs
6. Test carefully! I like to do a "Find All" first to make sure the matches are what I want, and use a backup/version control.

^(?<![\n]) is a regex which matches the start of a line (^) which isn't preceeded by a newline ((?<![\n])). In other words, the start of the first line of a file.