I'm writing my custom rule for eslint and I'm trying to add a custom message at the top of the file (with --fix) if not already present. My fix function is:

fix: fixer => fixer.insertTextBefore(sourceCode.ast, licenseInComments)

where

sourceCode = context.getSourceCode();

However, ast returns the whole program node excluding any comment present at the beginning of the file. I want my message to be above even the fist comment. Any ideas how I could do that?