Empty first line breaks the header plugin

[donmahallem]

Currently if the first line is emtpy in the source file and the header starts at line 2 the fixer causes the header to be output many(non consistent but 10+ times) times in succession.

[Nokel81]

I have made #50 to resolve this issue.

[lizozom]

For anyone interested in this, adding the @stylistic/js/no-multiple-empty-lines rule with maxBOF: 0 before this one fixes the issue.

[lizozom]

Community PR:
Outburn-IL/fume-community#43

[tonyganchev]

It seems the repo has not been maintained for ~3 years. Last year I had to fork https://github.com/tonyganchev/eslint-plugin-header to publish fixes for ESLint 9, Windows, and general issues. I am willing to look into the problem and accept this contribution.

There are two issues here:

1. Empty lines before the header are not skipped during validation - I've filed Handle empty lines before a header tonyganchev/eslint-plugin-header#61 to track design work as the default behavior leads to more consistency in the codebase.
2. Because of (1), ESLint would attempt an autofix - with the current behavior of the plugin, the "missing header" will be appended not at the beginning of the file but before the first meaningful parsing token. Since the empty lines remain in the beginning of the source, linting would still fail after the autofix and ESLint would reattempt autofixing up to 8 times before it gives up. This is how you end up with multiple comments. The good news is that fix: header is added immediately after shebang - fixes #14 tonyganchev/eslint-plugin-header#17 addressed this issue by always adding the comment at the top or right after the shebang. The fix is in production with v3.1.6 of the forked plugin.