.gitignore and .eleventyignore don’t support negative patterns

[veleek]

Describe the bug
.eleventyignore files that use negative ignore patterns return unexpected results because eleventy modifies the paths a bit.

To Reproduce
Steps to reproduce the behavior:

1. Create an eleventy ignore file with a regular pattern and a negative pattern

   site/**/*
   !site/events/2018/**
   

2. Run eleventy ignore
3. Note that no files are copied

Expected behavior
Negative patterns should allow you to re-include ignored paths

Environment:

• OS and Version: Windows
• Eleventy Version: 0.9.0

Additional context
Eleventy modifies the patterns in the ignore file by prefixing a relative path header (./) and then adding the ! to the beginning. As a result, the example above (!site/events/2018/**) gets turned into !./!site/events/2018/** when being passed to fast-glob. Fast glob processes negative patterns separately so it pulls that pattern out and removes the ! and actually strips the ./ before using it, so it ends up using !site/events/2018/** as the negative pattern and this basically says ignore anything that's not a match for site/events/2018. Since site/events is not a match for this, the whole folder gets excluded and fast-glob never scans any deeper for files that SHOULD be included.

I haven't had a chance to try it out yet, but this problem could potentially be solve by not modifying the patterns in .eleventyignore and using the new ignore parameter to fast-glob which handles the negation for you. I haven't looked too closely at what modifications eleventy does to see if they're necessary for some of the output processing so hopefully it's just not necessary.

Note: This is a new issue related to the upgrade to fast-glob 3.X. Definitely prefer to use the new version, but would love to have it continue to use .eleventyignore the same way I was before.

[coolsoftwaretyler]

Edit

Maybe not a duplicate, but related to #677?

[veleek]

Yeah. Pretty much a duplicate. If you don't have an .eleventyignore file it will use the gitignore by default. But that explains why my searches for existing bugs didn't find anything.

[zachleat]

Placing this into the enhancement queue. #677 is a related issue to this but not quite the same.

As info, v0.10.0 will include a debug warning if it encounters one of these entries.

[alberto]

I was hit by this. My use case is I use Sass so I want to .gitignore the CSS files output directory. But I still want eleventy to process them. I tried using a negative pattern in .eleventyignore to include them but it didn't work.

In case it helps, eslint does something similar with .gitignore and .eslintignore and it uses https://github.com/kaelzhang/node-ignore to achieve this behaviour.

For others landing here, I worked around it by setting eleventyConfig.setUseGitIgnore(false); and duplicating my ignored files in .eleventyignore, except the CSS directory, obviously.

[zachleat]

A note for future me:

Two dependencies require some level of support here: chokidar and fast-glob

In 1.0 we’ll use fast-glob’s ignore option instead of negated globs. We were already using chokidar’s ignored option here.

These will both need to be tested to know if negated patterns are supported in the ignore/ignored options.

[zachleat]

Related #3680, #3442

[zachleat]

Cross link to https://www.npmjs.com/package/parse-gitignore or https://www.npmjs.com/package/@humanwhocodes/gitignore-to-minimatch or https://www.npmjs.com/package/ignore