Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and discussions and couldn’t find anything or linked relevant results below
• I made sure the docs are up to date
• I included tests (or that’s not needed)

Description of changes

as we discuss about "negative lookbehind" not working on old version safari in this issue: #10
I try to update it:

1. fix windows issue while runing on fresh test
2. add a check if current system support:

function transformGfmAutolinkLiterals(tree) {
  if (regexSupport.lookbehind) {
    modernAutolinkTransform(tree)
  } else {
    legacyAutolinkTransform(tree)
  }
}

the test is simple and running before we do anything else:

// Regex support detector
const regexSupport = {
  lookbehind: (() => {
    try {
      // Using regex literal instead of RegExp constructor
      ;/(?<=x)/.test('x')
      return true
    } catch {
      return false
    }
  })()
}

the result is fine:

The before change test:

The after change test:

I also try to install nodejs 16 but it not work, so I realize I cannot use many new syntax since nodejs 16 not support. Then I understand why you want to skip support.

I also try to build, to replace my current code to test on my ios, but the node_modules not found the autolink-literal since it is very deep link. I will try to test futher on ios 16.

I hope you can give me some thought about my idea. I don't mind if it useless and should not be merge, since I'm not have many experience. I would like to here what you think.

Thank you <3