Link labels cannot be empty

[tomByrer]

empty Link Labels should not be parsed

via CommonMark, but should be logical regardless:

A link label begins with a left bracket ([) and ends with the first right
bracket (]) that is not backslash-escaped. Between these brackets there must
be at least one non-whitespace character.

Steps to reproduce

const fs = require('fs')
const remark = require("remark")
const inspect = require('unist-util-inspect')

const tree = remark().parse(`[ ] brackets with white space inside`)
console.log(inspect(tree))

$ node view-ast.js
root[1] (1:1-1:37, 0-36)
└─ paragraph[2] (1:1-1:37, 0-36)
   ├─ linkReference[1] (1:1-1:4, 0-3) [identifier=" "][label=" "][referenceType="shortcut"]
   │  └─ text: " " (1:2-1:3, 1-2)
   └─ text: " brackets with white space inside" (1:4-1:37, 3-36)

More through test; seems GFM Task List is OK with ignoring the Linked List:
https://astexplorer.net/#/gist/51df6d1a522d5a08c3017d92549345f9/ac9ddaca577f5115e7e220c74acbe786ab3a4a11

Expected behaviour

$ node view-ast.js
root[1] (1:1-1:37, 0-36)
└─ paragraph[2] (1:1-1:37, 0-36)
   └─ text: "[ ] brackets with white space inside" (1:1-1:37, 3-36)

cheers, & thanks for all your hard work!

[wooorm]

Thanks for the issue! This is indeed a bug, but we are working on an alternative to the internals of remark here: #439

[tomByrer]

Thanks for your reply.

Yes, I saw micromark, but seems it won't be ready for another 6+ months as a 'new internals', & this is bug might be a blocker for me.

Either way, another test case to add to the pile.

[wooorm]

Heya, just wanted to give an update about micromark, it’s sort-of a new motor that we’ll soon use in remark to parse markdown. It’s not yet 100% ready but will be relatively soon. The good news is, it fixes this issue! (P.S. see this twitter thread for some more info!)

[wooorm]

Sorry for the wait! I just wanted to share that there’s now a PR that solves this issue: #536.

[wooorm]

This is now released in remark@13.0.0