Inserted <p> into <li> on different unordered lists

[ybiquitous]

Describe the bug

When putting different two unordered lists (- and *) with blank lines, a <p> tag is inserted into <li> tag.

E.g.

- a1
- a2

* b1
* b2

To Reproduce

1. Marked Demo
2. CommonMark Demo

On terminal:

1. Install marked: npm install --save marked@0.6.2
2. Run marked:

$ cat <<EOF | ./node_modules/.bin/marked
- a1
- a2

* b1
* b2
EOF

3. Actual output (or error) is:

<ul>
<li><p>a1</p>
</li>
<li><p>a2</p>
</li>
<li><p>b1</p>
</li>
<li><p>b2</p>
</li>
</ul>

Expected behavior

Like CommonMark, I think marked should output the following HTML:

<ul>
<li>a1</li>
<li>a2</li>
</ul>
<ul>
<li>b1</li>
<li>b2</li>
</ul>

[UziTech]

Adding an extra new line will make it render correctly but this is a bug.

[ybiquitous]

I think so, too. 👍

[ansuz]

I played around with the parser and saw a suspicious looking line.

The patch below seems to fix this issue:

22c22
<   list: /^( *)(bull) [\s\S]+?(?:hr|def|\n{1,}(?! )(?!\1bull )\n*|\s*$)/,
---
>   list: /^( *)(bull) [\s\S]+?(?:hr|def|\n{2,}(?! )(?!\1bull )\n*|\s*$)/,

...but I don't know that it doesn't cause other problems which are potentially much worse.

If anyone can point me towards any tests I should run I can turn this into a PR pretty quickly.

[UziTech]

Running npm test from your marked directory will run the tests.

Alternatively, if you submit a PR the tests will automatically run on travis-ci

[ansuz]

As my PR says, the fix causes all sorts of failures. If the PR isn't acceptable hopefully it at least serves as a good starting point for an investigation into the problem.

[UziTech]

I don't think that is the right fix. It seems like the right fix should change the regex to distinguish between - and *

[ansuz]

@UziTech: as per your comment on my PR:

according to the original markdown spec:

If list items are separated by blank lines, Markdown will wrap the items in <p> tags in the HTML output.

This seems to be intended behaviour, which I guess invalidates your above comment:

Adding an extra new line will make it render correctly but this is a bug.

If that's the case, I suppose this issue should be marked as wontfix and closed?

[UziTech]

The original issue uses two different list item styles (- and *) which should render as two separate lists with a single blank line between them. Your test only uses a single list item style (*) which, as my comment states, should render a single loose list.

[github-actions]

🎉 This issue has been resolved in version 1.2.3 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[yannicklescure]

Hi, I'm using version "4.0.15" along with NodeJS. The bug is still present (or is back).
Edit: I'm fixing the issue by using this dirty code

const markdown = marked.parse(data).replaceAll('</p>\n</li>', '</li>').replaceAll('<li><p>', '<li>');

[calculuschild]

@yannicklescure Can you give us an example input and output showing yhe problem? We can add it to our test suite and reopen this issue.

[yannicklescure]

@calculuschild I did further test trying to narrow the issue. Here is what I have tried.

- a1
- a2

* b1
* b2

1. c1
2. c2

* d1

* d2

* e1

* e2

1. f1

2. f2

- g1

The serie a, b, c gives the expected result i.e.: <li>a1</li>
The serie d, e, f gives the list of elements adding p inside li. Notice the added space between the lines. i.e.: <li><p>a1</p></li>
g1 works fine.

[UziTech]

That is called a loose list and that is intended behavior that follows the CommonMark spec.

[yannicklescure]

@UziTech Thank you, I learn something new.