Nested lists are not handled properly

[z0u]

Using domador and megamark, a transform from Markdown -> HTML -> Markdown -> HTML fails to preserve nested lists.

Transform to HTML (correct):

megamark(
    "1. Item 1\n" +
    "2. Item 2\n" +
    "    1. Item 2.1\n" +
    "    2. Item 2.2\n" +
    "3. Item 3\n"
)

1. Item 1
2. Item 2
   1. Item 2.1
   2. Item 2.2
3. Item 3

Transform back to Markdown:

domador(megamark(
    "1. Item 1\n" +
    "2. Item 2\n" +
    "    1. Item 2.1\n" +
    "    2. Item 2.2\n" +
    "3. Item 3\n"
))

1. Item 1
2. Item 2
  1. Item 2.1
  2. Item 2.2
3. Item 3

Transform back to HTML (error):

megamark(domador(megamark(
    "1. Item 1\n" +
    "2. Item 2\n" +
    "    1. Item 2.1\n" +
    "    2. Item 2.2\n" +
    "3. Item 3\n"
)))

1. Item 1
2. Item 2
3. Item 2.1
4. Item 2.2
5. Item 3

I'm not sure if this is a bug in domador or megamark, but I think either:

• megamark should use two spaces to identify nested lists, like GFM, or
• domador should use four spaces to nest lists, like SO.

[z0u]

Another use case is a paragraph in a nested list:

Transform to HTML (correct):

megamark(
    "1. Foo 1\n" +
    "1. Foo 2\n" +
    "    1. Bar 1\n" +
    "\n" +
    "       Bar 1 (continued)\n" +
    "    1. Bar 2\n" +
    "1. Foo 3\n"
)

1. Foo 1
2. Foo 2

   1. Bar 1

      Bar 1 (continued)

   2. Bar 2

3. Foo 3

Transform to Markdown and HTML again (error):

megamark(domador(megamark(
    "1. Foo 1\n" +
    "1. Foo 2\n" +
    "    1. Bar 1\n" +
    "\n" +
    "       Bar 1 (continued)\n" +
    "    1. Bar 2\n" +
    "1. Foo 3\n"
)))

1. Foo 1
2. Foo 2

Bar 1

Bar 1 (continued)

1. Bar 2
2. Foo 3

[bevacqua]

Could you PR a fix for this?

[z0u]

Sadly probably not; I don't think I'll have time in this project.

[bevacqua]

@jywarren Maybe you could look into this one? 🎉

[jywarren]

I think it'll be pretty similar to #8, but I need to spend time on the issues in bevacqua/banksy#5, which are high priority for my own project.

For this, it could be similar to the nesting-in-tables code in #8, using an inUl or inList property.

[philayres]

I needed to handle this myself to cater for 3 spaces for ordered lists. I put together a quick fix, to allow a configurable number of spaces for ordered and unordered lists.

This allows megamark to nest ordered lists, where the number of padding spaces must align with the first non-space character in the parent. This change doesn't handle actual detection of the number of spaces required, but does make it work with short lists - allowing me to specify 3 spaces as an option is good enough.

I'll submit the PR, in case it is useful to anybody else.

#11