inconsistent indenting of nested lists

[afeld]

Describe the bug

context
When I run MdFormat on this notebook through nbqa…

expectation
I expected to get nested lists indented a certain number of spaces.

bug
But instead some are indented two spaces, while some are indented three.

diff --git hw_0.ipynb hw_0.ipynb
index 4aaa010..ef99e82 100644
--- hw_0.ipynb
+++ hw_0.ipynb
@@ -11,16 +11,16 @@
     "Kaggle, like JupyterHub and Google Colab, is built around Jupyter notebooks. They are not _exactly_ the same, but will feel similar. For this homework
:\n",
     "\n",
     "1. Do following Kaggle [Learn Python](https://www.kaggle.com/learn/python) tutorials and exercises. You do not need to turn these in.\n",
-    "    - [Hello, Python](https://www.kaggle.com/colinmorris/hello-python)\n",
-    "    - [Booleans and Conditionals](https://www.kaggle.com/colinmorris/booleans-and-conditionals)\n",
-    "    - [Strings and Dictionaries](https://www.kaggle.com/colinmorris/strings-and-dictionaries)\n",
+    "   - [Hello, Python](https://www.kaggle.com/colinmorris/hello-python)\n",
+    "   - [Booleans and Conditionals](https://www.kaggle.com/colinmorris/booleans-and-conditionals)\n",
+    "   - [Strings and Dictionaries](https://www.kaggle.com/colinmorris/strings-and-dictionaries)\n",
     "1. Read about:\n",
-    "    - [Tuples, lists, and dictionaries](http://sthurlow.com/python/lesson06/)\n",
-    "    - [Errors and exceptions](https://swcarpentry.github.io/python-novice-inflammation/09-errors/index.html)\n",
+    "   - [Tuples, lists, and dictionaries](http://sthurlow.com/python/lesson06/)\n",
+    "   - [Errors and exceptions](https://swcarpentry.github.io/python-novice-inflammation/09-errors/index.html)\n",
     "1. Do the coding challenges below.\n",
     "1. Do the following Kaggle tutorials and exercises. You do not need to turn these in.\n",
-    "    - [Python Lists](https://www.kaggle.com/colinmorris/lists)\n",
-    "    - [Creating, Reading, and Writing with Pandas](https://www.kaggle.com/residentmario/creating-reading-and-writing)\n",
+    "   - [Python Lists](https://www.kaggle.com/colinmorris/lists)\n",
+    "   - [Creating, Reading, and Writing with Pandas](https://www.kaggle.com/residentmario/creating-reading-and-writing)\n",
     "1. Post a question, per the instructions at the bottom.\n",
     "1. [Turn in this notebook.](https://python-public-policy.afeld.me/en/latest/README.html#turning-in-assignments)\n",
     "\n",
@@ -163,8 +163,8 @@
     "We will now make an interactive tool to assess people for unemployment benefits. We will use a simplified version of [the rules from the New York Stat
e Department of Labor](https://www.labor.ny.gov/formsdocs/ui/TC318.3e.pdf#page=18), as follows. To be elegible, one must:\n",
     "\n",
     "- Have lost employment\n",
-    "- Have made at least $10,000 in the past year\n",
-    "    - Ask for their salary rather than as a yes-or-no question\n",
+    "- Have made at least \\$10,000 in the past year\n",
+    "  - Ask for their salary rather than as a yes-or-no question\n",
     "- Be ready, willing and able to work immediately\n",
     "- Be actively seeking work\n",
     "\n",

problem
This is a problem because I'm publishing that notebook via JupyterBook, and it's Markdown parser only seems to support nested lists indented 3+ spaces.

cc #331 (comment) for the option to make that configurable for more fragile Markdown parsers

Reproduce the bug

1. Download this notebook

2. Run Mdformat through nbqa:

   nbqa mdformat hw_0.ipynb --nbqa-md

List your environment

$ jupyter-book --version
Jupyter Book      : 0.13.1
External ToC      : 0.2.4
MyST-Parser       : 0.15.2
MyST-NB           : 0.13.2
Sphinx Book Theme : 0.3.3
Jupyter-Cache     : 0.4.3
NbClient          : 0.5.13
$ nbqa --version
nbqa 1.5.3
$ mdformat --version
mdformat 0.7.16 (mdformat_myst: 0.1.5, mdformat_tables: 0.4.1, mdformat_frontmatter: 0.4.1)

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[hukkin]

But instead some are indented two spaces, while some are indented three.

The logic here is as follows:

• mdformat always indents unordered lists with two spaces
• indent width of ordered lists depends on the width of the initial number of the ordered list

  1. Here indent width is
     three.
  
  123. Here indent width is
       five. It needs to be so, because
  
       Otherwise this next paragraph doesn't belong in the same list item.

This is a problem because I'm publishing that notebook via JupyterBook, and it's Markdown parser only seems to support nested lists indented 3+ spaces.

Hmm, are you 100% sure about this? I'm doubtful, because JupyterBook uses myst-nb which uses myst-parser which uses markdown-it-py to parse Markdown, and that is a CommonMark compliant parser which happens to be the same exact parser used by mdformat.

[KyleKing]

I published mdformat-mkdocs to format list indents to 4-spaces, which might be helpful for your use case

[hukkin]

This is a problem because I'm publishing that notebook via JupyterBook, and it's Markdown parser only seems to support nested lists indented 3+ spaces.

Closing, as this issue should be fixed now by installing KyleKing's mdformat-mkdocs plugin.