configure markdownlint-cli2 to lint math in CLI and pre-commit hook properly

.markdownlint-cli2.jsonc

{
  "markdownItPlugins": [
    ["markdown-it-texmath"]
  ],
  "config": {
    "MD013": false
  }
}

.pre-commit-config.yaml

# See https://pre-commit.com for more information
# See https://pre-commit.com/hooks.html for more hooks
repos:
  - repo: https://github.com/DavidAnson/markdownlint-cli2
    rev: v0.5.1
    hooks:
      - id: markdownlint-cli2
        additional_dependencies: ["markdown-it-texmath", "katex"]

README.md

Proper linting of math documents using markdownlint-cli2

The problem is that when linting example.md, a false positive MD049 warning is generated.

$ markdownlint-cli2 example.md
markdownlint-cli2 v0.5.1 (markdownlint v0.26.2)
Finding: example.md
Linting: 1 file(s)
Summary: 1 error(s)
example.md:6:6 MD049/emphasis-style Emphasis style should be consistent [Expected: asterisk; Actual: underscore]

Solution

Use markdown-it-texmath plugin so that math syntax is parsed correctly.

1. Install plugin and dependencies

   npm install markdown-it-texmath katex

   For usage with a pre-commit hook, these need to be added as additional_dependencies:

   - repos:
     - repo: https://github.com/DavidAnson/markdownlint-cli2
       hooks:
         - id: markdownlint-cli2
           additional_dependencies: ["markdown-it-texmath", "katex"]

2. Reference plugin in markdownlint-cli2 configuration file (e.g. .markdownlint-cli2.jsonc):

   {
     "markdownItPlugins": [
       ["markdown-it-texmath"]
     ]
   }

example.md

Heading

Text with some emphasis

$$ q^{'}{i} = q^{'}{i+1} $$