markdownlint

markdownlint documentation

Version in Mega-Linter: 0.29.0
Visit Official Web Site
See How to configure markdownlint rules
- If custom .markdown-lint.json config file is not found, .markdown-lint.json will be used
See How to disable markdownlint rules in files
See Index of problems detected by markdownlint

Configuration in Mega-Linter

Enable markdownlint by adding MARKDOWN_MARKDOWNLINT in ENABLE_LINTERS variable
Disable markdownlint by adding MARKDOWN_MARKDOWNLINT in DISABLE_LINTERS variable

Enable auto-fixes by adding MARKDOWN_MARKDOWNLINT in APPLY_FIXES variable

Variable	Description	Default value
MARKDOWN_DEFAULT_STYLE	For markdownlint to be active, MARKDOWN_DEFAULT_STYLE must be `markdownlint`	`markdownlint`
MARKDOWN_MARKDOWNLINT_ARGUMENTS	User custom arguments to add in linter CLI call Ex: `-s --foo "bar"`
MARKDOWN_MARKDOWNLINT_FILTER_REGEX_INCLUDE	Custom regex including filter Ex: `(src\\|lib)`	Include every file
MARKDOWN_MARKDOWNLINT_FILTER_REGEX_EXCLUDE	Custom regex excluding filter Ex: `(test\\|examples)`	Exclude no file
MARKDOWN_MARKDOWNLINT_CLI_LINT_MODE	Override default CLI lint mode - `file`: Calls the linter for each file - `list_of_files`: Call the linter with the list of files as argument - `project`: Call the linter from the root of the project	`{linter.cli_lint_mode}`
MARKDOWN_MARKDOWNLINT_FILE_EXTENSIONS	Allowed file extensions. `"*"` matches any extension, `""` matches empty extension. Empty list excludes all files Ex: `[".py", ""]`	`[".md"]`
MARKDOWN_MARKDOWNLINT_FILE_NAMES_REGEX	File name regex filters. Regular expression list for filtering files by their base names using regex full match. Empty list includes all files Ex: `["Dockerfile(-.+)?", "Jenkinsfile"]`	Include every file
MARKDOWN_MARKDOWNLINT_PRE_COMMANDS	List of bash commands to run before the linter	None
MARKDOWN_MARKDOWNLINT_POST_COMMANDS	List of bash commands to run after the linter	None
MARKDOWN_MARKDOWNLINT_CONFIG_FILE	markdownlint configuration file name Use `LINTER_DEFAULT` to let the linter find it	`.markdown-lint.json`
MARKDOWN_MARKDOWNLINT_RULES_PATH	Path where to find linter configuration file	Workspace folder, then Mega-Linter default rules
MARKDOWN_MARKDOWNLINT_DISABLE_ERRORS	Run linter but consider errors as warnings	`true`
MARKDOWN_MARKDOWNLINT_DISABLE_ERRORS_IF_LESS_THAN	Maximum number of errors allowed	`0`

IDE Integration

Use markdownlint in your favorite IDE to catch errors before Mega-Linter !

IDE	Extension Name	Install
Atom	linter-node-markdownlint	Visit Web Site
Sublime Text	SublimeLinter-contrib-markdownlint	Visit Web Site
vim	coc-markdownlint	Visit Web Site
Visual Studio Code	vscode-markdownlint

Mega-Linter Flavours

This linter is available in the following flavours

Flavor	Description	Embedded linters
all	Default Mega-Linter Flavor	94
dart	Optimized for DART based projects	41
documentation	Mega-Linter for documentation projects	40
dotnet	Optimized for C, C++, C# or VB based projects	47
go	Optimized for GO based projects	42
java	Optimized for JAVA based projects	42
javascript	Optimized for JAVASCRIPT or TYPESCRIPT based projects	49
php	Optimized for PHP based projects	44
python	Optimized for PYTHON based projects	49
ruby	Optimized for RUBY based projects	41
rust	Optimized for RUST based projects	41
salesforce	Optimized for Salesforce based projects	43
scala	Optimized for SCALA based projects	41
swift	Optimized for SWIFT based projects	41
terraform	Optimized for TERRAFORM based projects	45

Behind the scenes

How are identified applicable files

File extensions: .md

How the linting is performed

markdownlint is called once with the list of files as arguments

Example calls

markdownlint myfile.md

markdownlint -c .markdown-lint.json myfile.md

markdownlint --fix -c .markdown-lint.json myfile.md

Help content

Usage: markdownlint [options] <files|directories|globs>

MarkdownLint Command Line Interface

Options:
  -V, --version                               output the version number
  -c, --config [configFile]                   configuration file (JSON, JSONC, JS, or YAML)
  -d, --dot                                   include files/folders with a dot (for example `.github`)
  -f, --fix                                   fix basic errors (does not work with STDIN)
  -i, --ignore [file|directory|glob]          file(s) to ignore/exclude (default: [])
  -j, --json                                  write issues in json format
  -o, --output [outputFile]                   write issues to file (no console)
  -p, --ignore-path [file]                    path to file with ignore pattern(s)
  -r, --rules  [file|directory|glob|package]  custom rule files (default: [])
  -s, --stdin                                 read from STDIN (does not work with files)
  -h, --help                                  display help for command

Installation on mega-linter Docker image

NPM packages (node.js):
- markdownlint-cli

Example success log

Results of markdownlint linter (version 0.25.0)
See documentation on https://nvuillam.github.io/mega-linter/descriptors/markdown_markdownlint/
-----------------------------------------------

[SUCCESS] .automation/test/markdown/markdown_good_1.md

Example error log

Results of markdownlint linter (version 0.25.0)
See documentation on https://nvuillam.github.io/mega-linter/descriptors/markdown_markdownlint/
-----------------------------------------------

[ERROR] .automation/test/markdown/markdown_bad_1.md
    .automation/test/markdown/markdown_bad_1.md:1 MD041/first-line-heading/first-line-h1 First line in file should be a top level heading [Context: "## Bad Markdown"]
    .automation/test/markdown/markdown_bad_1.md:5 MD001/heading-increment/header-increment Heading levels should only increment by one level at a time [Expected: h3; Actual: h6]
    .automation/test/markdown/markdown_bad_1.md:11:1 MD007/ul-indent Unordered list indentation [Expected: 4; Actual: 6]
    .automation/test/markdown/markdown_bad_1.md:13 MD040/fenced-code-language Fenced code blocks should have a language specified [Context: "```"]
    .automation/test/markdown/markdown_bad_1.md:20:16 MD034/no-bare-urls Bare URL used [Context: "https://github.com"]