Command line interface to inspect and change markdown files with remark.
Contents
What is this?
This package is a command line interface (CLI) that you can use in your terminal or in npm scripts and the like to inspect and change markdown files. This CLI is built around remark, which is an ecosystem of plugins that work with markdown as structured data, specifically ASTs (abstract syntax trees). You can choose from the 150+ existing plugins or make your own.
See the monorepo readme for info on what the remark ecosystem is.
When should I use this?
You can use this package when you want to work with the markdown files in your project from the command line. remark-cli has many options and you can combine it with many plugins, so it should be possible to do what you want. If not, you can always use remark itself manually in a script.
Install
This package is ESM only. In Node.js (version 16+), install with npm:
npm install remark-cli
Use
Add a table of contents with remark-toc to readme.md:
remark readme.md --output --use remark-toc
Lint all markdown files in the current directory according to the markdown style guide with remark-preset-lint-markdown-style-guide.
remark . --use remark-preset-lint-markdown-style-guide
CLI
The interface of remark-cli is explained as follows on its help page (remark --help):
Usage: remark [options] [path | glob ...]
CLI to process markdown with remark
Options:
--[no-]color specify color in report (on by default)
--[no-]config search for configuration files (on by default)
-e --ext <extensions> specify extensions
--file-path <path> specify path to process as
-f --frail exit with 1 on warnings
-h --help output usage information
--[no-]ignore search for ignore files (on by default)
-i --ignore-path <path> specify ignore file
--ignore-path-resolve-from cwd|dir resolve patterns in `ignore-path` from its directory or cwd
--ignore-pattern <globs> specify ignore patterns
--inspect output formatted syntax tree
-o --output [path] specify output location
-q --quiet output only warnings and errors
-r --rc-path <path> specify configuration file
--report <reporter> specify reporter
-s --setting <settings> specify settings
-S --silent output only errors
--silently-ignore do not fail when given ignored files
--[no-]stdout specify writing to stdout (on by default)
-t --tree specify input and output as syntax tree
--tree-in specify input as syntax tree
--tree-out output syntax tree
-u --use <plugins> use plugins
--verbose report extra info for messages
-v --version output version number
-w --watch watch for changes and reprocess
Examples:
# Process `input.md`
$ remark input.md -o output.md
# Pipe
$ remark < input.md > output.md
# Rewrite all applicable files
$ remark . -o
More info on all these options is available at unified-args, which does the work. remark-cli is unified-args preconfigured to:
Examples
This example checks and formats markdown with remark-cli. It assumes you’re in a Node.js package.
Install the CLI and plugins:
npm install remark-cli remark-preset-lint-consistent remark-preset-lint-recommended remark-toc --save-dev
…then add an npm script in your package.json:
/* … */
"scripts": {
/* … */
"format": "remark . --output",
/* … */
},
/* … */
💡 Tip: add ESLint and such in the format script too.
The above change adds a format script, which can be run with npm run format. It runs remark on all markdown files (.) and rewrites them (--output). Run ./node_modules/.bin/remark --help for more info on the CLI.
Then, add a remarkConfig to your package.json to configure remark:
/* … */
"remarkConfig": {
"settings": {
"bullet": "*", // Use `*` for list item bullets (default)
// See <https://github.com/remarkjs/remark/tree/main/packages/remark-stringify> for more options.
},
"plugins": [
"remark-preset-lint-consistent", // Check that markdown is consistent.
"remark-preset-lint-recommended", // Few recommended rules.
[
// Generate a table of contents in `## Contents`
"remark-toc",
{
"heading": "contents"
}
]
]
},
/* … */
👉 Note: you must remove the comments in the above examples when copy/pasting them as comments are not supported in package.json files.
Finally, you can run the npm script to check and format markdown files in your project:
npm run format
Example: config files (JSON, YAML, JS)
In the previous example, we saw that remark-cli was configured from within a package.json file. That’s a good place when the configuration is relatively short, when you have a package.json, and when you don’t need comments (which are not allowed in JSON).
You can also define configuration in separate files in different languages. With the package.json config as inspiration, here’s a JavaScript version that can be placed in .remarkrc.js:
import remarkPresetLintConsistent from 'remark-preset-lint-consistent'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import remarkToc from 'remark-toc'
const remarkConfig = {
settings: {
bullet: '*', // Use `*` for list item bullets (default)
// See <https://github.com/remarkjs/remark/tree/main/packages/remark-stringify> for more options.
},
plugins: [
remarkPresetLintConsistent, // Check that markdown is consistent.
remarkPresetLintRecommended, // Few recommended rules.
// Generate a table of contents in `## Contents`
[remarkToc, {heading: 'contents'}]
]
}
export default remarkConfig
This is the same configuration in YAML, which can be placed in .remarkrc.yml:
settings:
bullet: "*"
plugins:
# Check that markdown is consistent.
- remark-preset-lint-consistent
# Few recommended rules.
- remark-preset-lint-recommended
# Generate a table of contents in `## Contents`
- - remark-toc
- heading: contents
When remark-cli is about to process a markdown file it’ll search the file system upwards for configuration files starting at the folder where that file exists. Take the following file structure as an illustration:
folder/
├─ subfolder/
│ ├─ .remarkrc.json
│ └─ file.md
├─ .remarkrc.js
├─ package.json
└─ readme.md
When folder/subfolder/file.md is processed, the closest config file is folder/subfolder/.remarkrc.json. For folder/readme.md, it’s folder/.remarkrc.js.
The order of precedence is as follows. Earlier wins (so in the above file structure folder/.remarkrc.js wins over folder/package.json):
.remarkrc (JSON).remarkrc.cjs (CJS).remarkrc.js (CJS or ESM, depending on type: 'module' in package.json).remarkrc.json (JSON).remarkrc.mjs (ESM).remarkrc.yaml (YAML).remarkrc.yml (YAML)package.json with remarkConfig field
Compatibility
Projects maintained by the unified collective are compatible with maintained versions of Node.js.
When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, remark-cli@^12, compatible with Node.js 16.
Security
As markdown can be turned into HTML and improper use of HTML can open you up to cross-site scripting (XSS) attacks, use of remark can be unsafe. When going to HTML, you will likely combine remark with rehype, in which case you should use rehype-sanitize.
Use of remark plugins could also open you up to other attacks. Carefully assess each plugin and the risks involved in using them.
For info on how to submit a report, see our security policy.
Contribute
See contributing.md in remarkjs/.github for ways to get started. See support.md for ways to get help. Join us in Discussions to chat with the community and contributors.
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License
MIT © Titus Wormer