unified engine to create a command line interface from a unified processor.

• What is this?
• When should I use this?
• Install
• Use
• API
  • args(options)
  • Options
• CLI
  • Files
  • --color
  • --config
  • --ext <extensions>
  • --file-path <path>
  • --frail
  • --help
  • --ignore
  • --ignore-path <path>
  • --ignore-path-resolve-from cwd|dir
  • --ignore-pattern <globs>
  • --inspect
  • --output [path]
  • --quiet
  • --rc-path <path>
  • --report <reporter>
  • --setting <settings>
  • --silent
  • --silently-ignore
  • --stdout
  • --tree
  • --tree-in
  • --tree-out
  • --use <plugin>
  • --verbose
  • --version
  • --watch
• Diagnostics
• Debugging
• Types
• Compatibility
• Security
• Contribute
• License

This package wraps unified-engine so that it can be used to create a command line interface. It’s what you use underneath when you use remark-cli.

You can use this to let users process multiple files from the command line, letting them configure from the file system.

This package is ESM only. In Node.js (version 16+), install with npm:

npm install unified-args

The following example creates a CLI for remark, which will search for files in folders with a markdown extension, allows configuration from .remarkrc and package.json files, ignoring files from .remarkignore files, and more.

Say our module example.js looks as follows:

import {remark} from 'remark'
import {args} from 'unified-args'

args({
  description:
    'Command line interface to inspect and change markdown files with remark',
  extensions: [
    'md',
    'markdown',
    'mdown',
    'mkdn',
    'mkd',
    'mdwn',
    'mkdown',
    'ron'
  ],
  ignoreName: '.remarkignore',
  name: 'remark',
  packageField: 'remarkConfig',
  pluginPrefix: 'remark',
  processor: remark,
  rcName: '.remarkrc',
  version: '11.0.0'
})

…now running node example.js --help yields:

Usage: remark [options] [path | glob ...]

  Command line interface to inspect and change markdown files 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
  …

This package exports the identifier args. There is no default export.

Start the CLI.

👉 Note: this takes over the entire process. It parses process.argv, exits when its done, etc.

• options (Options, required) — configuration

Nothing (undefined).

Configuration (TypeScript type).

• description (string, required) — description of executable
• extensions (Array<string>, required) — default file extensions to include (engine: options.extensions)
• ignoreName (string, required) — name of ignore files to load (engine: options.ignoreName)
• name (string, required) — name of executable
• packageField (string, required) — field where configuration can be found in package.jsons (engine: options.packageField)
• pluginPrefix (string, required) — prefix to use when searching for plugins (engine: options.pluginPrefix)
• processor (Processor, required) — processor to use (engine: options.processor)
• rcName (string, required) — name of configuration files to load (engine: options.rcName)
• version (string, required) — version of executable

CLIs created with unified-args, such as the example above, have an interface similar to the below:

Usage: remark [options] [path | glob ...]

  Command line interface to inspect and change markdown files 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

All non-options passed to the cli are seen as input and can be:

• paths (readme.txt) and globs (*.txt) pointing to files to load
• paths (test) and globs (fixtures/{in,out}/) pointing to folders, which are searched for files with known extensions which are not ignored by patterns in ignore files. The default behavior is to exclude files in node_modules/ unless explicitly given

You can force things to be seen as input by using --:

cli -- globs/* and/files

• default: none
• engine: options.files

cli --no-color input.txt

Whether to output ANSI color codes in the report.

• default: whether the terminal supports color
• engine: options.color

👉 Note: This option may not work depending on the reporter given in --report.

cli --no-config input.txt

Whether to load configuration files.

Searches for files with the configured rcName: $rcName and $rcName.json (JSON), $rcName.yml and $rcName.yaml (YAML), $rcName.js (JavaScript), $rcName.cjs (CommonJS), and $rcName.mjs (ESM); and looks for the configured packageField in package.json files.

• default: on
• engine: options.detectConfig

cli --ext html .
cli --ext htm --ext html .
cli --ext htm,html .

Specify one or more extensions to include when searching for files.

• default: configured extensions
• alias: -e
• engine: options.extensions

cli --file-path input.txt < input.txt > doc/output.txt

File path to process the given file on stdin(4) as, if any.

• default: none
• engine: options.filePath

cli --frail input.txt

Exit with a status code of 1 if warnings or errors occur. The default behavior is to exit with 1 on errors.

• default: off
• alias: -f
• engine: options.frail

cli --help

Output short usage information.

• default: off
• alias: -h

cli --no-ignore .

Whether to load ignore files.

Searches for files named $ignoreName.

• default: on
• engine: options.detectIgnore

cli --ignore-path .gitignore .

File path to an ignore file to load, regardless of --ignore.

• default: none
• alias: -i
• engine: options.ignorePath

cli --ignore-path node_modules/my-config/my-ignore --ignore-path-resolve-from cwd .

Resolve patterns in the ignore file from its directory (dir, default) or the current working directory (cwd).

• default: 'dir'
• engine: options.ignorePathResolveFrom

cli --ignore-pattern "docs/*.md" .

Additional patterns to use to ignore files.

• default: none
• engine: options.ignorePatterns

cli --inspect < input.txt

Output the transformed syntax tree, formatted with unist-util-inspect. This does not run the compilation phase.

• default: off
• engine: options.inspect

cli --output -- .
cli --output doc .
cli --output doc/output.text input.txt

Whether to write successfully processed files, and where to. Can be set from configuration files.

• if output is not given, files are not written to the file system
• otherwise, if path is not given, files are overwritten when successful
• otherwise, if path points to a folder, files are written there
• otherwise, if one file is processed, the file is written to path

👉 Note: intermediate folders are not created.

• default: off
• alias: -o
• engine: options.output

cli --quiet input.txt

Ignore files without any messages in the report. The default behavior is to show a success message.

• default: off
• alias: -q
• engine: options.quiet

👉 Note: this option may not work depending on the reporter given in --report.

cli --rc-path config.json .

File path to a configuration file to load, regardless of --config.

• default: none
• alias: -r
• engine: options.rcPath

cli --report ./reporter.js input.txt
cli --report vfile-reporter-json input.txt
cli --report json input.txt
cli --report json=pretty:2 input.txt
cli --report 'json=pretty:"\t"' input.txt
# Only last one is used:
cli --report pretty --report json input.txt

Reporter to load by its name or path, optionally with options, and use to report metadata about every processed file.

To pass options, follow the name by an equals sign (=) and settings, which have the same in syntax as --setting <settings>.

The prefix vfile-reporter- can be omitted. Prefixed reporters are preferred over modules without prefix.

If multiple reporters are given, the last one is used.

• default: none, which uses vfile-reporter
• engine: options.reporter and options.reporterOptions

👉 Note: the quiet, silent, and color options may not work with the used reporter. If they are given, they are preferred over the same properties in reporter settings.

cli --setting alpha:true input.txt
cli --setting bravo:true --setting '"charlie": "delta"' input.txt
cli --setting echo-foxtrot:-2 input.txt
cli --setting 'golf: false, hotel-india: ["juliet", 1]' input.txt

Configuration for the parser and compiler of the processor. Can be set from configuration files.

The given settings are JSON5, with one exception: surrounding braces must not be used. Instead, use JSON syntax without braces, such as "foo": 1, "bar": "baz".

• default: none
• alias: -s
• engine: options.settings

cli --silent input.txt

Show only fatal errors in the report. Turns --quiet on.

• default: off
• alias: -S
• engine: options.silent

👉 Note: this option may not work depending on the reporter given in --report.

cli --silently-ignore **/*.md

Skip given files which are ignored by ignore files, instead of warning about them.

• default: off
• engine: options.silentlyIgnore

cli --no-stdout input.txt

Whether to write a processed file to stdout(4).

• default: off if --output or --watch are given, or if multiple files could be processed
• engine: options.out

cli --tree < input.json > output.json

Treat input as a syntax tree in JSON and output the transformed syntax tree. This runs neither the parsing nor the compilation phase.

• default: off
• alias: -t
• engine: options.tree

cli --tree-in < input.json > input.txt

Treat input as a syntax tree in JSON. This does not run the parsing phase.

• default: same as --tree
• engine: options.treeIn

cli --tree-out < input.txt > output.json

Output the transformed syntax tree. This does not run the compilation phase.

• default: same as --tree
• engine: options.treeOut

cli --use remark-man input.txt
cli --use man input.txt
cli --use 'toc=max-depth:3' input.txt
cli --use ./plugin.js input.txt

Plugin to load by its name or path, optionally with options, and use on every processed file. Can be set from configuration files.

To pass options, follow the plugin by an equals sign (=) and settings, which have the same in syntax as --setting <settings>.

Plugins prefixed with the configured pluginPrefix are preferred over modules without prefix.

• default: none
• alias: -u
• engine: options.plugins

cli --verbose input.txt

Print more info for messages.

• default: off
• engine: options.verbose

👉 Note: this option may not work depending on the reporter given in --report.

cli --version

Output version number.

• default: off
• alias: -v

cli -qwo .

Yields:

Watching... (press CTRL+C to exit)
Note: Ignoring `--output` until exit.

Process as normal, then watch found files and reprocess when they change. The watch is stopped when SIGINT is received (usually done by pressing CTRL-C).

If --output is given without path, it is not honored, to prevent an infinite loop. On operating systems other than Windows, when the watch closes, a final process runs including --output.

• default: off
• alias: -w

CLIs created with unified-args exit with:

• 1 on fatal errors
• 1 on warnings in --frail mode, 0 on warnings otherwise
• 0 on success

CLIs can be debugged by setting the DEBUG environment variable to *, such as DEBUG="*" cli example.txt.

This package is fully typed with TypeScript. It export the additional type Options.

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, unified-engine@^11, compatible with Node.js 16.

unified-args loads and evaluates configuration files, plugins, and presets from the file system (often from node_modules/). That means code that is on your file system runs. Make sure you trust the workspace where you run unified-args and be careful with packages from npm and changes made by contributors.

See contributing.md in unifiedjs/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

MIT © Titus Wormer