unified-engine
Advanced tools
unified engine to process multiple files, lettings users configure from the file system
The unified-engine is a powerful tool for processing text using plugins. It is part of the unified collective, which is a project that provides a suite of tools for working with content as structured data. The engine allows you to read, process, and write files using a pipeline of plugins, making it highly extensible and customizable.
Reading Files
This feature allows you to read files from the filesystem. In this example, the engine reads a Markdown file using the 'remark-parse' plugin.
const engine = require('unified-engine');
const vfile = require('to-vfile');
engine({
files: ['example.md'],
processor: unified().use(require('remark-parse')),
cwd: process.cwd(),
extensions: ['md'],
output: false
}, (err, status) => {
if (err) throw err;
console.log('Files read successfully');
});Processing Files
This feature allows you to process files using a pipeline of plugins. In this example, the engine processes a Markdown file and converts it to HTML using 'remark-parse' and 'remark-html' plugins.
const engine = require('unified-engine');
const unified = require('unified');
const markdown = require('remark-parse');
const html = require('remark-html');
engine({
files: ['example.md'],
processor: unified().use(markdown).use(html),
cwd: process.cwd(),
extensions: ['md'],
output: 'example.html'
}, (err, status) => {
if (err) throw err;
console.log('Files processed successfully');
});Writing Files
This feature allows you to write processed files back to the filesystem. In this example, the engine writes the processed HTML output to 'example.html'.
const engine = require('unified-engine');
const vfile = require('to-vfile');
const unified = require('unified');
const markdown = require('remark-parse');
const html = require('remark-html');
engine({
files: ['example.md'],
processor: unified().use(markdown).use(html),
cwd: process.cwd(),
extensions: ['md'],
output: 'example.html'
}, (err, status) => {
if (err) throw err;
console.log('Files written successfully');
});Gulp is a toolkit for automating painful or time-consuming tasks in your development workflow. It uses a code-over-configuration approach and is highly extensible with plugins. Compared to unified-engine, Gulp is more general-purpose and can handle a wider range of tasks beyond text processing.
Webpack is a module bundler primarily for JavaScript, but it can transform front-end assets like HTML, CSS, and images if the corresponding loaders are used. While unified-engine focuses on processing text files using plugins, Webpack is more about bundling and optimizing assets for web applications.
Broccoli is a fast, reliable asset pipeline, supporting constant-time rebuilds and compact build definitions. It is similar to Gulp but focuses more on the build pipeline for front-end assets. Compared to unified-engine, Broccoli is more specialized in asset management and build processes.
unified engine to process multiple files, lettings users configure from the file system.
options.alwaysStringifyoptions.configTransformoptions.defaultConfigoptions.detectConfigoptions.detectIgnoreoptions.extensionsoptions.filePathoptions.filesoptions.frailoptions.ignoreNameoptions.ignorePathoptions.ignorePathResolveFromoptions.ignorePatternsoptions.ignoreUnconfiguredoptions.inspectoptions.outoptions.outputoptions.packageFieldoptions.pluginPrefixoptions.pluginsoptions.processoroptions.quietoptions.rcNameoptions.rcPathoptions.reporter and options.reporterOptionsoptions.settingsoptions.silentoptions.streamErroroptions.streamInoptions.streamOutoptions.treeoptions.treeInoptions.treeOutThis package is the engine.
It’s what you use underneath when you use remark-cli or a
language server.
Compared to unified, this deals with multiple files, often from the file
system, and with configuration files and
ignore files.
You typically use something that wraps this, such as:
unified-args
— create CLIsunified-engine-gulp
— create Gulp pluginsunified-language-server
— create language serversYou can use this to make such things.
This package is ESM only. In Node.js (version 16+), install with npm:
npm install unified-engine
The following example processes all files in the current folder with a
markdown extension with remark, allows configuration
from .remarkrc and package.json files, ignoring files from .remarkignore
files, and more.
/**
* @typedef {import('unified-engine').Callback} Callback
*/
import process from 'node:process'
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
color: true,
extensions: ['md', 'markdown', 'mkd', 'mkdn', 'mkdown'],
files: ['.'],
ignoreName: '.remarkignore',
packageField: 'remarkConfig',
pluginPrefix: 'remark',
processor: remark,
rcName: '.remarkrc'
},
done
)
/** @type {Callback} */
function done(error, code) {
if (error) throw error
process.exitCode = code
}
This package exports the identifiers Configuration and
engine.
There is no default export.
engine(options, callback)Process.
Nothing (undefined).
ConfigurationInternal class to load configuration files.
Exposed to build more complex integrations.
options (subset of Options, required)
— configuration (cwd is required)load(string, (Error?[, Result?]): undefined): undefined
— get the config for a fileCompleterCompleter (TypeScript type).
type Completer = (CompleterCallback | CompleterRegular) & {
pluginId?: string | symbol | undefined
}
type CompleterCallback = (set: FileSet, next: CompleterCallbackNext) => undefined
type CompleterCallbackNext = (error?: Error | null | undefined) => undefined
type CompleterRegular = (set: FileSet) => Promise<undefined> | undefined
CallbackCallback called when done (TypeScript type).
Called with a fatal error if things went horribly wrong (probably due to incorrect configuration), or a status code and the processing context.
error (Error, optional)
— errorcode (0 or 1, optional)
— exit code, 0 if successful or 1 if unsuccessfulcontext (Context, optional)
— processing contextNothing (undefined).
ConfigTransformTransform arbitrary configs to our format (TypeScript type).
config (unknown)
— arbitrary configfilePath (string)
— file path of config fileOur config format (Preset).
ContextProcessing context (TypeScript type).
fileSet (FileSet)
— internally used infofiles (Array<VFile>)
— processed filesFileSetA FileSet is created to process multiple files through unified processors (TypeScript type).
This set, containing all files, is exposed to plugins as the second parameter.
None.
valueOf(): Array<VFile>
— get files in a setuse(completer: Completer): this
— add middleware to be called when done (see: Completer)add(file: VFile | string): this
— add a file; the given file is processed like other files with a few
differences: it’s ignored when their file path is already added, never
written to the file system or streamOut, and not included in the reportOptionsConfiguration (TypeScript type).
👉 Note:
options.processoris required.
alwaysStringify (boolean, default: false)
— whether to always serialize successfully processed filescolor (boolean, default: false)
— whether to report with ANSI color sequences; given to the reporterconfigTransform (ConfigTransform, optional)
— transform config files from a different schemacwd (URL or string, default: process.cwd())
— folder to search files in, load plugins from, and moredefaultConfig (Preset, optional)
— default configuration to use if no config file is given or founddetectConfig (boolean, default: true if options.packageField or
options.rcName)
— whether to search for configuration filesdetectIgnore (boolean, default: true if options.ignoreName)
— whether to search for ignore filesextensions (Array<string>, optional)
— search for files with these extensions, when folders are passed;
generated files are also given the first extension if treeIn is on and
output is on or points to a folderfilePath (URL or string, optional)
— file path to process the given file on streamIn asfiles (Array<URL | VFile | string>, optional)
— paths or globs to files and folder, or virtual files, to
processfrail (boolean, default: false)
— call back with an unsuccessful (1) code on warnings as well as errorsignoreName (string, optional)
— name of ignore files to loadignorePath (URL or string, optional)
— filepath to an ignore file to loadignorePathResolveFrom (ResolveFrom, default:
'dir')
— resolve patterns in ignorePath from the current working folder
('cwd') or the ignore file’s folder ('dir')ignorePatterns (optional)
— patterns to ignore in addition to ignore filesignoreUnconfigured (boolean, default: false)
— ignore files that do not have an associated detected configuration file;
either rcName or packageField must be defined too; cannot be combined
with rcPath or detectConfig: falseinspect (boolean, default: false)
— whether to output a formatted syntax tree for debuggingout (boolean, default: false)
— whether to write the processed file to streamOutoutput (URL, boolean or string, default: false)
— whether to write successfully processed files, and where to; when true,
overwrites the given files, when false, does not write to the file system;
when pointing to an existing folder, files are written to that folder and
keep their original basenames; when the parent folder of the given path
exists and one file is processed, the file is written to the given pathpackageField (string, optional)
— field where configuration can be found in package.json filespluginPrefix (string, optional)
— prefix to use when searching for pluginsplugins (Preset['plugins'], optional)
— plugins to useprocessor (Processor, required)
— unified processor to transform filesquiet (boolean, default: false)
— do not report successful files; given to the reporterrcName (string, optional)
— name of configuration files to loadrcPath (URL or string, optional)
— filepath to a configuration file to loadreporter (VFileReporter or string, default:
vfile-reporter)
— reporter to use; if a string is passed, it’s loaded from cwd, and
'vfile-reporter-' can be omittedreporterOptions (Options from
vfile-reporter, optional)
— config to pass to the used reportersettings (Settings from unified, optional)
— configuration for the parser and compiler of the processorsilent (boolean, default: false)
— report only fatal errors; given to the reportersilentlyIgnore (boolean, default: false)
— skip given files if they are ignoredstreamError (WritableStream from Node.js,
default: process.stderr)
— stream to write the report (if any) tostreamIn (ReadableStream from Node.js,
default: process.stdin)
— stream to read from if no files are found or givenstreamOut (WritableStream from Node.js,
default: process.stdout)
— stream to write processed files to, nothing is streamed if either out
is false, output is not false, multiple files are processed, or a
fatal error occurred while processing a filetree (boolean, default: false)
— whether to treat both input and output as a syntax treetreeIn (boolean, default: options.tree)
— whether to treat input as a syntax treetreeOut (boolean, default: options.tree)
— whether to output as a syntax treePresetSharable configuration, with support for specifiers (TypeScript type).
Specifiers should not be used in actual presets (because they can’t be used by regular unified), but they can be used in config files locally, as those are only for the engine.
They can contain plugins and settings.
import type {
Plugin as UnifiedPlugin,
PluginTuple as UnifiedPluginTuple,
Preset as UnifiedPreset,
Settings
} from 'unified'
type Preset = {
plugins?: PluggableList | PluggableMap | undefined
settings?: Settings | undefined
}
type Pluggable = Plugin | PluginTuple | UnifiedPreset
type PluggableList = Array<Pluggable>
type PluggableMap = Record<string, unknown>
type Plugin = UnifiedPlugin | string
type PluginTupleSupportingSpecifiers =
| [plugin: string, ...parameters: Array<unknown>]
| UnifiedPluginTuple
ResolveFromHow to resolve (TypeScript type).
type ResolveFrom = 'cwd' | 'dir';
VFileReporterTransform arbitrary configs to our format (TypeScript type).
This is essentially the interface of vfile-reporter, with
added support for unknown fields in options and async support.
files (Array<VFile>)
— filesoptions (Options from vfile-reporter,
optional)
— configurationReport (Promise<string> or string).
unified-engine accepts configuration through options and through
configuration files (rc files).
One configuration file can be given through options.rcPath, this is loaded
regardless of options.detectConfig and options.rcName.
Otherwise, configuration files are detected if options.detectConfig is turned
on, depending on the following options:
options.rcName is given, $rcName (JSON), $rcName.js (CommonJS or
ESM depending on the type field of the closest package.json),
$rcName.cjs (CommonJS), $rcName.mjs (ESM), $rcName.yml (YAML),
and $rcName.yaml (YAML) are loadedoptions.packageField is given, package.json (JSON) files are loaded
and the configuration at their $packageField field is usedThe first file that is searched for in a folder is used as the configuration. If no file is found, the parent folder is searched, and so on.
The schema (type) of rc files is Preset.
An example rc file could look as follows:
{
"plugins": [
"remark-inline-links",
"remark-lint-recommended"
],
"settings": {
"bullet": "*",
"ruleRepetition": 3,
"fences": true
}
}
Another example, rc.js, could look as follows:
exports.plugins = [
'./script/natural-language.js',
'remark-lint-recommended',
'remark-license'
]
exports.settings = {bullet: '*'}
When using ESM (ECMAScript modules), rc.mjs could look as folows:
export default {
plugins: [
'./script/natural-language.js',
'remark-lint-recommended',
'remark-license'
],
settings: {bullet: '*'}
}
Another example, rc.yaml, could look as follows:
plugins:
- 'rehype-document'
- 'rehype-preset-minify'
settings:
preferUnquoted: true
quote: "'"
quoteSmart: true
verbose: true
unified-engine accepts patterns to ignore when searching for files to process
through ignore files.
One ignore file can be given through options.ignorePath, this is loaded
regardless of options.detectIgnore and options.ignoreName.
Otherwise, ignore files are detected if options.detectIgnore is turned on and
options.ignoreName is given.
The first file named $ignoreName in the parent folder of a checked file is
used.
Or, if no file is found, the parent folder if searched, and so on.
In addition to explicit and implicit ignore files, other patterns can be given
with options.ignorePatterns.
The format of each pattern in ignorePatterns is the same as a line in an
ignore file.
Patterns and files are resolved based on the current working folder.
It is also possible to ignore files that do not have an associated detected
configuration file by turning on options.ignoreUnconfigured.
Ignoring is used when searching for files in folders.
If paths (including those expanded from globs) are passed in that
are ignored, an error is thrown.
These files can be silently ignored by turning on options.silentlyIgnore.
Normally, files are ignored based on the path of the found ignore file and the
patterns inside it.
Patterns passed with options.ignorePatterns are resolved based on the current
working directory.
Patterns in an explicit ignore file passed in with options.ignorePath can be
resolved from the current working directory instead, by setting
options.ignorePathResolveFrom to 'cwd' instead of 'dir' (default).
If paths or globs to folders are given to the engine, they will be searched
for matching files, but node_modules are normally not searched.
Pass paths (or globs) to the node_modules you want to include in
options.files to search them.
The format for ignore files is the same as .gitignore, so it’s
possible to pass a .gitignore in as options.ignorePath.
node-ignore is used under the hood, see its documentation
for more information.
An example ignore file could look as follows:
# Ignore files in `.github`.
.github/
# Bower.
bower_components/
# Duo dependencies.
components/
# Fixtures.
test/{input,tree}/
If we had an ignore file folder/.remarkignore, with the value: index.txt,
and our file system looked as follows:
folder/.remarkignore
folder/index.txt
index.txt
Then folder/index.txt would be ignored but index.txt would not be.
Normally, unified plugins receive a single options argument upon attaching
(an Object users can provide to configure the plugin).
If a plugin is attached by unified-engine, a second argument is given:
FileSet.
unified-engine can be configured extensively by engine authors.
options.alwaysStringifyThis example shows how you can use options.alwaysStringify when you don’t
want the engine to write to the file system, but still want to get the compiled
results.
One example that does this is unified-engine-gulp.
import {remark} from 'remark'
import {engine} from 'unified-engine'
import {VFile} from 'vfile'
const file = new VFile({path: 'example.md', value: '_hi_'})
engine(
{alwaysStringify: true, files: [file], processor: remark},
function (error, code, context) {
if (error) throw error
console.log(context?.files.map((d) => String(d)))
}
)
Yields:
example.md: no issues found
[ '*hi*\n' ]
options.configTransformTo support custom rc files, that have a different format than what the engine
supports, pass as ConfigTransform.
This example processes readme.md and loads options from custom (from a
package.json).
configTransform is called with those options and transforms it to
configuration unified-engine understands.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
configTransform,
files: ['readme.md'],
packageField: 'custom',
processor: remark()
},
function (error) {
if (error) throw error
}
)
function configTransform(config) {
return {settings: (config || {}).options}
}
Where package.json contains:
{
"name": "foo",
"private": true,
"custom": {
"options": {
"bullet": "+"
}
}
}
options.defaultConfigThis example processes readme.md.
If package.json exists, that config is used, otherwise the configuration at
defaultConfig is used.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
defaultConfig: {settings: {bullet: '+'}},
files: ['readme.md'],
packageField: 'remarkConfig',
processor: remark()
},
function (error) {
if (error) throw error
}
)
Where package.json contains:
{
"name": "foo",
"private": true,
"remarkConfig": {
"settings": {
"bullet": "-"
}
}
}
options.detectConfigThis example processes readme.md but does not allow configuration from
.remarkrc or package.json files, as detectConfig is false.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
detectConfig: false,
files: ['readme.md'],
processor: remark(),
packageField: 'remarkConfig',
rcName: '.remarkrc'
},
function (error) {
if (error) throw error
}
)
options.detectIgnoreThis example processes files in the current working directory with an md
extension but does not ignore file paths from the closest .remarkignore
file, because detectIgnore is false.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
detectIgnore: false,
extensions: ['md'],
files: ['.'],
ignoreName: '.remarkignore',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.extensionsThis example reformats all files with md, markdown, and mkd
extensions in the current folder.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md', 'mkd', 'markdown'],
files: ['.'],
output: true,
processor: remark
},
function (error) {
if (error) throw error
}
)
options.filePathThis example shows that streamIn is named as filePath:
import {PassThrough} from 'node:stream'
import {remark} from 'remark'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import {engine} from 'unified-engine'
const streamIn = new PassThrough()
streamIn.write('doc')
setImmediate(function () {
streamIn.end('ument')
})
engine(
{
filePath: '~/alpha/bravo/charlie.md',
out: false,
plugins: [remarkPresetLintRecommended],
processor: remark(),
streamIn
},
function (error) {
if (error) throw error
}
)
Yields:
~/alpha/bravo/charlie.md
1:1 warning Missing newline character at end of file final-newline remark-lint
⚠ 1 warning
options.filesThis example processes LICENSE and all files with an md extension in doc.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['LICENSE', 'doc/'],
processor: remark
},
function (error) {
if (error) throw error
}
)
options.frailThis example uses remark-lint to lint readme.md and exits
with the given exit code.
Normally, only errors turn the code to 1, but in frail mode lint warnings
result in the same.
import process from 'node:process'
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
frail: true,
plugins: ['remark-preset-lint-recommended'],
processor: remark()
},
function (error, code) {
process.exitCode = error ? 1 : code
}
)
options.ignoreNameThis example processes files in the current working directory with an md
extension, and is configured to ignore file paths from the closest
.remarkignore file.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['.'],
ignoreName: '.remarkignore',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.ignorePathThis example processes files in the current working directory with an md
extension and ignores file paths specified in .gitignore.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['.'],
ignorePath: '.gitignore',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.ignorePathResolveFromThis example processes files in the current working directory with an md
extension and takes a reusable configuration file from a dependency.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['.'],
ignorePath: 'node_modules/my-config/my-ignore',
ignorePathResolveFrom: 'cwd',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.ignorePatternsThis example processes files in the current working directory with an md
extension, except for readme.md:
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['.'],
ignorePatterns: ['readme.md'],
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.ignoreUnconfiguredThis example processes files in the current working directory with an
md extension, but only if there is an explicit .remarkrc config file near
(upwards) to them:
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['.'],
ignoreUnconfigured: true,
processor: remark(),
rcName: '.remarkrc'
},
function (error) {
if (error) throw error
}
)
options.inspectThis example shows a module which reads and parses doc.md, then
remark-unlink transforms the syntax tree, the tree is
formatted with unist-util-inspect, and finally written
to stdout(4).
import {remark} from 'remark'
import remarkUnlink from 'remark-unlink'
import {engine} from 'unified-engine'
engine(
{
files: ['doc.md'],
inspect: true,
plugins: [remarkUnlink],
processor: remark()
},
function (error) {
if (error) throw error
}
)
Where doc.md looks as follows:
[foo](https://example.com)
Yields:
root[1] (1:1-2:1, 0-27)
└─ paragraph[1] (1:1-1:27, 0-26)
└─ text: "foo" (1:2-1:5, 1-4)
options.outThis example uses remark-lint to lint readme.md, writes the
report, and ignores the serialized document.
import {remark} from 'remark'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
out: false,
plugins: [remarkPresetLintRecommended],
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.outputThis example writes all files in src/ with an md extension compiled to
dest/.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
extensions: ['md'],
files: ['src/'],
output: 'dest/',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.packageFieldThis example processes readme.md, and allows configuration from
remarkConfig fields in package.json files.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
packageField: 'remarkConfig',
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.pluginPrefixThis example processes readme.md and loads the
preset-lint-recommended plugin.
Because pluginPrefix is given, this resolves to
remark-preset-lint-recommended (from
node_modules/) if available.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
pluginPrefix: 'remark',
plugins: ['preset-lint-recommended'],
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.pluginsThis example processes readme.md and loads the
remark-preset-lint-recommended
preset.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
plugins: ['remark-preset-lint-recommended'],
processor: remark()
},
function (error) {
if (error) throw error
}
)
options.processorThis example reformats stdin(4) using remark, writes the report to stderr(4), and formatted document to stdout(4).
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine({processor: remark}, function (error) {
if (error) throw error
})
options.quietThis example uses remark-lint to lint readme.md.
Nothing is reported if the file processed successfully.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
plugins: ['remark-preset-lint-recommended'],
processor: remark(),
quiet: true
},
function (error) {
if (error) throw error
}
)
options.rcNameThis example processes readme.md and allows configuration from .remarkrc,
.remarkrc.json, .remarkrc.yml, .remarkrc.yaml, .remarkrc.js,
.remarkrc.cjs, and .remarkrc.mjs files.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{files: ['readme.md'], processor: remark(), rcName: '.remarkrc'},
function (error) {
if (error) throw error
}
)
options.rcPathThis example processes readme.md and loads configuration from config.json.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{files: ['readme.md'], processor: remark(), rcPath: 'config.json'},
function (error) {
if (error) throw error
}
)
options.reporter and options.reporterOptionsThis example processes all HTML files in the current folder with rehype,
configures the processor with .rehyperc files, and prints a report in
JSON using vfile-reporter-json with
reporter options.
import {rehype} from 'rehype'
import {engine} from 'unified-engine'
engine(
{
extensions: ['html'],
files: ['.'],
processor: rehype(),
rcName: '.rehyperc',
reporter: 'json',
reporterOptions: {pretty: true}
},
function (error) {
if (error) throw error
}
)
options.settingsThis example processes readme.md and configures the compiler
(remark-stringify) with bullet: '+'.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{files: ['readme.md'], processor: remark(), settings: {bullet: '+'}},
function (error) {
if (error) throw error
}
)
options.silentThis example uses remark-lint to lint readme.md but does not
report any warnings or success messages, only fatal errors, if they occur.
import {remark} from 'remark'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
plugins: ['remark-preset-lint-recommended'],
processor: remark(),
silent: true
},
function (error) {
if (error) throw error
}
)
options.streamErrorThis example uses remark-lint to lint readme.md and writes
the report to report.txt.
import fs from 'node:fs'
import {remark} from 'remark'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import {engine} from 'unified-engine'
engine(
{
files: ['readme.md'],
out: false,
plugins: [remarkPresetLintRecommended],
processor: remark(),
streamErr: fs.createWriteStream('report.txt')
},
function (error) {
if (error) throw error
}
)
options.streamInThis example uses remark-lint to lint an incoming
stream.
import {PassThrough} from 'node:stream'
import {remark} from 'remark'
import remarkPresetLintRecommended from 'remark-preset-lint-recommended'
import {engine} from 'unified-engine'
const streamIn = new PassThrough()
streamIn.write('doc')
setImmediate(function () {
streamIn.end('ument')
})
engine(
{
out: false,
plugins: [remarkPresetLintRecommended],
processor: remark(),
streamIn
},
function (error) {
if (error) throw error
}
)
Yields:
<stdin>
1:1 warning Missing newline character at end of file final-newline remark-lint
⚠ 1 warning
options.streamOutThis example reads readme.md and writes the serialized document to
readme-two.md.
This can also be achieved by passing output: 'readme-two.md' instead of
streamOut.
import fs from 'node:fs'
import {remark} from 'remark'
import {engine} from 'unified-engine'
const streamOut = fs.createWriteStream('readme-two.md')
engine(
{files: ['readme.md'], processor: remark(), streamOut},
function (error) {
if (error) throw error
}
)
options.treeThis example reads tree.json, then remark-unlink
transforms the syntax tree, and the transformed tree is written to
stdout(4).
import {remark} from 'remark'
import remarkUnlink from 'remark-unlink'
import {engine} from 'unified-engine'
engine(
{
files: ['tree.json'],
plugins: [remarkUnlink],
processor: remark(),
tree: true
},
function (error) {
if (error) throw error
}
)
Where tree.json looks as follows:
{
"type": "paragraph",
"children": [{
"type": "link",
"url": "https://example.com",
"children": [{
"type": "text",
"value": "foo"
}]
}]
}
Yields:
{
"type": "paragraph",
"children": [{
"type": "text",
"value": "foo"
}]
}
options.treeInThis example reads tree.json, then remark-unlink
transforms the syntax tree, the tree is serialized, and the resulting document
is written to stdout(4).
import {remark} from 'remark'
import remarkUnlink from 'remark-unlink'
import {engine} from 'unified-engine'
engine(
{
files: ['tree.json'],
plugins: [remarkUnlink],
processor: remark(),
treeIn: true
},
function (error) {
if (error) throw error
}
)
Where tree.json looks as follows:
{
"type": "paragraph",
"children": [{
"type": "link",
"url": "https://example.com",
"children": [{
"type": "text",
"value": "foo"
}]
}]
}
Yields:
foo
options.treeOutThis example shows a module which reads and parses doc.md, then
remark-unlink transforms the syntax tree, and the tree is
written to stdout(4).
import {remark} from 'remark'
import remarkUnlink from 'remark-unlink'
import {engine} from 'unified-engine'
engine(
{
files: ['doc.md'],
plugins: [remarkUnlink],
processor: remark(),
treeOut: true
},
function (error) {
if (error) throw error
}
)
Where doc.md looks as follows:
[foo](https://example.com)
Yields:
{
"type": "paragraph",
"children": [{
"type": "text",
"value": "foo"
}]
}
This package is fully typed with TypeScript.
It exports the additional types
Completer,
Callback,
ConfigTransform,
Context,
FileSet,
Options,
Preset,
ResolveFrom, and
VFileReporter.
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-engine 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-engine 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.
FAQs
unified engine to process multiple files, lettings users configure from the file system
The npm package unified-engine receives a total of 300,609 weekly downloads. As such, unified-engine popularity was classified as popular.
We found that unified-engine demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 2 open source maintainers collaborating on the project.
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