vfile

What is vfile?

The vfile npm package is a virtual file format for text processing systems, which allows for the manipulation and handling of file-related information in a structured and consistent way. It is commonly used in projects involving the processing of markdown, text, and similar content, providing a standardized interface for plugins and utilities.

What are vfile's main functionalities?

Creating and modifying virtual files

This feature allows users to create a new virtual file and modify its contents. The example demonstrates creating a vfile with initial content and then appending additional text to it.

const vfile = require('vfile');

const file = vfile({path: './example.txt', contents: 'Hello, world!'});
file.contents += ' Modified content.';
console.log(file.contents);

Accessing file metadata

This feature enables users to access metadata of the file such as the path and basename. The example shows how to create a vfile and retrieve its path and basename properties.

const vfile = require('vfile');

const file = vfile({path: './example.txt', contents: 'Hello, world!'});
console.log(file.path); // Outputs: './example.txt'
console.log(file.basename); // Outputs: 'example.txt'

Handling errors and messages

This feature is useful for adding error or warning messages to a file, which can be particularly helpful in linting tools or compilers. The example demonstrates adding an error message to a vfile and logging all associated messages.

const vfile = require('vfile');

const file = vfile();
file.message('Unknown error', {line: 1, column: 1});
console.log(file.messages);

Other packages similar to vfile

vinyl

Vinyl is a virtual file format that is often used in the gulp build system. It is similar to vfile in that it represents file objects in a virtual form, but it is more focused on being used with streams, particularly in the context of gulp's pipelines.

mem-fs

mem-fs provides an in-memory file system which stores file representations similar to vfile. While vfile is designed for text processing with a focus on linting and transformation, mem-fs is geared more towards temporary storage and manipulation of files in memory during tasks like scaffolding or testing.

README

vfile is a small and browser friendly virtual file format that tracks metadata (such as a file’s path and value) and messages.

It was made specifically for unified and generally for the common task of parsing, transforming, and serializing data, where vfile handles everything about the document being compiled. This is useful for example when building linters, compilers, static site generators, or other build tools. vfile is part of the unified collective.

• for updates, see Twitter
• for more about us, see unifiedjs.com
• for questions, see Discussions
• to help, see contribute or sponsor below

vfile is different from the excellent vinyl in that it has a smaller API, a smaller size, and focuses on messages.

Contents

• Install
• Use
• API
  • VFile(options?)
  • vfile.value
  • vfile.cwd
  • vfile.path
  • vfile.basename
  • vfile.stem
  • vfile.extname
  • vfile.dirname
  • vfile.history
  • vfile.messages
  • vfile.data
  • VFile#toString(encoding?)
  • VFile#message(reason[, position][, origin])
  • VFile#info(reason[, position][, origin])
  • VFile#fail(reason[, position][, origin])
• List of utilities
• Reporters
• Contribute
• Sponsor
• Acknowledgments
• License

Install

This package is ESM only: Node 12+ is needed to use it and it must be imported instead of required.

npm:

npm install vfile

Use

import {VFile} from 'vfile'

var file = new VFile({path: '~/example.txt', value: 'Alpha *braavo* charlie.'})

file.path // => '~/example.txt'
file.dirname // => '~'

file.extname = '.md'

file.basename // => 'example.md'

file.basename = 'index.text'

file.history // => ['~/example.txt', '~/example.md', '~/index.text']

file.message('`braavo` is misspelt; did you mean `bravo`?', {line: 1, column: 8})

console.log(file.messages)

Yields:

[
  [~/index.text:1:8: `braavo` is misspelt; did you mean `bravo`?] {
    reason: '`braavo` is misspelt; did you mean `bravo`?',
    line: 1,
    column: 8,
    source: null,
    ruleId: null,
    position: {start: [Object], end: [Object]},
    file: '~/index.text',
    fatal: false
  }
]

API

This package exports the following identifiers: VFile. There is no default export.

VFile(options?)

Create a new virtual file. If options is string or Buffer, treats it as {value: options}. If options is a VFile, shallow copies its data over to the new file. All other given fields are set on the newly created VFile.

Path related properties are set in the following order (least specific to most specific): history, path, basename, stem, extname, dirname.

It’s not possible to set either dirname or extname without setting either history, path, basename, or stem as well.

Example

new VFile()
new VFile('console.log("alpha");')
new VFile(Buffer.from('exit 1'))
new VFile({path: path.join('path', 'to', 'readme.md')})
new VFile({stem: 'readme', extname: '.md', dirname: path.join('path', 'to')})
new VFile({other: 'properties', are: 'copied', ov: {e: 'r'}})

vfile.value

Buffer, string, null — Raw value.

vfile.cwd

string — Base of path. Defaults to process.cwd().

vfile.path

string? — Path of vfile. Cannot be nullified. You can set a file URL (a URL object with a file: protocol) which will be turned into a path with url.fileURLToPath.

vfile.basename

string? — Current name (including extension) of vfile. Cannot contain path separators. Cannot be nullified either (use file.path = file.dirname instead).

vfile.stem

string? — Name (without extension) of vfile. Cannot be nullified, and cannot contain path separators.

vfile.extname

string? — Extension (with dot) of vfile. Cannot be set if there’s no path yet and cannot contain path separators.

vfile.dirname

string? — Path to parent directory of vfile. Cannot be set if there’s no path yet.

vfile.history

Array.<string> — List of file-paths the file moved between.

vfile.messages

Array.<VMessage> — List of messages associated with the file.

vfile.data

Object — Place to store custom information. It’s OK to store custom data directly on the vfile, moving it to data gives a little more privacy.

VFile#toString(encoding?)

Convert value of vfile to string. When value is a Buffer, encoding is a character encoding to understand it as (string, default: 'utf8').

VFile#message(reason[, position][, origin])

Associates a message with the file, where fatal is set to false. Constructs a new VMessage and adds it to vfile.messages.

Returns

VMessage.

VFile#info(reason[, position][, origin])

Associates an informational message with the file, where fatal is set to null. Calls #message() internally.

Returns

VMessage.

VFile#fail(reason[, position][, origin])

Associates a fatal message with the file, then immediately throws it. Note: fatal errors mean a file is no longer processable. Calls #message() internally.

Throws

VMessage.

List of utilities

The following list of projects includes tools for working with virtual files. See unist for projects that work with nodes.

• convert-vinyl-to-vfile — transform from Vinyl to vfile
• to-vfile — create a vfile from a filepath
• vfile-find-down — find files by searching the file system downwards
• vfile-find-up — find files by searching the file system upwards
• vfile-glob — find files by glob patterns
• vfile-is — check if a vfile passes a test
• vfile-location — convert between positional and offset locations
• vfile-matter — parse the YAML front matter
• vfile-message — create a vfile message
• vfile-messages-to-vscode-diagnostics — transform vfile messages to VS Code diagnostics
• vfile-mkdirp — make sure the directory of a vfile exists on the file system
• vfile-rename — rename the path parts of a vfile
• vfile-sort — sort messages by line/column
• vfile-statistics — count messages per category: failures, warnings, etc
• vfile-to-eslint — convert to ESLint formatter compatible output

Reporters

The following list of projects show linting results for given virtual files. Reporters must accept Array.<VFile> as their first argument, and return string. Reporters may accept other values too, in which case it’s suggested to stick to vfile-reporters interface.

• vfile-reporter — create a report
• vfile-reporter-json — create a JSON report
• vfile-reporter-folder-json — create a JSON representation of vfiles
• vfile-reporter-pretty — create a pretty report
• vfile-reporter-junit — create a jUnit report
• vfile-reporter-position — create a report with content excerpts

Contribute

See contributing.md in vfile/.github for ways to get started. See support.md for ways to get help. Ideas for new utilities and tools can be posted in vfile/ideas.

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

Sponsor

Support this effort and give back by sponsoring on OpenCollective!

Gatsby 🥇	Vercel 🥇	Netlify	Holloway	ThemeIsle	Boost Hub	Expo
You?

Acknowledgments

The initial release of this project was authored by @wooorm.

Thanks to @contra, @phated, and others for their work on Vinyl, which was a huge inspiration.

Thanks to @brendo, @shinnn, @KyleAMathews, @sindresorhus, and @denysdovhan for contributing commits since!

License

MIT © Titus Wormer