Version 1.0.0

@stackline/vfile

Virtual file format for text processing

Independent maintenance of vfile 5.3.7. Original authors and licenses are retained.

Installation

# Preserve existing imports with an npm alias
npm install vfile@npm:@stackline/vfile@1.0.0
# Or use the scoped package name in your imports
npm install @stackline/vfile@1.0.0

Node.js: See compatibility notes. Read the compatibility and maintenance notes before migrating.

Usage and API

The reference below may retain upstream package names. Use the alias installation above to run those imports with this Stackline release.

@stackline/vfile

Independent maintenance fork of vfile@5.3.7, preserving its API and published type declarations.

npm install @stackline/vfile
# Keep existing imports:
npm install vfile@npm:@stackline/vfile@1.0.0

Stackline · Issues · Community

See UPSTREAM.md for source identity and issue review, and CHANGELOG.md for maintenance changes. Functional tests also run against the final npm tarball; releases are published from GitHub Actions with provenance.

Upstream documentation

vfile is a small and browser friendly virtual file format that tracks metadata about files (such as its path and value) and lint messages.

unified

vfile is part of the unified collective.

for more about us, see unifiedjs.com
for how the collective is governed, see unifiedjs/collective
for updates, see @unifiedjs on Twitter

What is this?

This package provides a virtual file format. It exposes an API to access the file value, path, metadata about the file, and specifically supports attaching lint messages and errors to certain places in these files.

When should I use this?

The virtual file format is useful when dealing with the concept of files in places where you might not be able to access the file system. The message API is particularly useful when making things that check files (as in, linting).

vfile is made for unified, which amongst other things checks files. However, vfile can be used in other projects that deal with parsing, transforming, and serializing data, to build linters, compilers, static site generators, and other build tools.

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

Install

This package is ESM only. In Node.js (version 14.14 and 16.0+), install with npm:

npm install vfile

In Deno with esm.sh:

import {VFile} from 'https://esm.sh/vfile@5'

In browsers with esm.sh:

<script type="module">
  import {VFile} from 'https://esm.sh/vfile@5?bundle'
</script>

Use

import {VFile} from 'vfile'

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

console.log(file.path) // => '~/example.txt'
console.log(file.dirname) // => '~'

file.extname = '.md'

console.log(file.basename) // => 'example.md'

file.basename = 'index.text'

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

file.message('Unexpected unknown word `braavo`, did you mean `bravo`?', {
  line: 1,
  column: 8
})

console.log(file.messages)

Yields:

[
  [~/index.text:1:8: Unexpected unknown word `braavo`, did you mean `bravo`?] {
    reason: 'Unexpected unknown word `braavo`, 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 identifier VFile. There is no default export.

`VFile(options?)`

Create a new virtual file.

options is treated as:

string or Buffer — {value: options}
URL — {path: options}
VFile — shallow copies its data over to the new file
object — all fields are shallow copied over to the new file

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

You cannot set dirname or extname without setting either history, path, basename, or stem too.

Parameters

options (Compatible, optional) — file value

Returns

New instance (VFile).

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'}})

`file.value`

Raw value (Buffer, string, null).

`file.cwd`

Base of path (string, default: process.cwd() or '/' in browsers).

`file.path`

Get or set the full path (string?, example: '~/index.min.js').

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.

`file.dirname`

Get or set the parent path (string?, example: '~').

Cannot be set if there’s no path yet.

`file.basename`

Get or set the basename (including extname) (string?, example: 'index.min.js').

Cannot contain path separators ('/' on unix, macOS, and browsers, '\' on windows). Cannot be nullified (use file.path = file.dirname instead).

`file.extname`

Get or set the extname (including dot) (string?, example: '.js').

Cannot contain path separators ('/' on unix, macOS, and browsers, '\' on windows). Cannot be set if there’s no path yet.

`file.stem`

Get or set the stem (basename w/o extname) (string?, example: 'index.min').

Cannot contain path separators ('/' on unix, macOS, and browsers, '\' on windows). Cannot be nullified.

`file.history`

List of filepaths the file moved between (Array<string>).

The first is the original path and the last is the current path.

`file.messages`

List of messages associated with the file (Array<VFileMessage>).

`file.data`

Place to store custom information (Record<string, unknown>, default: {}).

It’s OK to store custom data directly on the file but moving it to data is recommended.

`VFile#toString(encoding?)`

Serialize the file.

Parameters

encoding (BufferEncoding, default: 'utf8') — character encoding to understand value as when it’s a Buffer

Returns

Serialized file (string).

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

Create a warning message associated with the file.

Its fatal is set to false and file is set to the current file path. Its added to file.messages.

Parameters

reason (string or Error) — reason for message, uses the stack and message of the error if given
place (Node, Position, or Point, optional) — place in file where the message occurred
origin (string?, optional, example: 'my-package:my-rule' or 'my-rule') — place in code where the message originates

Returns

Message (VFileMessage).

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

Create an info message associated with the file.

Its fatal is set to null and file is set to the current file path. Its added to file.messages.

Parameters

reason (string or Error) — reason for message, uses the stack and message of the error if given
place (Node, Position, or Point, optional) — place in file where the message occurred
origin (string?, optional, example: 'my-package:my-rule' or 'my-rule') — place in code where the message originates

Returns

Message (VFileMessage).

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

Create a fatal error associated with the file.

Its fatal is set to true and file is set to the current file path. Its added to file.messages.

👉 Note: a fatal error means that a file is no longer processable.

Parameters

reason (string or Error) — reason for message, uses the stack and message of the error if given
place (Node, Position, or Point, optional) — place in file where the message occurred
origin (string?, optional, example: 'my-package:my-rule' or 'my-rule') — place in code where the message originates

Returns

Nothing (never).

Throws

Message (VFileMessage).

`BufferEncoding`

Encodings supported by the buffer class (TypeScript type).

This is a copy of the types from Node.

Type

type BufferEncoding =
  | 'ascii'
  | 'utf8'
  | 'utf-8'
  | 'utf16le'
  | 'ucs2'
  | 'ucs-2'
  | 'base64'
  | 'base64url'
  | 'latin1'
  | 'binary'
  | 'hex'

`Compatible`

Things that can be passed to the constructor (TypeScript type).

Type

type Compatible = Options | URL | Value | VFile

`Data`

Custom information (TypeScript type).

Known attributes can be added to DataMap.

Type

type Data = Record<string, unknown> & Partial<DataMap>

`DataMap`

This map registers the type of the data key of a VFile (TypeScript type).

This type can be augmented to register custom data types.

Type

interface DataMap {}

Example

declare module 'vfile' {
  interface DataMap {
    // `file.data.name` is typed as `string`
    name: string
  }
}

`Map`

Raw source map (TypeScript type).

See source-map.

Fields

version (number) — which version of the source map spec this map is following
sources (Array<string>) — an array of URLs to the original source files
names (Array<string>) — an array of identifiers which can be referenced by individual mappings
sourceRoot (string, optional) — the URL root from which all sources are relative
sourcesContent (Array<string>, optional) — an array of contents of the original source files
mappings (string) — a string of base64 VLQs which contain the actual mappings
file (string) — the generated file this source map is associated with

`Options`

An object with arbitrary fields and the following known fields (TypeScript type).

Fields

value (Value, optional) — set value
cwd (string, optional) — set cwd
history (Array<string>, optional) — set history
path (URL | string, optional) — set path
basename (string, optional) — set basename
stem (string, optional) — set stem
extname (string, optional) — set extname
dirname (string, optional) — set dirname
data (Data, optional) — set data

`Reporter`

Type for a reporter (TypeScript type).

Type

type Reporter<Settings extends ReporterSettings> = (
  files: Array<VFile>,
  options: Settings
) => string

`ReporterSettings`

Configuration for reporters (TypeScript type).

Type

type ReporterSettings = Record<string, unknown>

`Value`

Contents of the file (TypeScript type).

Can either be text or a Buffer structure.

Type

type Value = string | Buffer

Well-known

The following fields are considered “non-standard”, but they are allowed, and some utilities use them:

stored (boolean) — whether a file was saved to disk; this is used by vfile reporters
result (unknown) — custom, non-string, compiled, representation; this is used by unified to store non-string results; one example is when turning markdown into React nodes
map (Map) — source map; this type is equivalent to the RawSourceMap type from the source-map module

There are also well-known fields on messages, see them in a similar section of vfile-message.

List of utilities

convert-vinyl-to-vfile — transform from Vinyl
to-vfile — create a file from a filepath and read and write to the file system
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 file passes a test
vfile-location — convert between positional and offset locations
vfile-matter — parse the YAML front matter
vfile-message — create a file message
vfile-messages-to-vscode-diagnostics — transform file messages to VS Code diagnostics
vfile-mkdirp — make sure the directory of a file exists on the file system
vfile-rename — rename the path parts of a file
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

👉 Note: see unist for projects that work with nodes.

Reporters

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

👉 Note: want to make your own reporter? 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.

Types

This package is fully typed with TypeScript. It exports the additional types BufferEncoding, Compatible, Data, DataMap, Map, Options, Reporter, ReporterSettings, and Value.

Compatibility

Projects maintained by the unified collective are compatible with all maintained versions of Node.js. As of now, that is Node.js 14.14+ and 16.0+. Our projects sometimes work with older versions, but this is not guaranteed.

Contribute

See contributing.md in vfile/.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.

Sponsor

Support this effort and give back by sponsoring on OpenCollective!

Vercel	Motif		HashiCorp		GitBook	Gatsby

Netlify	Coinbase	ThemeIsle	Expo	Boost Note	Holloway
	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

Upstream issues and maintenance review

Upstream and maintenance review

This package maintains vfile@5.3.7 under the independent @stackline/vfile name.

Source: https://github.com/vfile/vfile/tree/5d3c0de9529e4b0dd45cd7c2d9919b95e169eab9
Public npm artifact integrity: sha512-r7qlzkgErKjobAmyNIkkSpizsFPYiUPuJb5pNW1RB4JcYVZhs4lIbVqk8XPk033CV/1z8ss5pkax8SuhGpcG8g==.
Upstream issue evidence checked: 2026-09-29T00:22:18.198105+00:00.
Original license and author notices are retained.
The upstream published runtime files and declarations are hash-checked in .stackline/upstream.json. Any runtime fix is explicitly listed there.
Functional upstream suites run against the source and extracted final package. Development tools were reduced to those used by validation; full source and runtime audits must pass.
Only direct dependencies of the original Stackline portfolio are in this migration. This is not a claim that all transitive projects are maintained by Stackline.

Issue triage

The queried open-issue list contained no issue entries. This does not establish that the upstream is abandoned or bug-free. No runtime bug fix is claimed for this initial maintenance release.

The evidence query fetched the latest 100 open and 30 closed issue/PR entries and removed PRs. Closed entries were collected for context; this report does not claim an exhaustive historic review.

Release discipline

The source commit, passing CI and CodeQL, reviewed CI tarball hash, npm provenance, normal and aliased installs, and immutable GitHub release are checked before a release is complete. Published versions and tags are never replaced.

Release changes

Changelog

1.0.0

Start Stackline maintenance of the documented upstream API.
Preserve and verify published runtime files and TypeScript declarations.
Run upstream functional suites against both source and the final package.
Publish the reviewed CI artifact through GitHub Actions with provenance and immutable release evidence.

Release files and references

Package bytes, npm provenance and the immutable GitHub release were verified for this version. Security checks describe the reviewed release; documented compatibility risks and upstream reports are not blanket claims of resolution.