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

Contents

• unified
• What is this?
• When should I use this?
• Install
• Use
• API
  • VFile(options?)
  • file.value
  • file.cwd
  • file.path
  • file.dirname
  • file.basename
  • file.extname
  • file.stem
  • file.history
  • file.messages
  • file.data
  • VFile#toString(encoding?)
  • VFile#message(reason[, position][, origin])
  • VFile#info(reason[, position][, origin])
  • VFile#fail(reason[, position][, origin])
  • BufferEncoding
  • Compatible
  • Data
  • DataMap
  • Map
  • Options
  • Reporter
  • ReporterSettings
  • Value
  • Well-known
• List of utilities
• Reporters
• Types
• Compatibility
• Contribute
• Sponsor
• Acknowledgments
• License

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

MIT © Titus Wormer