https://github.com/vfile/vfile-is
utility to check if a vfile passes a test
https://github.com/vfile/vfile-is
file is vfile vfile-util virtual
Last synced: 10 months ago
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utility to check if a vfile passes a test
- Host: GitHub
- URL: https://github.com/vfile/vfile-is
- Owner: vfile
- License: mit
- Created: 2018-11-22T19:03:36.000Z (over 7 years ago)
- Default Branch: main
- Last Pushed: 2023-06-14T10:27:51.000Z (almost 3 years ago)
- Last Synced: 2025-07-11T21:30:06.245Z (11 months ago)
- Topics: file, is, vfile, vfile-util, virtual
- Language: JavaScript
- Homepage: https://unifiedjs.com
- Size: 81.1 KB
- Stars: 3
- Watchers: 6
- Forks: 1
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: license
Awesome Lists containing this project
README
# vfile-is
[![Build][build-badge]][build]
[![Coverage][coverage-badge]][coverage]
[![Downloads][downloads-badge]][downloads]
[![Size][size-badge]][size]
[![Sponsors][sponsors-badge]][collective]
[![Backers][backers-badge]][collective]
[![Chat][chat-badge]][chat]
[`vfile`][vfile] utility to check if a file passes a test.
## Contents
* [What is this?](#what-is-this)
* [When should I use this?](#when-should-i-use-this)
* [Install](#install)
* [Use](#use)
* [API](#api)
* [`convert(check)`](#convertcheck)
* [`is(file, check?)`](#isfile-check)
* [`Assert`](#assert)
* [`Check`](#check)
* [`CheckFields`](#checkfields)
* [`CheckFile`](#checkfile)
* [Types](#types)
* [Compatibility](#compatibility)
* [Contribute](#contribute)
* [License](#license)
## What is this?
This package is a small utility that checks that a file is a certain file.
## When should I use this?
Use this small utility if you find yourself repeating code for checking files.
## Install
This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:
```sh
npm install vfile-is
```
In Deno with [`esm.sh`][esmsh]:
```js
import {is} from 'https://esm.sh/vfile-is@3'
```
In browsers with [`esm.sh`][esmsh]:
```html
import {is} from 'https://esm.sh/vfile-is@3?bundle'
```
## Use
```js
import {VFile} from 'to-vfile'
import {is} from 'vfile-is'
is(undefined, '.js') // => false
is({}, '.js') // => false
is(new VFile({path: 'index.js'}), '.js') // => true
is(new VFile({path: 'index.js'}), '.md') // => false
is(new VFile({path: 'index.js'}), 'index.js') // => true
is(new VFile({path: 'index.js'}), 'readme.md') // => false
is(new VFile({path: 'index.js'}), '*.js') // => true
is(new VFile({path: 'index.js'}), '*.md') // => false
is(new VFile({path: 'index.js'}), {stem: 'index'}) // => true
is(new VFile({path: 'index.js'}), {stem: 'readme'}) // => false
is(new VFile({path: 'index.js'}), {stem: {prefix: 'in'}}) // => true
is(new VFile({path: 'index.js'}), {stem: {prefix: 're'}}) // => false
is(new VFile({path: 'index.js'}), {stem: {suffix: 'ex'}}) // => true
is(new VFile({path: 'index.js'}), {stem: {suffix: 'me'}}) // => false
```
## API
This package exports the identifiers [`convert`][api-convert] and
[`is`][api-is].
There is no default export.
### `convert(check)`
Create an assertion from `check`.
###### Parameters
* `check` ([`Check`][api-check], optional)
— check
###### Returns
Assertion ([`Assert`][api-assert]).
### `is(file, check?)`
Check if `file` is a specific file.
Converts `check` to an assertion and calls that assertion with `file`.
If you’re doing a lot of checks, use `convert`.
###### Parameters
* `file` (`unknown`)
— file to check (typically [`VFile`][vfile])
* `check` ([`Check`][api-check], optional)
— check
###### Returns
Whether `file` is a file and matches `check` (`boolean`).
### `Assert`
Check that a file is a `vfile` and passes a test (TypeScript type).
###### Parameters
* `file` (`unknown`)
— file to check (typically [`VFile`][vfile])
###### Returns
Whether `file` is a file and matches a bound `check` (`boolean`).
### `Check`
Different ways to check for a specific file (TypeScript type).
* if check is a glob string, checks if that glob matches `file.path`
* if check is a normal string, checks if that is `file.basename` or
`file.extname`
* if check is a function, checks whether that yields `true` when called
* if check is a normal object, checks if the given file matches the
[`CheckFields`][api-check-fields]
* if check is an array, all tests in it must pass
###### Type
```ts
type Check =
| Array
| CheckFields
| CheckFile
| string
| null
| undefined
```
### `CheckFields`
Object describing fields to values (TypeScript type).
Each key is a field in the file and each value is:
* `boolean` — whether the field exists or not
* `object` — start (prefix) and/or end (suffix) of the field
* `string` — exact value of that field
###### Type
```ts
type FieldPartial = {
prefix?: string | null | undefined
suffix?: string | null | undefined
}
type CheckFields = Record<
string,
FieldPartial | boolean | string | null | undefined
>
```
### `CheckFile`
Check if a file passes a custom test (TypeScript type).
###### Parameters
* `file` ([`VFile`][vfile])
— file to check
###### Returns
Whether the test passed for this file (`boolean`, optional).
## Types
This package is fully typed with [TypeScript][].
It exports the additional types [`Assert`][api-assert], [`Check`][api-check],
[`CheckFields`][api-check-fields], and [`CheckFile`][api-check-file].
## Compatibility
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, `vfile-is@^3`, compatible
with Node.js 16.
## Contribute
See [`contributing.md`][contributing] in [`vfile/.github`][health] for ways to
get started.
See [`support.md`][support] for ways to get help.
This project has a [code of conduct][coc].
By interacting with this repository, organization, or community you agree to
abide by its terms.
## License
[MIT][license] © [Titus Wormer][author]
[build-badge]: https://github.com/vfile/vfile-is/workflows/main/badge.svg
[build]: https://github.com/vfile/vfile-is/actions
[coverage-badge]: https://img.shields.io/codecov/c/github/vfile/vfile-is.svg
[coverage]: https://codecov.io/github/vfile/vfile-is
[downloads-badge]: https://img.shields.io/npm/dm/vfile-is.svg
[downloads]: https://www.npmjs.com/package/vfile-is
[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=vfile-is
[size]: https://bundlejs.com/?q=vfile-is
[sponsors-badge]: https://opencollective.com/unified/sponsors/badge.svg
[backers-badge]: https://opencollective.com/unified/backers/badge.svg
[collective]: https://opencollective.com/unified
[chat-badge]: https://img.shields.io/badge/chat-discussions-success.svg
[chat]: https://github.com/vfile/vfile/discussions
[npm]: https://docs.npmjs.com/cli/install
[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c
[esmsh]: https://esm.sh
[typescript]: https://www.typescriptlang.org
[contributing]: https://github.com/vfile/.github/blob/main/contributing.md
[support]: https://github.com/vfile/.github/blob/main/support.md
[health]: https://github.com/vfile/.github
[coc]: https://github.com/vfile/.github/blob/main/code-of-conduct.md
[license]: license
[author]: https://wooorm.com
[vfile]: https://github.com/vfile/vfile
[api-convert]: #convertcheck
[api-is]: #isfile-check
[api-assert]: #assert
[api-check]: #check
[api-check-fields]: #checkfields
[api-check-file]: #checkfile