esast-util-from-estree

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[esast][] utility to transform from [estree][].

Contents

* What is this?
* When should I use this?
* Install
* Use
* API
* [fromEstree(estree[, options])](#fromestreeestree-options)
* Options
* Types
* Compatibility
* Contribute
* License

What is this?

This package applies some transforms to a cloned, given estree to make it
compatible with unist.
It:

* makes sure nodes are plain JSON
* adds unist positions
* normalizes .bigint
* remove attributes, selfClosing from JSXOpeningFragment
* removes certain discouraged fields

When should I use this?

The transform applied by this utility is often optional: estrees can be used in
most places where esast can be used, and vice versa.
But, if you come from a unist background and want to deal with JavaScript,
or want to use unist utilities with JavaScript, this helps a lot.

Install

This package is [ESM only][esm].
In Node.js (version 16+), install with [npm][]:

``sh
npm install esast-util-from-estree
`

In Deno with [esm.sh][esmsh]:

`js
import {fromEstree} from 'https://esm.sh/esast-util-from-estree@2'
`

In browsers with [esm.sh][esmsh]:

`html

`

Use

`js
import {parse} from 'acorn'
import {fromEstree} from './index.js'

// Make acorn support comments and positional info.
/* @type {Array} /
const comments = []
/* @type {import('estree').Program} /
// @ts-expect-error: acorn looks like estree.
const estree = parse(
'export function x() { / Something senseless / console.log(/(?:)/ + 1n) }',
{
sourceType: 'module',
ecmaVersion: 'latest',
locations: true,
onComment: comments
}
)
estree.comments = comments

const esast = fromEstree(estree)

console.log(esast)
`

Yields:

`js
{
type: 'Program',
body: [
{
type: 'ExportNamedDeclaration',
declaration: [Object],
specifiers: [],
source: null,
position: [Object]
}
],
sourceType: 'module',
comments: [
{
type: 'Block',
value: ' Something senseless ',
position: [Object]
}
],
position: {
start: {line: 1, column: 1, offset: 0},
end: {line: 1, column: 75, offset: 74}
}
}
`

API

This package exports the identifier [fromEstree][api-from-estree].
There is no default export.

$3

Turn an estree into an esast.

###### Parameters

* estree ([EstreeNode][estree])
— estree
* options ([Options][api-options], optional)
— configuration

###### Returns

Clean clone of estree ([UnistNode][esast]).

$3

Configuration (TypeScript Type).

###### Fields

* dirty (boolean, default: false)
— leave discouraged fields in the tree

Types

This package is fully typed with [TypeScript][].
It exports the additional type [Options][api-options].

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,
esast-util-from-estree@^2, compatible with Node.js 16.

Contribute

See [contributing.md][contributing] in [syntax-tree/.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/syntax-tree/esast-util-from-estree/workflows/main/badge.svg

[build]: https://github.com/syntax-tree/esast-util-from-estree/actions

[coverage-badge]: https://img.shields.io/codecov/c/github/syntax-tree/esast-util-from-estree.svg

[coverage]: https://codecov.io/github/syntax-tree/esast-util-from-estree

[downloads-badge]: https://img.shields.io/npm/dm/esast-util-from-estree.svg

[downloads]: https://www.npmjs.com/package/esast-util-from-estree

[size-badge]: https://img.shields.io/badge/dynamic/json?label=minzipped%20size&query=$.size.compressedSize&url=https://deno.bundlejs.com/?q=esast-util-from-estree

[size]: https://bundlejs.com/?q=esast-util-from-estree

[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/syntax-tree/unist/discussions

[npm]: https://docs.npmjs.com/cli/install

[esm]: https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c

[esmsh]: https://esm.sh

[typescript]: https://www.typescriptlang.org

[license]: license

[author]: https://wooorm.com

[health]: https://github.com/syntax-tree/.github

[contributing]: https://github.com/syntax-tree/.github/blob/main/contributing.md

[support]: https://github.com/syntax-tree/.github/blob/main/support.md

[coc]: https://github.com/syntax-tree/.github/blob/main/code-of-conduct.md

[esast]: https://github.com/syntax-tree/esast

[estree]: https://github.com/estree/estree

[api-from-estree]: #fromestreeestree-options

[api-options]: #options