esast-util-from-estree
esast utility to transform from estree.
Contents
What is this?
This package applies some transforms to a given estree to make it compatible with unist. It:
- makes sure nodes are plain JSON
- adds unist positions
- normalizes
.bigint
- remove
attributes
,selfClosing
fromJSXOpeningFragment
- 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. In Node.js (version 14.14+ and 16.0+), install with npm:
npm install esast-util-from-estree
In Deno with esm.sh
:
import {fromEstree} from 'https://esm.sh/esast-util-from-estree@1'
In browsers with esm.sh
:
<script type="module">
import {fromEstree} from 'https://esm.sh/esast-util-from-estree@1?bundle'
</script>
Use
import {parse} from 'acorn'
import {fromEstree} from 'esast-util-from-estree'
// Make acorn support comments and positional info.
const comments = []
const esast = parse(
'export function x() { /* Something senseless */ console.log(/(?:)/ + 1n) }',
{sourceType: 'module', locations: true, onComment: comments}
)
esast.comments = comments
console.log(fromEstree(esast))
Yields:
{
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
. There is no default export.
fromEstree(estree[, options])
Turn an estree into an esast.
Parameters
estree
(EstreeNode
) — estreeoptions
(Options
, optional) — configuration
Returns
esast (UnistNode
).
Options
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
.
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 syntax-tree/.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.