Registry / serialization / esast-util-from-estree

esast-util-from-estree

library2.0.0jsnpmunverified

esast-util-from-estree is a utility within the unified collective's ecosystem, specifically designed to convert an ESTree-compliant Abstract Syntax Tree (AST) into an esast, which is a unist-compliant AST for ECMAScript. Currently stable at version 2.0.0, this package plays a crucial role in enabling unist utilities to process JavaScript ASTs. It ensures that the transformed nodes are plain JSON objects, incorporates unist positional information, normalizes specific fields like `.bigint`, and prunes discouraged or redundant fields such as `attributes` and `selfClosing` from JSXOpeningFragment nodes to ensure strict unist compatibility. The package maintains the common release cadence of the unified collective, with major versions like v2.0.0 introducing breaking changes such as the shift to ESM-only distribution and requiring Node.js 16 or newer. Its primary differentiator is providing a robust, standard-compliant bridge between the ESTree format, typically generated by parsers like Acorn, and the unist specification.

serialization

npm install esast-util-from-estree

github ↗package ↗

INSTALL

IMPORT

SIG · ESAST-UTIL-FROM-ES

esast-util-from-estree

serializationjavascriptv2.0.0

Install

—

Import

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Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

fromEstree

✓ import { fromEstree } from 'esast-util-from-estree'

✗ const fromEstree = require('esast-util-from-estree')

This package is ESM-only since v2.0.0. There is no default export.

fromEstree (Deno/Browser)

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

For Deno and browser environments, use esm.sh. Append `?bundle` for browser bundling.

Options (Type)

✓ import type { Options } from 'esast-util-from-estree'

TypeScript types are shipped with the package for configuring the transformation.

This quickstart demonstrates parsing a JavaScript code string with Acorn to create an ESTree, then transforming that ESTree into an esast using `esast-util-from-estree`.

import { parse } from 'acorn'; import { fromEstree } from 'esast-util-from-estree'; // Make acorn support comments and positional info. /** @type {Array<import('acorn').Comment>} */ 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; // Transform the estree to an esast. Note: v2.0.0+ requires using the return value. const esast = fromEstree(estree); console.log(JSON.stringify(esast, null, 2));

Debug

Known issues

breakingVersion 2.0.0 of esast-util-from-estree requires Node.js 16 or higher.

fix

Upgrade your Node.js environment to version 16 or newer, or stick to an older major version of the package if you must support older Node.js versions.

affects: >=2.0.0

breakingSince version 2.0.0, this package is ESM-only. CommonJS `require()` is no longer supported.

fix

Migrate your project to use ES modules (`import` statements) or use dynamic `import()` for this package. Ensure your `package.json` has `"type": "module"` if you're using ESM in Node.js.

affects: >=2.0.0

breakingAs of v2.0.0, the `fromEstree` function no longer mutates the input ESTree. You must use the return value of the function.

fix

Change your code from `fromEstree(estree)` to `const esast = fromEstree(estree)` to correctly capture the transformed AST.

affects: >=2.0.0

gotchaThe package uses the `exports` field in its `package.json`. Directly importing internal paths (e.g., `esast-util-from-estree/lib/something`) is not supported and may break.

fix

Only import directly from the package root: `import { fromEstree } from 'esast-util-from-estree'`.

affects: >=2.0.0

Errors

Common errors & fixes

ERR_REQUIRE_ESM: require() of ES Module .../node_modules/esast-util-from-estree/index.js from .../my-script.js not supported.

Attempting to use `require()` to import esast-util-from-estree, which is an ESM-only package since v2.0.0.

fix

Convert your file to an ES module using `import { fromEstree } from 'esast-util-from-estree'` and ensure your project is configured for ESM (e.g., `"type": "module"` in `package.json`).

TypeError: Cannot read properties of undefined (reading 'type') at fromEstree (...)

The `fromEstree` function in v2.0.0+ no longer mutates its input; old code might be implicitly relying on mutation.

fix

Ensure you are using the return value: `const esast = fromEstree(estree)`. Do not expect `estree` to be transformed in place.

TypeError: (0 , esast_util_from_estree_1.fromEstree) is not a function

Attempting to import `fromEstree` as a default export or with an incorrect named import.

fix

Use a named import as there is no default export: `import { fromEstree } from 'esast-util-from-estree'`.

Upgrade

Version history

2.0.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/syntax-tree/esast-util-from-estree ↗

packagehttps://www.npmjs.com/package/esast-util-from-estree ↗