neotraverse

library0.6.18jsnpmunverified

neotraverse is a JavaScript/TypeScript library designed for deep traversal and in-place transformation of JavaScript objects and arrays through a recursive walk. It stands as a TypeScript rewrite and fork of the popular `js-traverse` package, aiming for API compatibility while introducing significant modernizations. The current stable version is 0.6.18, with recent patch releases indicating active maintenance. Key differentiators include its zero-dependency architecture, minimal footprint (as low as 1.38KB min+brotli for the modern build), native TypeScript support (eliminating the need for `@types/traverse`), and an ESM-first approach. It provides three distinct builds: a default ESM-only build compatible with the original `traverse` API, a 'modern' ESM-only build offering an improved API with context passed as an explicit argument, and a 'legacy' build supporting ES5 and CommonJS for broader compatibility.

serialization data

npm install neotraverse

github ↗package ↗

INSTALL

IMPORT

SIG · NEOTRAVERSE

neotraverse

serializationjavascriptv0.6.18

Install

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Import

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Disk

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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.

traverse

✓ import traverse from 'neotraverse';

✗ const traverse = require('neotraverse');

This is the default build, ESM-only (ES2022). It provides the same API as the original `traverse` package.

Traverse

✓ import { Traverse } from 'neotraverse/modern';

✗ import traverse from 'neotraverse/modern';

The modern build is ESM-only (ES2022) and provides a class-based API where traversal context is passed as the first argument `ctx` instead of `this`.

traverse

✓ const traverse = require('neotraverse/legacy');

✗ import traverse from 'neotraverse/legacy';

For compatibility with older Node.js versions or browser environments (ES5) and CommonJS projects. An ESM import is also available for this build.

Demonstrates how to use the modern `Traverse` class to recursively update negative numbers within an object/array structure in-place.

import { Traverse } from 'neotraverse/modern'; const obj = [5, 6, -3, [7, 8, -2, 1], { f: 10, g: -13 }]; // Create a new Traverse instance for the object const traverser = new Traverse(obj); // Iterate over all nodes and update negative numbers in-place traverser.forEach(function (ctx, x) { if (typeof x === 'number' && x < 0) { ctx.update(x + 128); } }); console.log(obj); // Expected output: [ 5, 6, 125, [ 7, 8, 126, 1 ], { f: 10, g: 115 } ]

Debug

Known issues

breakingThe default `neotraverse` package is ESM-only (ES2022). Projects still using CommonJS (CJS) or older Node.js versions (pre-18 for default/modern builds) will experience import errors if attempting to `require('neotraverse')`.

fix

For CJS or ES5 environments, use `require('neotraverse/legacy')`. For older Node.js versions (>=10, <18), use `neotraverse/legacy` with ESM or CJS imports.

affects: >=0.1.0

gotchaWhen using the `neotraverse/modern` build, the traversal context is passed as the first argument `ctx` to the callback function (e.g., `forEach((ctx, x) => ...)`), replacing the `this` context used in the original `traverse` and `neotraverse` default/legacy builds.

fix

Always use the `ctx` argument for methods like `ctx.update()`, `ctx.isLeaf()`, etc., in the modern build. Example: `new Traverse(obj).forEach((ctx, x) => { if (x < 0) ctx.update(x + 128); });`

affects: >=0.1.0

deprecatedThe `@types/traverse` package is no longer necessary when using `neotraverse` because the library ships with native TypeScript definitions.

fix

Remove `@types/traverse` from your project's dependencies.

affects: >=0.1.0

Errors

Common errors & fixes

TypeError: this.update is not a function

Attempting to use `this.update()` within a callback when importing from `neotraverse/modern`.

fix

Change your callback function signature to accept `ctx` as the first argument, e.g., `(ctx, x) => { ctx.update(newValue); }`.

SyntaxError: Cannot use import statement outside a module

Trying to `import traverse from 'neotraverse'` in a CommonJS (CJS) project setup without `"type": "module"` in `package.json`.

fix

If your project is CJS, use `const traverse = require('neotraverse/legacy');`. If you intend to use ESM, ensure your `package.json` specifies `"type": "module"` or use `.mjs` file extensions.

Upgrade

Version history

0.6.18latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

2 hits · last 30 days

node

Resources

githubhttps://github.com/PuruVJ/neotraverse ↗

packagehttps://www.npmjs.com/package/neotraverse ↗