json-to-ast

library2.1.0jsnpmunverified

A lightweight, zero-dependency JSON parser that produces an Abstract Syntax Tree (AST) with full location information. Version 2.1.0 supports Emoji, runs on Node >=4, and provides error messages with precise character offsets. Unlike JSON.parse, it returns a structured tree with node types like 'object', 'array', 'identifier', 'literal' and detailed 'loc' (location) data including line, column, offset, and source. Ideal for linters, formatters, code mods, and tools needing to analyze or manipulate JSON structure. Last released in 2019 with no recent updates, possibly in maintenance mode.

serialization

npm install json-to-ast

github ↗package ↗

INSTALL

IMPORT

SIG · JSON-TO-AST

json-to-ast

serializationjavascriptv2.1.0

Install

—

Import

—

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.

default

✓ import parse from 'json-to-ast'

✗ const parse = require('json-to-ast')

ESM-only since v2? Actually CJS is still supported but default export is used; both works, but ensure you handle default import correctly.

parse

✓ import { parse } from 'json-to-ast'

✗ const { parse } = require('json-to-ast')

Named export 'parse' also available; both default and named export point to same function.

type imports

✓ import type { ASTNode, ValueNode } from 'json-to-ast'

✗ import { ASTNode } from 'json-to-ast'

Type imports require 'import type' in TypeScript if using as types only.

Parses a JSON string into an AST with location info (loc: true) and source name.

import parse from 'json-to-ast'; const json = '{ "name": "Alice", "age": 30 }'; const ast = parse(json, { loc: true, source: 'example.json' }); console.log(JSON.stringify(ast, null, 2)); // Output: // { // "type": "object", // "children": [ // { // "type": "property", // "key": { "type": "identifier", "value": "name", ... }, // "value": { "type": "literal", "value": "Alice", ... } // }, // { // "type": "property", // "key": { "type": "identifier", "value": "age", ... }, // "value": { "type": "literal", "value": 30, ... } // } // ], // "loc": { ... } // }

Debug

Known issues

breakingv2.0.0 renamed 'verbose' option to 'loc' and changed node type names (e.g., 'value' to 'literal', 'key' to 'identifier').

fix

Use 'loc: true' instead of 'verbose: true'; update node type references to new names.

affects: <2.0.0

breakingv2.0.0 changed 'rawValue' to 'raw' in literal nodes.

fix

Access 'raw' instead of 'rawValue' on literal nodes.

affects: <2.0.0

breakingv2.0.0 changed 'position' property to 'loc'.

fix

Access 'loc' instead of 'position' for location data.

affects: <2.0.0

deprecatedThe package has not been updated since 2019. No future updates expected.

fix

Consider alternatives like @humanwhocodes/momoa or moo/ace for active development.

affects: >=2.1.0

gotchaDefault export and named export 'parse' both exist, but some bundlers may treat default export differently.

fix

Use named import for clarity: import { parse } from 'json-to-ast';

affects: >=2.0.0

Errors

Common errors & fixes

Error: The 'source' option must be a string

Passing a non-string value (e.g., number or object) for the 'source' option.

fix

Ensure 'source' is a string: parse(json, { source: 'file.json' })

TypeError: parse is not a function

Importing the module incorrectly in CJS or ESM environment.

fix

Use correct import: import parse from 'json-to-ast' or const parse = require('json-to-ast').default (for CJS with named export).

SyntaxError: Unexpected token in JSON at position X

The input string is not valid JSON or has extra characters. json-to-ast throws a custom error with line/column info.

fix

Check the JSON input validity; the error message includes location details (line, column, offset).

Upgrade

Version history

2.1.0latest on npm

Audit

Dependencies

No dependency data recorded yet.

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/vtrushin/json-to-ast ↗

packagehttps://www.npmjs.com/package/json-to-ast ↗