destr
A faster, secure and convenient alternative for JSON.parse.
Usage
Node.js
Install dependency:
# npm
npm i destr
# yarn
yarn add destr
# pnpm
pnpm i destrImport into your Node.js project:
// ESM
import { destr, safeDestr } from "destr";
// CommonJS
const { destr, safeDestr } = require("destr");Deno
import { destr, safeDestr } from "https://deno.land/x/destr/src/index.ts";
console.log(destr('{ "deno": "yay" }'));Why?
โ Type Safe
const obj = JSON.parse("{}"); // obj type is any
const obj = destr("{}"); // obj type is unknown by default
const obj = destr<MyInterface>("{}"); // obj is well-typedโ Fast fallback to input if is not string
๐ Up to 500 faster than
JSON.parse!
// Uncaught SyntaxError: Unexpected token u in JSON at position 0
JSON.parse();
// undefined
destr();โ Fast lookup for known string values
๐ Up to 900 times faster than
JSON.parse!
// Uncaught SyntaxError: Unexpected token T in JSON at position 0
JSON.parse("TRUE");
// true
destr("TRUE");โ Fallback to original value if parse fails (empty or any plain string)
๐ Up to 900 times faster than
JSON.parse!
// Uncaught SyntaxError: Unexpected token s in JSON at position 0
JSON.parse("salam");
// "salam"
destr("salam");Note: This fails in safe/strict mode with safeDestr.
โ Avoid prototype pollution
const input = '{ "user": { "__proto__": { "isAdmin": true } } }';
// { user: { __proto__: { isAdmin: true } } }
JSON.parse(input);
// { user: {} }
destr(input);โ Strict Mode
When using safeDestr it will throw an error if the input is not a valid JSON string or parsing fails. (non string values and built-ins will be still returned as-is)
// Returns "[foo"
destr("[foo");
// Throws an error
safeDestr("[foo");Benchmarks
Locally try with pnpm benchmark. Below are results on Node.js v20.5.0 with MBA M2.
Note destr is sometimes little bit slower than JSON.parse when parsing a valid JSON string mainly because of transform to avoid prototype pollution which can lead to serious security issues if not being sanitized. In the other words, destr is better when input is not always a JSON string or from untrusted source like request body.
=== Non-string fallback ==
JSON.parse x 9,506,702 ops/sec ยฑ1.68% (92 runs sampled)
destr x 159,565,446 ops/sec ยฑ0.24% (98 runs sampled)
safeDestr x 73,624,106 ops/sec ยฑ0.39% (95 runs sampled)
sjson:
@hapi/bourne x 9,404,463 ops/sec ยฑ0.62% (96 runs sampled)
Fastest is destr
=== Known values ==
JSON.parse x 15,000,474 ops/sec ยฑ0.82% (93 runs sampled)
destr x 96,977,026 ops/sec ยฑ0.13% (101 runs sampled)
safeDestr x 47,618,310 ops/sec ยฑ0.15% (98 runs sampled)
sjson x 11,176,069 ops/sec ยฑ0.47% (93 runs sampled)
@hapi/bourne x 14,650,782 ops/sec ยฑ0.64% (93 runs sampled)
Fastest is destr
=== plain string ==
JSON.parse (try-catch) x 11,775,641 ops/sec ยฑ0.64% (95 runs sampled)
destr x 111,118,106 ops/sec ยฑ0.53% (101 runs sampled)
safeDestr x 52,455,654 ops/sec ยฑ0.21% (97 runs sampled)
sjson (try-catch) x 9,282,956 ops/sec ยฑ0.47% (96 runs sampled)
@hapi/bourne x 11,547,144 ops/sec ยฑ0.68% (96 runs sampled)
Fastest is destr
=== package.json ==
JSON.parse x 420,496 ops/sec ยฑ0.20% (98 runs sampled)
destr x 358,257 ops/sec ยฑ0.58% (98 runs sampled)
safeDestr x 351,278 ops/sec ยฑ1.10% (98 runs sampled)
sjson x 358,003 ops/sec ยฑ0.14% (102 runs sampled)
@hapi/bourne x 398,852 ops/sec ยฑ0.32% (99 runs sampled)
Fastest is JSON.parse
=== broken object ==
JSON.parse (try-catch) x 137,788 ops/sec ยฑ0.68% (98 runs sampled)
destr x 111,878 ops/sec ยฑ0.50% (98 runs sampled)
safeDestr:
sjson (try-catch) x 219,924 ops/sec ยฑ0.62% (98 runs sampled)
@hapi/bourne:
Fastest is sjson (try-catch)
License
MIT. Made with ๐