jsr:@david/jsonc-morph / npm:jsonc-morph

Programmatically edit JSONC in JavaScript.

This is especially useful for making programmatic changes to JSON config files. It's not recommended for very large files as this is using jsonc-parser via Wasm under the hood.

Install

Deno:

deno add jsr:@david/jsonc-morph

Or with npm:

npm install jsonc-morph

Example

import { parse } from "@david/jsonc-morph";

const root = parse(`{
  // 1
  "data" /* 2 */: 123 // 3
} // 4`);

// get the root object
const rootObj = root.asObjectOrThrow();

// set its "data" property to have a new value
rootObj.getOrThrow("data").setValue({
  "nested": true,
});

// append a new key
rootObj.append("new_key", [456, 789, false]);

// inspect the output
assertEquals(
  root.toString(),
  `{
  // 1
  "data" /* 2 */: {
    "nested": true
  }, // 3
  "new_key": [456, 789, false]
} // 4`,
);