SyntaxError: Unexpected identifier 'assert' importing JSON on Node 22+ — use import attributes `with { type: 'json' }`

- import config from './config.json' assert { type: 'json' };
+ import config from './config.json' with { type: 'json' };
- const m = await import('./data.json', { assert: { type: 'json' } });
+ const m = await import('./data.json', { with: { type: 'json' } });

with works on Node 18.20+, 20.10+, 22+. If you must also support very old Node, load JSON via createRequire:

import { createRequire } from 'node:module';
const require = createRequire(import.meta.url);
const config = require('./config.json');

If the assert is inside node_modules (bundler configs, CLIs), upgrade that package. For Rollup configs whose output keeps assert, Rollup's --configImportAttributesKey with flag controls the emitted keyword.