svelte/src/validate/js/propValidators/oncreate.ts

import usesThisOrArguments from '../utils/usesThisOrArguments';
import { Validator } from '../../';
import { Node } from '../../../interfaces';

export default function oncreate(validator: Validator, prop: Node) {
	if (prop.value.type === 'ArrowFunctionExpression') {
		if (usesThisOrArguments(prop.value.body)) {
			validator.error(
				`'oncreate' should be a function expression, not an arrow function expression`,
				{ start: prop.start, end: prop.end }
			);
		}
	}
}