Source: dynamic-data-mapping-form-renderer/src/main/resources/META-INF/resources/js/util/fields.es.js

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * This library is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
 * details.
 */

export const checkInvalidFieldNameCharacter = (character) => {
	return /[\\~`!@#$%^&*(){}[\];:"'<,.>?/\-+=|]/g.test(character);
};

export function normalizeFieldName(fieldName) {
	let nextUpperCase = false;
	let normalizedFieldName = '';

	fieldName = fieldName.trim();

	for (let i = 0; i < fieldName.length; i++) {
		let item = fieldName[i];

		if (item === ' ') {
			nextUpperCase = true;

			continue;
		}
		else if (checkInvalidFieldNameCharacter(item)) {
			continue;
		}

		if (nextUpperCase) {
			item = item.toUpperCase();

			nextUpperCase = false;
		}

		normalizedFieldName += item;
	}

	if (/^\d/.test(normalizedFieldName)) {
		normalizedFieldName = `_${normalizedFieldName}`;
	}

	return normalizedFieldName;
}