gistfile1.txt

onChange = (e: React.ChangeEvent) => {
    e.persist();
    const {
        target: { checked, name, type, value },
    } = e;

    if (!name && process.env.NODE_ENV === 'development') {
        console.warn(
            `Change event with value '${value}' happened for an element without name prop. This is probably by mistake.`
        );
    }

    // TODO: figure out if this is really such a good idea
    this.resetError(name);

    // TODO: make this more flexible (see the work that has been done in array-parser.js for more)
    if (type === 'checkbox') {
        if (!value || value === 'on') {
            return this.setState((state) => ({
                values: {
                    ...state.values,
                    [name]: checked ? 'on' : undefined,
                },
            }));
        }

        return this.setState((state) => ({
            values: {
                ...state.values,
                [name]: (checked
                    ? (Array.isArray(state.values[name])
                            ? state.values[name]
                            : []
                        ).concat(value)
                    : (Array.isArray(state.values[name])
                            ? state.values[name]
                            : []
                        ).filter((item) => item !== value)
                ).reduce(
                    (acc, item) => (item ? (acc || []).concat(item) : acc),
                    undefined
                ),
            },
        }));
    }

    this.setValue(name, value);
};