toDotNotation.ts

export const toDotNotation = (obj: object, prefix = ''): DotNotationObject => {
    return Object.entries(obj)
        .reduce<DotNotationObject>((acc, [key, value]) => {
            const k = prefix ? `${prefix}.${key}` : key;

            if (value && typeof value === 'object') {
                if (Array.isArray(value)) {
                    return value.reduce((arrayAcc, item, index) => {
                        const kA = `${k}[${index}]`;

                        if (item && typeof item === 'object')
                            return { ...arrayAcc, ...toDotNotation(item, kA) };

                        return { ...arrayAcc, [kA]: item };
                    }, acc);
                }

                return { ...acc, ...toDotNotation(value, k) };
            }

            return { ...acc, [k]: value };
        }, {});
};