@neidercode/react-native-modal/src/ModalWrapperHelper.js

This is wrapper class in react-native build on top of react-native-modal that handles multiple independent modal opening one after the other.

const modalInstances = [];
const listeners = [];

export const attachListener = (listener) => {
    if( listeners.indexOf(listener) > -1 ) {
        return;
    }
    listeners.push(listener)
}

export const pushInstance = (instance) => {
    if( modalInstances.includes(instance) ) {
        return;
    }
    modalInstances.push(instance);
    notifyInstances( modalInstances.length, modalInstances[0] )
}


export const notifyInstances = (length, topModalInstance) => {
    listeners.forEach( (listener) => {
        listener( length, topModalInstance );
    });
}

export const removeInstance = (instance) => {
    if ( instance === modalInstances[0] ) {
        modalInstances.shift();
        notifyInstances( modalInstances.length, modalInstances[0] )
    }
}

export const removeInstanceOnUnmount = (instance, listener) => {
    if( modalInstances.indexOf(instance) > -1 ) {
        modalInstances.splice(modalInstances.indexOf(instance),1)
    }
    
    if( listeners.indexOf(listener) > -1 ) {
        listeners.splice( listeners.indexOf(listener) , 1)
    }
}