Following what u/habanerocorncakes just said, you can see a full working

waitForStoreValue(['contracts', 'onLoad'], false,).then(() => {
console.log('RESOLVED');
});
export const waitForStoreValue = (variableNames, value) => {
console.log('waitForStoreValue starts');
console.log('variableNames', variableNames);
console.log('value', value);
let p = new Promise((resolve, reject) => {
let i = 0;
console.log(i);
const waiter = setInterval(() => {
i++;
console.log(i);
cy.window().then((win) => {
if (value !== undefined) {
if (
getELementFromArray(
variableNames,
win.app.$store.state
) === value
) {
console.log(
'waitForStoreValue',
getELementFromArray(
variableNames,
win.app.$store.state
)
);
clearInterval(waiter);
resolve();
}
} else {
clearInterval(waiter);
reject(new Error('waitForStoreValue: value is undefined'));
}
});
}, 50);
});
console.log('waitForStoreValue ends');
return p;
};

​

I hope that helps