Hi can anybody help me to implement the right/clean way of subtracting between two arrays of object. My case (backend) is that I fetch Products data from mongodb, then I also have Trolley data that is fetched from MySql, what I'm trying to do is that if product stock is subtracted by quantity in trolley & the result is lower then 0 then I will throw error. Right know my Implementation as below:
const trolleyProducts = await Trolley.findAll({
where: {
userId,
isActive: true,
},
attributes: ["id", "productId", "quantity", "notes"],
});
const products = await ProductModel.find(
{
dbId: trolleyProductIds,
},
{
_id: 0,
sku: 0,
barcode: 0,
reservedStock: 0,
sold: 0,
tags: 0,
infos: 0,
photosURL: 0,
}
);
// ******* here is my implementation *******
products.map((product) => {
trolleyProducts.map((trolley) => {
if (product.dbId === trolley.productId) {
if (product.stock - trolley.quantity < 0) {
throw {
name: "Bad Request",
message: " Stock is less than desired quantity",
};
}
}
});
});
// **************
Please let me know if there are better & cleaner approach then mine (for performance matter). Thanks :)
You can convert trolleyProducts to an object whose keys are the product IDs. That way you won't need a nested loop to find the matching product.
Also, map() should be used when the callback function returns a value and you're making an array of those values. Use forEach() if the loop is for side effect only.
const trolleyProducts = await Trolley.findAll({
where: {
userId,
isActive: true,
},
attributes: ["id", "productId", "quantity", "notes"],
});
// convert array to object.
trolleyProducts = Object.fromEntries(trolleyProducts.map(obj => [obj.productId, obj]));
const products = await ProductModel.find({
dbId: trolleyProductIds,
}, {
_id: 0,
sku: 0,
barcode: 0,
reservedStock: 0,
sold: 0,
tags: 0,
infos: 0,
photosURL: 0,
});
products.forEach((product) => {
const trolley = trolleyProducts[product.dbId]
if (trolley && product.stock - trolley.quantity < 0) {
throw {
name: "Bad Request",
message: `Stock is less than desired quantity for ${product.dbId}`,
};
}
});