It seems like the discount function is not applying multiple discounts properly when different products with their own discounts are in the cart. I have set discountApplicationStrategy: DiscountApplicationStrategy.All, but the issue persists.
Has anyone faced a similar issue? How can I ensure that each eligible product gets its respective discount applied correctly?
import { DiscountApplicationStrategy } from "../generated/api";
/**
* @typedef {import("../generated/api").RunInput} RunInput
* @typedef {import("../generated/api").FunctionRunResult} FunctionRunResult
* @typedef {import("../generated/api").Target} Target
* @typedef {import("../generated/api").ProductVariant} ProductVariant
*/
/**
* @type {FunctionRunResult} */
const EMPTY_DISCOUNT = {
discountApplicationStrategy: DiscountApplicationStrategy.First,
discounts: [],
};
/**
* @returns {FunctionRunResult}
*/
export function run(input) {
// Parse configuration from metafield
let configuration;
try {
configuration = JSON.parse(input?.discountNode?.metafield?.value ?? "{}");
} catch (error) {
console.error("Error parsing configuration metafield:", error);
return EMPTY_DISCOUNT;
}
if (!configuration.discountValues || !Array.isArray(configuration.discountValues)) {
return EMPTY_DISCOUNT;
}
// targets will be only products that are in configuration variants
const targets = input.cart.lines
.filter(line => {
const variant = line.merchandise;
// Ensure `variants` exists and is an array
if (!configuration.variants || !Array.isArray(configuration.variants)) {
console.error("No variants defined in configuration.");
return false;
}
return configuration.variants.some(v => v === variant.id);
})
.map(line => {
const variant = /** @type {ProductVariant} */ (line.merchandise); return /** @type {Target} */ ({ productVariant: {
id: variant.id
}
});
});
if (!targets.length) {
console.error("No cart lines qualify for volume discount.");
return EMPTY_DISCOUNT;
}
const discounts = [];
// Sort discount values by quantity in descending order
const sortedDiscountValues = configuration.discountValues.sort((a, b) => b.quantity - a.quantity);
for (const target of targets) {
const line = input.cart.lines.find(line => line.merchandise?.id === target?.productVariant?.id);
if (!line) continue;
const eligibleDiscount = sortedDiscountValues.find(discountValue => line.quantity >= discountValue.quantity);
for (const discountValue of sortedDiscountValues) {
if (line.quantity >= discountValue.quantity && eligibleDiscount.quantity > 0) {
// If line quantity is enough for this discount, create a discount for this line item
const discount = {
targets: [target],
message: eligibleDiscount.discount_message,
value: eligibleDiscount.discount_type === "Percentage"
? { percentage: { value: parseFloat(eligibleDiscount.discount_percent) } }
: { fixedAmount: { amount: parseFloat(eligibleDiscount.discount_fixed) } }
};
discounts.push(discount);
// Do not break the loop, continue checking the other line items
}
}
}
return {
discounts,
discountApplicationStrategy: DiscountApplicationStrategy.All
};
};
