Product Discount Function - CartLine targets bug

Product Discount Function - CartLine targets bug

saisaikrishna
Shopify Partner
2 0 0

We're currently working on shopify product discounts where we're fetching the discount value via line item property and utilizing it to provide fixedAmount off on the line item with selling plan. As per the given documentation, we've referred that we could also pass theCartLineTarget along with  ProductVariantTarget within the targets as part response from product discount functions. Ref: https://shopify.dev/docs/api/functions/reference/product-discounts/graphql/common-objects/target

 

Currently we're trying to replicate the same behaviour as mentioned here within output_2.json of this example where discounts are applied on cartLines rather than productVariants:  

https://shopify.dev/docs/api/functions/reference/product-discounts/graphql#functionrunresult

 

Although the cartLine is accepted as per official documentation we're getting the below error within the partner logs stating:

"Expected one of valid values: productVariant. Got: cartLine"

Adding the relevant references below -

 

Output (STDOUT)

 

{
  "discountApplicationStrategy": "ALL",
  "discounts": [
    {
      "targets": [
        {
          "cartLine": {
            "id": "gid://shopify/CartLine/0"
          }
        }
      ],
      "message": "11 off plus additional discount based on product type value",
      "value": {
        "fixedAmount": {
          "amount": 11
        }
      }
    },
    {
      "targets": [
        {
          "cartLine": {
            "id": "gid://shopify/CartLine/1"
          }
        }
      ],
      "message": "15 off plus additional discount based on product type value",
      "value": {
        "fixedAmount": {
          "amount": 15
        }
      }
    },
    {
      "targets": [
        {
          "cartLine": {
            "id": "gid://shopify/CartLine/2"
          }
        }
      ],
      "message": "18 off plus additional discount based on product type value",
      "value": {
        "fixedAmount": {
          "amount": 18
        }
      }
    }
  ]
}

 

Error Message

 

[
  {
    "path": [
      "discounts",
      0,
      "targets",
      0
    ],
    "explanation": "Expected one of valid values: productVariant. Got: cartLine"
  },
  {
    "path": [
      "discounts",
      1,
      "targets",
      0
    ],
    "explanation": "Expected one of valid values: productVariant. Got: cartLine"
  },
  {
    "path": [
      "discounts",
      2,
      "targets",
      0
    ],
    "explanation": "Expected one of valid values: productVariant. Got: cartLine"
  }
]

 

run.graphql

 

query RunInput {
  cart {
    lines {
      id
      quantity
      attribute (key: "Product_Type") {
        key
        value
      }
      sellingPlanAllocation{
        priceAdjustments {
          perDeliveryPrice {
            amount
          }
          price {
            amount
          }
        }
        sellingPlan {
          id
          name
          recurringDeliveries
        }
      }
      merchandise {
        __typename
        ... on ProductVariant {
          id
        }
      }
    }
  }
}
 


run.js

 

// @ts-check
import { DiscountApplicationStrategy } from "../generated/api";
/**
 * @typedef {import("../generated/api").RunInput} RunInput
 * @typedef {import("../generated/api").FunctionRunResult} FunctionRunResult
 */
 
const discount = 25;
const uniqueGiftCard = 2;
 
/**
 * @type {FunctionRunResult}
 */
const EMPTY_DISCOUNT = {
  discountApplicationStrategy: DiscountApplicationStrategy.All,
  discounts: []
};

/**
 * @param {RunInput} input
 * @returns {FunctionRunResult}
 */
export function run(input) {
 
  console.error("FUNCTION IS RUNNING");
 
  const targets = input.cart.lines
    .filter(line => line.quantity >= 1 && line.sellingPlanAllocation && line.sellingPlanAllocation.priceAdjustments.length && line.sellingPlanAllocation.priceAdjustments[0] && line.sellingPlanAllocation.priceAdjustments[0].price.amount && line.attribute && line.attribute.value && line.merchandise.__typename === 'ProductVariant')
    .map(line => {
      return {
        productVariant: {
          id: line.merchandise.id
        },
        cartLine: {
          id: line.id
        },
        productTypeValue: parseFloat(line.attribute.value) // Assuming attribute value is parsable to float
      }
    });

  const discounts = targets.map(target => ({
    targets: [{ cartLine: target.cartLine }],
    message: (target.productTypeValue + ' off plus additional discount based on product type value'),
    value: {
      fixedAmount: {
        amount: target.productTypeValue // Dynamic amount based on product type
      }
    }
  }));

  /**
   * @type {FunctionRunResult}
   */
  const ACTUAL_DISCOUNT = {
    discountApplicationStrategy: DiscountApplicationStrategy.All,
    discounts: discounts
  };

  return targets.length === 0 ? EMPTY_DISCOUNT : ACTUAL_DISCOUNT;
};

 

Also note: found the error in code stating -  Type '{ cartLine: { id: string; }; }[]' is not assignable to type 'Target[]'.
Property 'productVariant' is missing in type '{ cartLine: { id: string; }; }' but required in type 'Target'.

Replies 7 (7)

tobebuilds
Shopify Partner
324 19 90

Are you using API version 2024-07? If not, you need to update your `shopify.function.extension.toml` (or `shopify.extension.toml`, depending on when you created your function).

mwade9
Shopify Partner
4 0 2

This does not fix the issue. 

 

tobebuilds
Shopify Partner
324 19 90

Well, what else have you tried? Have you run `npm run shopify app function typegen`? You probably need to regenerate TypeScript files based on the schema...

mwade9
Shopify Partner
4 0 2

Yes, that seems to work as I get " GraphQL types generated successfully." However, when viewing the error logs I see 

[  {
    "path": [
      "discounts",
      0,
      "targets",
      0
    ],
    "explanation": "Expected one of valid values: productVariant. Got: cartLine"
  }
]

 

JohnTMWK
Shopify Partner
3 0 0

I have the same problem. Supposedly, I'm using the 2024-04 API, and I also tried the 2024-07 version, but DiscountApplicationStrategy.All doesn't work. I can't apply multiple discounts.  Any help, any suggestions?
Thanks, a lot!

mwade9
Shopify Partner
4 0 2

I searched for everything it seems like, and was able to find someone that was using older documentation. I tried it and it worked for me. Here is the GitHub repo: https://github.com/Shopify/function-examples/tree/main/sample-apps/discounts/extensions/product-disc...

Hope this helps!

 

Setting discountApplicationStrategy to "All" will allow for multiple cart lines to be discounted.

discountApplicationStrategy: DiscountApplicationStrategy.All

 

JohnTMWK
Shopify Partner
3 0 0

Thank you so much for taking the time to look into this and respond to me. I will review what you sent me. Thanks again.