Shopify Functions Type Error when deploying

[adkhamllama]

I am creating app with Shopify Functions and facing problems accessing fields in Merchandise Object. Particularly I need to access product field with its properties but getting this error when I try to deploy the code with 

shopify app deploy

 The same problem happens when accessing other objects such as CartLine. The documentation (https://shopify.dev/api/functions/reference/product-discounts/graphql/common-objects/merchandise ) states that field is accessible over productVariant object. Here is the screenshot of error. 

The project template was taken from https://github.com/Shopify/function-examples/tree/main/sample-apps/discounts-tutorial 

My code:

Path: extentions/volume/src/main.rs
fn function: line 14-51

for line in cart_lines {
    if line.merchandise.product.metafield.value.products.contains(line.merchandise.product.id) {
        targets.push(Target::ProductVariant {
            id: line.merchandise.id.unwrap_or_default(),
            quantity: None,
        });
    }
}

The Input is the following: 

{
  "cart": {
    "lines": [
      {
        "quantity": 3,
        "merchandise": {
          "id": "gid://shopify/ProductVariant/40125776645833",
          "product": {
            "id": "gid://shopify/Product/6806885537821",
            "metafield": null
          }
        }
      },
      {
        "quantity": 3,
        "merchandise": {
          "id": "gid://shopify/ProductVariant/40127786613065",
          "product": {
            "id": "gid://shopify/Product/6806885008953",
            "metafield": null
          }
        }
      }
    ]
  },
  "discountNode": {
    "metafield": {
      "value": "{\"quantity\":3,\"percentage\":20}"
    }
  }
}

If I print line.merchandise object I see:

Merchandise { id: Some("gid://shopify/ProductVariant/40125287745833") }
Merchandise { id: Some("gid://shopify/ProductVariant/40125287713065") }
{"discountApplicationStrategy":"FIRST","discounts":[{"value":{"percentage":{"value":20.0}},"targets":[{"productVariant":{"id":"gid://shopify/ProductVariant/40125287745833"}},{"productVariant":{"id":"gid://shopify/ProductVariant/40125287713065"}}]}]}

product Object is missing 

Can anyone help to resolve those errors?

[Nick_Wesselman · Accepted solution]

In the tutorial and example code we provide, the input JSON is deserialized into Rust structs that are defined in the api.rs. It looks like you need to update the Rust structs to match your input query.