script.liquid

{% assign skip_variants_that_already_have_skus = options.skip_variants_that_already_have_skus__boolean %}
{% assign product_options_to_keep_unabbreviated = options.product_options_to_keep_unabbreviated__array %}

{% assign allowed_characters = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789" %}

{% assign sku_base = product.handle | split: "-" | last | upcase %}

{% if event.preview %}
  {% assign sku_base = "503" %}
{% endif %}

{% assign cursor = nil %}
{% assign variants = array %}

{% for n in (1..8) %}
  {% capture query %}
    query {
      product(id: {{ product.admin_graphql_api_id | json }}) {
        id
        handle
        variants(
          first: 250
          after: {{ cursor | json }}
        ) {
          pageInfo {
            hasNextPage
            endCursor
          }
          nodes {
            inventoryItem {
              id
            }
            sku
            selectedOptions {
              name
              value
            }
          }
        }
      }
    }
  {% endcapture %}

  {% assign result = query | shopify %}

  {% if event.preview %}
    {% capture result_json %}
      {
        "data": {
          "product": {
            "variants": {
              "nodes": [
                {
                  "inventoryItem": {
                    "id": "gid://shopify/InventoryItem/1234567890"
                  },
                  {% unless skip_variants_that_already_have_skus %}"sku": "503-XL-G",{% endunless %}
                  "selectedOptions": [
                    {
                      "name": "Size",
                      "value": "XL"
                    },
                    {
                      "name": "Color",
                      "value": "Heather Grey"
                    }
                  ]
                }
              ]
            }
          }
        }
      }
    {% endcapture %}

    {% assign result = result_json | parse_json %}
  {% endif %}

  {% assign variants = variants | concat: result.data.product.variants.nodes %}

  {% if result.data.product.variants.pageInfo.hasNextPage %}
    {% assign cursor = result.data.product.variants.pageInfo.endCursor %}
  {% else %}
    {% break %}
  {% endif %}
{% endfor %}

{% for variant in variants %}
  {% if skip_variants_that_already_have_skus and variant.sku != blank %}
    {% log
      message: "variant already has a sku; skipping",
      original_sku: variant.sku
    %}
    {% continue %}
  {% endif %}

  {% assign variant_sku_generated = sku_base %}

  {% for selected_option in variant.selectedOptions %}
    {% if product_options_to_keep_unabbreviated contains selected_option.name %}
      {% assign variant_sku_generated = variant_sku_generated | append: "-" | append: selected_option.value %}

    {% else %}
      {% assign variant_option_abbreviation = "" %}
      {% assign variant_option_characters = selected_option.value | split: "" %}

      {% for variant_option_character in variant_option_characters %}
        {% if allowed_characters contains variant_option_character %}
          {% assign variant_option_abbreviation = variant_option_abbreviation | append: variant_option_character %}
        {% endif %}
      {% endfor %}

      {% if variant_option_abbreviation == blank %}
        {% assign variant_option_abbreviation = variant_option_characters[0] | upcase %}
      {% endif %}

      {% assign variant_sku_generated = variant_sku_generated | append: "-" | append: variant_option_abbreviation %}
    {% endif %}
  {% endfor %}

  {% if variant_sku_generated != variant.sku %}
    {% log
      message: "updating sku",
      original_sku: variant.sku,
      generated_sku: variant_sku_generated
    %}

    {% comment %}
      -- as of the 2024-07 API, SKUs are updated on inventory items instead of variants
    {% endcomment %}

    {% action "shopify" %}
      mutation {
        inventoryItemUpdate(
          id: {{ variant.inventoryItem.id | json }}
          input: {
            sku: {{ variant_sku_generated | json }}
          }
        ) {
          inventoryItem {
            variant {
              id
              displayName
              sku
            }
          }
          userErrors {
            field
            message
          }
        }
      }
    {% endaction %}
  {% endif %}
{% endfor %}