Update Validation function templates

Author: ginmrt

checkout/javascript/cart-checkout-validation/default/schema.graphql

@@ -13,6 +13,11 @@ Scale the Functions resource limits based on the field's length.
 """
 directive @scaleLimits(rate: Float!) on FIELD_DEFINITION
 
+"""
+Requires that exactly one field must be supplied and that field must not be `null`.
+"""
+directive @oneOf on INPUT_OBJECT
+
 """
 A custom property. Attributes are used to store additional information about a Shopify resource, such as
 products, customers, or orders. Attributes are stored as key-value pairs.
@@ -363,6 +368,27 @@ type CartLineCost {
   totalAmount: MoneyV2!
 }
 
+"""
+The fetch target result. Your Function must return this data structure when generating the request.
+"""
+input CartValidationsGenerateFetchResult {
+  """
+  The attributes associated with an HTTP request.
+  """
+  request: HttpRequest
+}
+
+"""
+The output of the Function run target. The object contains the validation errors
+that display to customers and prevent them from proceeding through checkout.
+"""
+input CartValidationsGenerateRunResult {
+  """
+  The ordered list of operations to apply.
+  """
+  operations: [Operation!]!
+}
+
 """
 Whether the product is in the specified collection.
 
@@ -3030,9 +3056,9 @@ type HttpResponse {
   headers: [HttpResponseHeader!]! @deprecated(reason: "Use `header` instead.")
 
   """
-  The HTTP response body parsed as JSON. 
-  If the body is valid JSON, it will be parsed and returned as a JSON object. 
-  If parsing fails, then raw body is returned as a string. 
+  The HTTP response body parsed as JSON.
+  If the body is valid JSON, it will be parsed and returned as a JSON object.
+  If parsing fails, then raw body is returned as a string.
   Use this field when you expect the response to be JSON, or when you're dealing
   with mixed response types, meaning both JSON and non-JSON.
   Using this field reduces function instruction consumption and ensures that the data is formatted in logs.
@@ -3099,7 +3125,7 @@ type Input {
   your fetch target, and that is passed as input to the run target. For more
   information, refer to [network access for Shopify Functions](https://shopify.dev/docs/apps/build/functions/input-output/network-access).
   """
-  fetchResult: HttpResponse @restrictTarget(only: ["purchase.validation.run"])
+  fetchResult: HttpResponse @restrictTarget(only: ["purchase.validation.run", "cart.validations.generate.run"])
 
   """
   The regional and language settings that determine how the Function
@@ -3973,7 +3999,7 @@ type Localization {
   """
   The market of the active localized experience.
   """
-  market: Market!
+  market: Market! @deprecated(reason: "This `market` field will be removed in a future version of the API.")
 }
 
 """
@@ -4241,7 +4267,7 @@ type MailingAddress {
   """
   The market of the address.
   """
-  market: Market
+  market: Market @deprecated(reason: "This `market` field will be removed in a future version of the API.")
 
   """
   The full name of the customer, based on firstName and lastName.
@@ -4400,6 +4426,26 @@ type MoneyV2 {
 The root mutation for the API.
 """
 type MutationRoot {
+  """
+  Handles the Function result for the cart.validations.generate.fetch target.
+  """
+  cartValidationsGenerateFetch(
+    """
+    The result of the Function.
+    """
+    result: CartValidationsGenerateFetchResult!
+  ): Void!
+
+  """
+  Handles the Function result for the cart.validations.generate.run target.
+  """
+  cartValidationsGenerateRun(
+    """
+    The result of the Function.
+    """
+    result: CartValidationsGenerateRunResult!
+  ): Void!
+
   """
   Handles the Function result for the purchase.validation.fetch target.
   """
@@ -4431,6 +4477,16 @@ type MutationRoot {
   ): Void!
 }
 
+"""
+An operation to apply.
+"""
+input Operation @oneOf {
+  """
+  Add a performed validation.
+  """
+  validationAdd: ValidationAddOperation
+}
+
 """
 The goods and services that merchants offer to customers. Products can include details such as
 title, vendor, and custom data stored in [metafields](https://shopify.dev/docs/apps/build/custom-data).
@@ -4820,6 +4876,32 @@ type Validation implements HasMetafields {
   ): Metafield
 }
 
+"""
+Add a performed validation.
+"""
+input ValidationAddOperation {
+  """
+  Errors.
+  """
+  errors: [ValidationError!]!
+}
+
+"""
+A Function error for a path.
+"""
+input ValidationError {
+  """
+  Returns a message describing the error.
+  """
+  message: String!
+
+  """
+  Specifies the path/target for use by the UI. See [Supported checkout field targets](https://shopify.dev/docs/api/functions/reference/cart-checkout-validation/graphql#supported-checkout-field-targets)
+  for a list of supported targets.
+  """
+  target: String!
+}
+
 """
 A void type that can be used to return a null value from a mutation.
 """

checkout/javascript/cart-checkout-validation/default/shopify.extension.toml.liquid

@@ -1,4 +1,4 @@
-api_version = "2025-01"
+api_version = "2025-07"
 
 [[extensions]]
 name = "t:name"
@@ -8,11 +8,10 @@ type = "function"
 description = "t:description"
 
   [[extensions.targeting]]
-  target = "purchase.validation.run"
-  input_query = "src/run.graphql"
-  export = "run"
+  target = "cart.validations.generate.run"
+  input_query = "src/cart_validations_generate_run.graphql"
+  export = "cart-validations-generate-run"
 
   [extensions.build]
   command = ""
   path = "dist/function.wasm"
-

…alidation/default/src/run.graphql.liquid …_validations_generate_run.graphql.liquidcheckout/javascript/cart-checkout-validation/default/src/run.graphql.liquid renamed to checkout/javascript/cart-checkout-validation/default/src/cart_validations_generate_run.graphql.liquid checkout/javascript/cart-checkout-validation/default/src/run.graphql.liquid renamed to checkout/javascript/cart-checkout-validation/default/src/cart_validations_generate_run.graphql.liquid

@@ -1,4 +1,4 @@
-query RunInput {
+query CartValidationsGenerateRunInput {
   cart {
     lines {
       quantity

checkout/javascript/cart-checkout-validation/default/src/cart_validations_generate_run.liquid

@@ -0,0 +1,56 @@
+{%- if flavor contains "vanilla-js" -%}
+// @ts-check
+
+/**
+ * @typedef {import("../generated/api").CartValidationsGenerateRunInput} CartValidationsGenerateRunInput
+ * @typedef {import("../generated/api").CartValidationsGenerateRunResult} CartValidationsGenerateRunResult
+ */
+
+/**
+ * @param {CartValidationsGenerateRunInput} input
+ * @returns {CartValidationsGenerateRunResult}
+ */
+export function cartValidationsGenerateRun(input) {
+  const errors = input.cart.lines
+    .filter(({ quantity }) => quantity > 1)
+    .map(() => ({
+      message: "Not possible to order more than one of each",
+      target: "$.cart"
+    }));
+
+  const operations = [
+    {
+      validationAdd: {
+        errors
+      },
+    },
+  ];
+
+  return { operations };
+};
+{%- elsif flavor contains "typescript" -%}
+import type {
+  CartValidationsGenerateRunInput,
+  CartValidationsGenerateRunResult,
+  ValidationError,
+} from "../generated/api";
+
+export function cartValidationsGenerateRun(input: CartValidationsGenerateRunInput): CartValidationsGenerateRunResult {
+  const errors: ValidationError[] = input.cart.lines
+    .filter(({ quantity }) => quantity > 1)
+    .map(() => ({
+      message: "Not possible to order more than one of each",
+      target: "$.cart"
+    }));
+
+  const operations = [
+    {
+      validationAdd: {
+        errors
+      },
+    },
+  ];
+
+  return { operations };
+};
+{%- endif -%}

checkout/javascript/cart-checkout-validation/default/src/cart_validations_generate_run.test.liquid

@@ -0,0 +1,119 @@
+{%- if flavor contains "vanilla-js" -%}
+import { describe, it, expect } from 'vitest';
+import { cartValidationsGenerateRun } from './cart_validations_generate_run';
+
+/**
+ * @typedef {import("../generated/api").CartValidationsGenerateRunResult} CartValidationsGenerateRunResult
+ */
+
+describe('cart checkout validation function', () => {
+  it('returns an error when quantity exceeds one', () => {
+    const result = cartValidationsGenerateRun({
+      cart: {
+        lines: [
+          {
+            quantity: 3
+          }
+        ]
+      }
+    });
+    const expected = /** @type {CartValidationsGenerateRunResult} */ ({
+      operations: [
+        {
+          validationAdd: {
+            errors: [
+              {
+                message: "Not possible to order more than one of each",
+                target: "$.cart"
+              }
+            ]
+          }
+        }
+      ]
+    });
+
+    expect(result).toEqual(expected);
+  });
+
+  it('returns no errors when quantity is one', () => {
+    const result = cartValidationsGenerateRun({
+      cart: {
+        lines: [
+          {
+            quantity: 1
+          }
+        ]
+      }
+    });
+    const expected = /** @type {CartValidationsGenerateRunResult} */ ({
+      operations: [
+        {
+          validationAdd: {
+            errors: []
+          }
+        }
+      ]
+    });
+
+    expect(result).toEqual(expected);
+  });
+});
+
+{%- elsif flavor contains "typescript" -%}
+import { describe, it, expect } from 'vitest';
+import { cartValidationsGenerateRun } from './cart_validations_generate_run';
+import { CartValidationsGenerateRunResult } from "../generated/api";
+
+describe('cart checkout validation function', () => {
+  it('returns an error when quantity exceeds one', () => {
+    const result = cartValidationsGenerateRun({
+      cart: {
+        lines: [
+          {
+            quantity: 3
+          }
+        ]
+      }
+    });
+    const expected: CartValidationsGenerateRunResult = {
+      operations: [
+        {
+          validationAdd: {
+            errors: [
+              {
+                message: "Not possible to order more than one of each",
+                target: "$.cart"
+              }
+            ]
+          }
+        }
+      ]
+    };
+
+    expect(result).toEqual(expected);
+  });
+
+  it('returns no errors when quantity is one', () => {
+    const result = cartValidationsGenerateRun({
+      cart: {
+        lines: [
+          {
+            quantity: 1
+          }
+        ]
+      }
+    });
+    const expected: CartValidationsGenerateRunResult = {
+      operations: [
+        {
+          validationAdd: {
+            errors: []
+          }
+        }
+      ]
+    };
+
+    expect(result).toEqual(expected);
+  });
+});
+{%- endif -%}

checkout/javascript/cart-checkout-validation/default/src/index.liquid

@@ -1 +1 @@
-export * from './run';
+export * from './cart_validations_generate_run';