fix: replace hand-scaffolded Functions with real CLI-generated ones

The user linked the app to a real Partner org and hit two live errors
running `shopify app dev`, which is exactly the verification the earlier
hand-scaffolded Functions couldn't get in this environment. Root-caused and
fixed both, then went further: regenerated both Functions from scratch via
`shopify app generate extension` (now possible — the user's session had
authenticated) instead of patching the guesses.

What broke and why:
- `shopify app config link` pulled a fresh app's (empty) remote config and
  overwrote shopify.app.toml, dropping the webhook subscriptions and
  app_proxy block — restored both, keeping the real client_id/name/scopes
  the CLI set.
- `[extensions.build.watch]` as a nested table was invalid TOML for this
  field — it's a plain `watch = [...]` array directly under
  `[extensions.build]`.
- The real failure ("doesn't have a build command or it's empty") turned
  out to be a red herring pointing at a stale filename
  (shopify.function.extension.toml, not the current shopify.extension.toml)
  — the actual problem was that `@shopify/shopify_function` was never
  installed for these extensions (confirmed: no node_modules), because
  hand-writing package.json doesn't run the install step
  `shopify app generate extension` does automatically.

Rather than keep guessing at the toolchain, regenerated both Functions for
real:
- `shopify app generate extension --template=cart_checkout_validation` and
  `--template=delivery_customization` (--flavor=vanilla-js), which produces
  a working vite/vitest-based build+test setup, real
  `@shopify/shopify-function-test-helpers` fixture testing (builds actual
  WASM and runs it via function-runner), and a generated GraphQL type file
  per extension.
- This surfaced several concrete corrections to what was hand-written
  before: the real target names are `cart.validations.generate.run` and
  `cart.delivery-options.transform.run` (not `purchase.validation.run` /
  `purchase.delivery-customization.run`), current api_version is 2026-07
  (not 2025-01), the validation output wraps errors in
  `operations: [{ validationAdd: { errors } }]` with a plain `message`
  field (not top-level `errors` with `localizedMessage`), and the rename
  operation is `deliveryOptionRename: { deliveryOptionHandle, title }` (not
  `rename: { deliveryOptionHandle, title }`).
- Rewrote each extension's `.graphql` input query to request our actual
  dd_* cart attributes (plus delivery option handles for the rename case),
  regenerated types via `npm run typegen` in each, and ported the pure
  evaluate.js decision logic (same exported function names/behavior as
  before, now proven correct against the live schema) into the adapter
  file the generator expects.
- Replaced each extension's demo fixture with ones matching our real
  logic; `npm test` inside each extension now compiles real WASM and runs
  function-runner against them — this is strictly stronger verification
  than the previous pure-JS-only unit tests (which are kept too, unchanged,
  since the evaluate.js files kept the same interface).

Repo-wide wiring: extensions/*/generated and extensions/*/dist are not
committed (matches the CLI's own per-extension .gitignore) — added
`npm run typegen:functions` (runs automatically before `npm run typecheck`
via a pretypecheck hook) and `npm run test:functions`, both now also in CI.
Root `npm install` picked these two folders up as proper npm workspace
members (they already have their own package.json from generation).

Verified: lint, typecheck, all 52 unit tests, all 8 integration tests, both
extensions' real WASM/function-runner test suites (5 fixtures total), and
both `npm run build` / `npm run build:widget` all pass.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

.eslintignore

@@ -5,3 +5,4 @@ shopify-app-remix
 */*.yml
 .shopify
 extensions/*/assets/*.js
+extensions/*/dist

.github/workflows/ci.yml

@@ -48,6 +48,8 @@ jobs:
         run: npm run typecheck
       - name: Unit tests
         run: npm test -- --run
+      - name: Function tests (real WASM build + function-runner against fixtures)
+        run: npm run test:functions
       - name: Apply migrations
         run: npx prisma migrate deploy
       - name: Integration tests (Redis-backed slot-hold concurrency, Booking flow)

README.md

@@ -35,6 +35,8 @@ runs the BullMQ worker (jobs/worker.ts) once Phase 4 makes it do anything.
 | `npm run deploy` | `shopify app deploy` — deploy extensions/functions |
 | `npm run worker` | BullMQ worker (hold-expiry, notifications) |
 | `npm run test:integration` | Redis/Postgres-backed tests (slot-hold concurrency, booking flow) — needs `docker compose up -d` |
+| `npm run test:functions` | Real WASM build + `function-runner` tests for both Shopify Functions, against fixtures |
+| `npm run typegen:functions` | Regenerate `extensions/*/generated/api.ts` from each Function's `schema.graphql` + `.graphql` query (also runs automatically before `npm run typecheck`) |
 
 ## Status
 
@@ -50,10 +52,13 @@ automatically before `npm run dev` / `npm run deploy`.
 **Functions are JavaScript, not Rust** (`extensions/validation-slot/`,
 `extensions/delivery-customization/`) — no Rust toolchain was available in
 the environment that built Phase 4, and `IMPLEMENTATION_PLAN.md` §1
-explicitly allows JS as a fallback. They (and the widget's Theme App
-Extension) were hand-scaffolded rather than generated via
-`shopify app generate extension`, which needs an interactive Partner login.
-**Before deploying either Function**, run `shopify app function schema` in
-its directory to pull the authoritative `schema.graphql` for your API
-version and confirm `src/run.graphql` still matches it — these were written
-from documented conventions, not validated against a live schema.
+explicitly allows JS as a fallback. Both were generated with
+`shopify app generate extension` (once a real Partner login was available)
+and their business logic (`src/evaluate.js` in each) is verified two ways:
+plain Vitest unit tests at the repo root (`npm test`) and real
+`function-runner` fixture tests that compile actual WASM
+(`npm run test:functions`, also in CI). `extensions/*/generated/` and
+`extensions/*/dist/` aren't committed (matching the CLI's own
+`.gitignore` for these extensions) — `npm run typegen:functions`
+regenerates the types from the committed `schema.graphql`, and building
+runs automatically as part of `npm run dev` / `test:functions`.

extensions/datetime-widget/shopify.extension.toml

@@ -1,2 +1,3 @@
 name = "Delivery Date & Time"
 type = "theme"
+uid = "4935f147-fc17-827b-2629-385b36917fa08faa33de"

extensions/delivery-customization/.gitignore

@@ -0,0 +1,2 @@
+dist
+generated

extensions/delivery-customization/locales/en.default.json

@@ -0,0 +1,4 @@
+{
+  "name": "Delivery Method Labeling",
+  "description": "Relabels delivery options at checkout with the shopper's chosen pickup/delivery date and time."
+}

extensions/delivery-customization/package.json

@@ -1,12 +1,35 @@
 {
   "name": "delivery-customization",
-  "version": "1.0.0",
-  "private": true,
+  "version": "0.0.1",
+  "license": "UNLICENSED",
   "type": "module",
   "scripts": {
-    "build": "shopify-function-build"
+    "shopify": "npm exec -- shopify",
+    "typegen": "npm exec -- shopify app function typegen",
+    "build": "npm exec -- shopify app function build",
+    "preview": "npm exec -- shopify app function run",
+    "test": "vitest"
+  },
+  "codegen": {
+    "schema": "schema.graphql",
+    "documents": "src/*.graphql",
+    "generates": {
+      "./generated/api.ts": {
+        "plugins": [
+          "typescript",
+          "typescript-operations"
+        ]
+      }
+    },
+    "config": {
+      "omitOperationSuffix": true
+    }
   },
   "dependencies": {
-    "@shopify/shopify_function": "^1.0.0"
+    "@shopify/shopify_function": "^2.0.1"
+  },
+  "devDependencies": {
+    "@shopify/shopify-function-test-helpers": "^1.0.0",
+    "vitest": "^3.2.4"
   }
 }

extensions/delivery-customization/shopify.extension.toml

@@ -1,22 +1,21 @@
-# NOTE: hand-written — see validation-slot/shopify.extension.toml for why,
-# and run `shopify app function schema` before deploying to confirm
-# src/run.graphql matches the live schema for your API version.
-
-api_version = "2025-01"
+api_version = "2026-07"
 
 [[extensions]]
-name = "Delivery Method Labeling"
+name = "t:name"
 handle = "delivery-customization"
 type = "function"
+uid = "7caef09d-bc92-c4fe-9c8c-5e43dc1b38bce5a7fa55"
+description = "t:description"
 
-[[extensions.targeting]]
-target = "purchase.delivery-customization.run"
-input_query = "src/run.graphql"
-export = "deliveryCustomizationRun"
+  [[extensions.targeting]]
+  target = "cart.delivery-options.transform.run"
+  input_query = "src/cart_delivery_options_transform_run.graphql"
+  export = "cart-delivery-options-transform-run"
 
-[extensions.build]
-command = ""
-path = "dist/function.wasm"
+  [extensions.build]
+  command = ""
+  path = "dist/function.wasm"
 
-[extensions.build.watch]
-paths = ["src/**/*.js"]
+  [extensions.ui.paths]
+  create = "/"
+  details = "/"

extensions/delivery-customization/src/cart_delivery_options_transform_run.graphql

@@ -1,4 +1,4 @@
-query RunInput {
+query CartDeliveryOptionsTransformRunInput {
   cart {
     ddMethod: attribute(key: "dd_method") {
       value

extensions/delivery-customization/src/cart_delivery_options_transform_run.js

@@ -0,0 +1,48 @@
+// @ts-check
+import { renameLabelFor } from "./evaluate.js";
+
+/**
+ * @typedef {import("../generated/api").CartDeliveryOptionsTransformRunInput} CartDeliveryOptionsTransformRunInput
+ * @typedef {import("../generated/api").CartDeliveryOptionsTransformRunResult} CartDeliveryOptionsTransformRunResult
+ */
+
+/**
+ * @type {CartDeliveryOptionsTransformRunResult}
+ */
+const NO_CHANGES = {
+  operations: [],
+};
+
+/**
+ * Relabels every presented delivery option to the shopper's actual chosen
+ * method + date, so checkout never shows a generic carrier label
+ * ("Standard", "Economy") that could be mistaken for a shipping ETA on
+ * what's actually a pickup or local-delivery order. Phase 4 doesn't yet
+ * have a per-option method mapping (that needs Phase 5's zones/rates
+ * work), so every option in the cart gets the same clarified label —
+ * reasonable since a single order only has one chosen fulfillment method
+ * today.
+ * @param {CartDeliveryOptionsTransformRunInput} input
+ * @returns {CartDeliveryOptionsTransformRunResult}
+ */
+export function cartDeliveryOptionsTransformRun(input) {
+  const decision = renameLabelFor({
+    dd_method: input.cart.ddMethod?.value,
+    dd_date: input.cart.ddDate?.value,
+  });
+
+  if (!decision.rename) {
+    return NO_CHANGES;
+  }
+
+  const operations = input.cart.deliveryGroups.flatMap((group) =>
+    group.deliveryOptions.map((option) => ({
+      deliveryOptionRename: {
+        deliveryOptionHandle: option.handle,
+        title: decision.title,
+      },
+    })),
+  );
+
+  return { operations };
+};

extensions/delivery-customization/src/evaluate.js

@@ -1,6 +1,8 @@
 // @ts-check
-// Pure decision logic — see validation-slot/src/evaluate.js for why this is
-// split out from run.js (unit-testable without a WASM build).
+// Pure decision logic, kept separate from the run.js adapter so it's
+// unit-testable directly with plain Vitest — no WASM build needed to verify
+// the actual rule (see tests/unit/delivery-customization.test.ts at the
+// repo root).
 //
 // This directly targets the DS review complaint PRODUCT_STRATEGY.md §3.1
 // names: "a stray 'estimated delivery date' on a pickup order." Renaming

extensions/delivery-customization/src/index.js

@@ -0,0 +1 @@
+export * from './cart_delivery_options_transform_run';

extensions/delivery-customization/src/run.js

@@ -1,42 +0,0 @@
-// @ts-check
-import { renameLabelFor } from "./evaluate.js";
-
-/**
- * @typedef {import("../generated/api").CartInput} RunInput
- * @typedef {import("../generated/api").FunctionRunResult} FunctionRunResult
- */
-
-/**
- * Delivery Customization Function: relabels every presented delivery
- * option to the shopper's actual chosen method + date, so checkout never
- * shows a generic carrier label ("Standard", "Economy") that could be
- * mistaken for a shipping ETA on what's actually a pickup or local-delivery
- * order. Phase 4 doesn't yet have a per-option method mapping (that needs
- * Phase 5's zones/rates work), so every option in the cart gets the same
- * clarified label — reasonable since a single order only has one chosen
- * fulfillment method today.
- * @param {RunInput} input
- * @returns {FunctionRunResult}
- */
-export function deliveryCustomizationRun(input) {
-  const attributes = {
-    dd_method: input.cart.ddMethod?.value,
-    dd_date: input.cart.ddDate?.value,
-  };
-
-  const decision = renameLabelFor(attributes);
-  if (!decision.rename) {
-    return { operations: [] };
-  }
-
-  const operations = input.cart.deliveryGroups.flatMap((group) =>
-    group.deliveryOptions.map((option) => ({
-      rename: {
-        deliveryOptionHandle: option.handle,
-        title: decision.title,
-      },
-    })),
-  );
-
-  return { operations };
-}

extensions/delivery-customization/tests/default.test.js

@@ -0,0 +1,45 @@
+import path from "path";
+import fs from "fs";
+import { describe, beforeAll, test, expect } from "vitest";
+import { buildFunction, getFunctionInfo, loadSchema, loadInputQuery, loadFixture, validateTestAssets, runFunction } from "@shopify/shopify-function-test-helpers";
+
+describe("Default Integration Test", () => {
+  let schema;
+  let functionDir;
+  let functionInfo;
+  let schemaPath;
+  let targeting;
+  let functionRunnerPath;
+  let wasmPath;
+
+  beforeAll(async () => {
+    functionDir = path.dirname(__dirname);
+    await buildFunction(functionDir);
+    functionInfo = await getFunctionInfo(functionDir);
+    ({ schemaPath, functionRunnerPath, wasmPath, targeting } = functionInfo);
+    schema = await loadSchema(schemaPath);
+  }, 45000);
+
+  const fixturesDir = path.join(__dirname, "fixtures");
+  const fixtureFiles = fs
+    .readdirSync(fixturesDir)
+    .filter((file) => file.endsWith(".json"))
+    .map((file) => path.join(fixturesDir, file));
+
+  fixtureFiles.forEach((fixtureFile) => {
+    test(`runs ${path.relative(fixturesDir, fixtureFile)}`, async () => {
+      const fixture = await loadFixture(fixtureFile);
+      const targetInputQueryPath = targeting[fixture.target].inputQueryPath;
+      const inputQueryAST = await loadInputQuery(targetInputQueryPath);
+
+      const validationResult = await validateTestAssets({ schema, fixture, inputQueryAST });
+      expect(validationResult.inputQuery.errors).toEqual([]);
+      expect(validationResult.inputFixture.errors).toEqual([]);
+      expect(validationResult.outputFixture.errors).toEqual([]);
+
+      const runResult = await runFunction(fixture, functionRunnerPath, wasmPath, targetInputQueryPath, schemaPath);
+      expect(runResult.error).toBeNull();
+      expect(runResult.result.output).toEqual(fixture.expectedOutput);
+    }, 10000);
+  });
+});

extensions/delivery-customization/tests/fixtures/no-operations.json

@@ -0,0 +1,20 @@
+{
+  "payload": {
+    "export": "cart-delivery-options-transform-run",
+    "target": "cart.delivery-options.transform.run",
+    "input": {
+      "cart": {
+        "ddMethod": null,
+        "ddDate": null,
+        "deliveryGroups": [
+          {
+            "deliveryOptions": [{ "handle": "standard-shipping" }]
+          }
+        ]
+      }
+    },
+    "output": {
+      "operations": []
+    }
+  }
+}

extensions/delivery-customization/tests/fixtures/renames-pickup-option.json

@@ -0,0 +1,33 @@
+{
+  "payload": {
+    "export": "cart-delivery-options-transform-run",
+    "target": "cart.delivery-options.transform.run",
+    "input": {
+      "cart": {
+        "ddMethod": { "value": "PICKUP" },
+        "ddDate": { "value": "2026-08-25" },
+        "deliveryGroups": [
+          {
+            "deliveryOptions": [{ "handle": "standard-shipping" }, { "handle": "express-shipping" }]
+          }
+        ]
+      }
+    },
+    "output": {
+      "operations": [
+        {
+          "deliveryOptionRename": {
+            "deliveryOptionHandle": "standard-shipping",
+            "title": "Pickup — 2026-08-25"
+          }
+        },
+        {
+          "deliveryOptionRename": {
+            "deliveryOptionHandle": "express-shipping",
+            "title": "Pickup — 2026-08-25"
+          }
+        }
+      ]
+    }
+  }
+}

extensions/delivery-customization/vite.config.js

@@ -0,0 +1 @@
+// Prevents inheritance from parent Remix project

extensions/delivery-customization/vitest.config.js

@@ -0,0 +1,8 @@
+export default {
+  test: {
+    forceRerunTriggers: [
+      '**/tests/fixtures/**',
+      '**/src/**',
+    ],
+  },
+};

extensions/validation-slot/.gitignore

@@ -0,0 +1,2 @@
+dist
+generated

extensions/validation-slot/locales/en.default.json

@@ -0,0 +1,4 @@
+{
+  "name": "Delivery Slot Validation",
+  "description": "Blocks checkout if no delivery date/time slot was selected."
+}

extensions/validation-slot/package.json

@@ -1,12 +1,35 @@
 {
   "name": "validation-slot",
-  "version": "1.0.0",
-  "private": true,
+  "version": "0.0.1",
+  "license": "UNLICENSED",
   "type": "module",
   "scripts": {
-    "build": "shopify-function-build"
+    "shopify": "npm exec -- shopify",
+    "typegen": "npm exec -- shopify app function typegen",
+    "build": "npm exec -- shopify app function build",
+    "preview": "npm exec -- shopify app function run",
+    "test": "vitest"
+  },
+  "codegen": {
+    "schema": "schema.graphql",
+    "documents": "src/*.graphql",
+    "generates": {
+      "./generated/api.ts": {
+        "plugins": [
+          "typescript",
+          "typescript-operations"
+        ]
+      }
+    },
+    "config": {
+      "omitOperationSuffix": true
+    }
   },
   "dependencies": {
-    "@shopify/shopify_function": "^1.0.0"
+    "@shopify/shopify_function": "^2.0.1"
+  },
+  "devDependencies": {
+    "@shopify/shopify-function-test-helpers": "^1.0.0",
+    "vitest": "^3.2.4"
   }
 }

extensions/validation-slot/shopify.extension.toml

@@ -1,27 +1,17 @@
-# NOTE: hand-written (shopify app generate extension needs an interactive
-# Partner login unavailable in this environment — see README.md). This
-# mirrors Shopify's documented structure for a JS Cart/Checkout Validation
-# Function as closely as possible from training knowledge, but has not been
-# validated against a live `shopify app function schema` pull. Before
-# deploying: run `shopify app function schema` in this directory to fetch
-# the authoritative schema.graphql for your app's API version, confirm
-# src/run.graphql still matches it, and fix up anything that's drifted.
-
-api_version = "2025-01"
+api_version = "2026-07"
 
 [[extensions]]
-name = "Delivery Slot Validation"
+name = "t:name"
 handle = "validation-slot"
 type = "function"
+uid = "f5265178-4064-010b-5acf-a7b68096a1d29be8d5da"
+description = "t:description"
 
-[[extensions.targeting]]
-target = "purchase.validation.run"
-input_query = "src/run.graphql"
-export = "cartCheckoutValidationRun"
+  [[extensions.targeting]]
+  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"
-
-[extensions.build.watch]
-paths = ["src/**/*.js"]
+  [extensions.build]
+  command = ""
+  path = "dist/function.wasm"

extensions/validation-slot/src/cart_validations_generate_run.graphql

@@ -1,4 +1,4 @@
-query RunInput {
+query CartValidationsGenerateRunInput {
   cart {
     ddMethod: attribute(key: "dd_method") {
       value

extensions/validation-slot/src/cart_validations_generate_run.js

@@ -2,8 +2,8 @@
 import { evaluateCartAttributes } from "./evaluate.js";
 
 /**
- * @typedef {import("../generated/api").CartInput} RunInput
- * @typedef {import("../generated/api").FunctionRunResult} FunctionRunResult
+ * @typedef {import("../generated/api").CartValidationsGenerateRunInput} CartValidationsGenerateRunInput
+ * @typedef {import("../generated/api").CartValidationsGenerateRunResult} CartValidationsGenerateRunResult
  */
 
 const ERROR_MESSAGE = {
@@ -14,10 +14,10 @@ const ERROR_MESSAGE = {
 /**
  * Cart & Checkout Validation Function — the server-side enforcement half of
  * the widget/Function split (see evaluate.js for the full scope note).
- * @param {RunInput} input
- * @returns {FunctionRunResult}
+ * @param {CartValidationsGenerateRunInput} input
+ * @returns {CartValidationsGenerateRunResult}
  */
-export function cartCheckoutValidationRun(input) {
+export function cartValidationsGenerateRun(input) {
   const attributes = {
     dd_method: input.cart.ddMethod?.value,
     dd_date: input.cart.ddDate?.value,
@@ -28,16 +28,13 @@ export function cartCheckoutValidationRun(input) {
 
   const result = evaluateCartAttributes(attributes);
 
-  if (result.valid) {
-    return { errors: [] };
-  }
-
   return {
-    errors: [
+    operations: [
       {
-        localizedMessage: ERROR_MESSAGE[result.reason],
-        target: "cart",
+        validationAdd: {
+          errors: result.valid ? [] : [{ message: ERROR_MESSAGE[result.reason], target: "$.cart" }],
+        },
       },
     ],
   };
-}
+};

extensions/validation-slot/src/evaluate.js

@@ -1,11 +1,14 @@
 // @ts-check
-// Pure decision logic, kept separate from run.js so it can be unit-tested
-// directly with plain Vitest — no WASM build or function-runner needed to
-// verify the actual rule. This is the enforcement half of the "widget
-// collects, Function enforces" split (CLAUDE.md non-negotiable): a shopper
-// who clears the cart attribute, calls the cart API directly, or otherwise
-// bypasses the storefront widget still cannot complete checkout, because
-// this runs server-side inside Shopify's own checkout, not in the browser.
+// Pure decision logic, kept separate from the run.js adapter so it can be
+// unit-tested directly with plain Vitest (see
+// tests/unit/validation-slot.test.ts at the repo root) as well as through
+// the real function-runner fixtures in tests/fixtures/ here.
+//
+// This is the enforcement half of the "widget collects, Function enforces"
+// split (CLAUDE.md non-negotiable): a shopper who clears the cart
+// attribute, calls the cart API directly, or otherwise bypasses the
+// storefront widget still cannot complete checkout, because this runs
+// server-side inside Shopify's own checkout, not in the browser.
 //
 // Scope note (Phase 4): every order on shops that activate this Function is
 // currently treated as requiring a schedule selection — there's no
@@ -17,8 +20,8 @@
 // capacity snapshot at the moment checkout completes ("has since been
 // taken" in PRODUCT_STRATEGY.md §3.1) — Functions can't call our DB, and
 // building a metafield-snapshot refresh pipeline for that is real,
-// unscoped work. The 10-minute hold TTL (holds.server.ts) is the mitigation
-// for that specific race in the meantime.
+// unscoped work. The 10-minute hold TTL (app/services/holds.server.ts) is
+// the mitigation for that specific race in the meantime.
 
 const REQUIRED_ATTRIBUTES = ["dd_method", "dd_date", "dd_start_min", "dd_end_min", "dd_location_id"];
 

extensions/validation-slot/src/index.js

@@ -0,0 +1 @@
+export * from './cart_validations_generate_run';

extensions/validation-slot/tests/default.test.js

@@ -0,0 +1,45 @@
+import path from "path";
+import fs from "fs";
+import { describe, beforeAll, test, expect } from "vitest";
+import { buildFunction, getFunctionInfo, loadSchema, loadInputQuery, loadFixture, validateTestAssets, runFunction } from "@shopify/shopify-function-test-helpers";
+
+describe("Default Integration Test", () => {
+  let schema;
+  let functionDir;
+  let functionInfo;
+  let schemaPath;
+  let targeting;
+  let functionRunnerPath;
+  let wasmPath;
+
+  beforeAll(async () => {
+    functionDir = path.dirname(__dirname);
+    await buildFunction(functionDir);
+    functionInfo = await getFunctionInfo(functionDir);
+    ({ schemaPath, functionRunnerPath, wasmPath, targeting } = functionInfo);
+    schema = await loadSchema(schemaPath);
+  }, 45000);
+
+  const fixturesDir = path.join(__dirname, "fixtures");
+  const fixtureFiles = fs
+    .readdirSync(fixturesDir)
+    .filter((file) => file.endsWith(".json"))
+    .map((file) => path.join(fixturesDir, file));
+
+  fixtureFiles.forEach((fixtureFile) => {
+    test(`runs ${path.relative(fixturesDir, fixtureFile)}`, async () => {
+      const fixture = await loadFixture(fixtureFile);
+      const targetInputQueryPath = targeting[fixture.target].inputQueryPath;
+      const inputQueryAST = await loadInputQuery(targetInputQueryPath);
+
+      const validationResult = await validateTestAssets({ schema, fixture, inputQueryAST });
+      expect(validationResult.inputQuery.errors).toEqual([]);
+      expect(validationResult.inputFixture.errors).toEqual([]);
+      expect(validationResult.outputFixture.errors).toEqual([]);
+
+      const runResult = await runFunction(fixture, functionRunnerPath, wasmPath, targetInputQueryPath, schemaPath);
+      expect(runResult.error).toBeNull();
+      expect(runResult.result.output).toEqual(fixture.expectedOutput);
+    }, 10000);
+  });
+});

extensions/validation-slot/tests/fixtures/complete-selection-passes.json

@@ -0,0 +1,24 @@
+{
+  "payload": {
+    "export": "cart-validations-generate-run",
+    "target": "cart.validations.generate.run",
+    "input": {
+      "cart": {
+        "ddMethod": { "value": "PICKUP" },
+        "ddDate": { "value": "2026-08-25" },
+        "ddStartMin": { "value": "540" },
+        "ddEndMin": { "value": "600" },
+        "ddLocationId": { "value": "loc_123" }
+      }
+    },
+    "output": {
+      "operations": [
+        {
+          "validationAdd": {
+            "errors": []
+          }
+        }
+      ]
+    }
+  }
+}

extensions/validation-slot/tests/fixtures/incomplete-selection-blocks-checkout.json

@@ -0,0 +1,29 @@
+{
+  "payload": {
+    "export": "cart-validations-generate-run",
+    "target": "cart.validations.generate.run",
+    "input": {
+      "cart": {
+        "ddMethod": { "value": "PICKUP" },
+        "ddDate": { "value": "2026-08-25" },
+        "ddStartMin": null,
+        "ddEndMin": null,
+        "ddLocationId": { "value": "loc_123" }
+      }
+    },
+    "output": {
+      "operations": [
+        {
+          "validationAdd": {
+            "errors": [
+              {
+                "message": "Your delivery date/time selection is incomplete — please choose it again.",
+                "target": "$.cart"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  }
+}

extensions/validation-slot/tests/fixtures/missing-selection-blocks-checkout.json

@@ -0,0 +1,29 @@
+{
+  "payload": {
+    "export": "cart-validations-generate-run",
+    "target": "cart.validations.generate.run",
+    "input": {
+      "cart": {
+        "ddMethod": null,
+        "ddDate": null,
+        "ddStartMin": null,
+        "ddEndMin": null,
+        "ddLocationId": null
+      }
+    },
+    "output": {
+      "operations": [
+        {
+          "validationAdd": {
+            "errors": [
+              {
+                "message": "Please choose a delivery date and time before checking out.",
+                "target": "$.cart"
+              }
+            ]
+          }
+        }
+      ]
+    }
+  }
+}

extensions/validation-slot/vite.config.js

@@ -0,0 +1 @@
+// Prevents inheritance from parent Remix project

extensions/validation-slot/vitest.config.js

@@ -0,0 +1,8 @@
+export default {
+  test: {
+    forceRerunTriggers: [
+      '**/tests/fixtures/**',
+      '**/src/**',
+    ],
+  },
+};

package.json

@@ -15,7 +15,10 @@
     "docker-start": "npm run setup && npm run start",
     "setup": "prisma generate && prisma migrate deploy",
     "lint": "eslint --cache --cache-location ./node_modules/.cache/eslint .",
+    "typegen:functions": "npm --prefix extensions/validation-slot run typegen && npm --prefix extensions/delivery-customization run typegen",
+    "pretypecheck": "npm run typegen:functions",
     "typecheck": "tsc --noEmit",
+    "test:functions": "npm --prefix extensions/validation-slot test && npm --prefix extensions/delivery-customization test",
     "test": "vitest",
     "test:integration": "vitest run --config vitest.integration.config.ts",
     "test:e2e": "playwright test",

shopify.app.toml

@@ -1,25 +1,19 @@
-# This file stores configurations for your Shopify app.
-# Learn more at https://shopify.dev/docs/apps/tools/cli/configuration
+# Learn more about configuring your app at https://shopify.dev/docs/apps/tools/cli/configuration
 
-client_id = ""
-name = "delivery-datetime-app"
-application_url = "https://replace-with-your-tunnel-url.example.com"
+client_id = "890f611da9f31c1a8e3183b5300b2f53"
+name = "Metatron-delivery"
+application_url = "https://shopify.dev/apps/default-app-home"
 embedded = true
 
 [access_scopes]
-# Minimum scopes for the v1 (Phase 0-4) feature set. Add more only when a
-# feature in IMPLEMENTATION_PLAN.md actually needs it.
-scopes = "read_products,read_customers,read_orders,write_orders,read_locations,read_metaobjects,write_metaobjects,write_cart_transforms,write_delivery_customizations,write_payment_customizations,read_markets,read_locales"
+# Learn more at https://shopify.dev/docs/apps/tools/cli/configuration#access_scopes
+scopes = "read_customers,read_locales,read_locations,read_markets,read_metaobjects,read_orders,read_products,write_cart_transforms,write_delivery_customizations,write_metaobjects,write_orders,write_payment_customizations"
 
 [auth]
-redirect_urls = [
-  "https://replace-with-your-tunnel-url.example.com/auth/callback",
-  "https://replace-with-your-tunnel-url.example.com/auth/shopify/callback",
-  "https://replace-with-your-tunnel-url.example.com/api/auth/callback"
-]
+redirect_urls = [ "https://shopify.dev/apps/default-app-home/api/auth" ]
 
 [webhooks]
-api_version = "2024-10"
+api_version = "2026-10"
 
   # Handled by: app/routes/webhooks.app.uninstalled.tsx
   [[webhooks.subscriptions]]
@@ -31,17 +25,17 @@ api_version = "2024-10"
   uri = "/webhooks/app/scopes_update"
   topics = ["app/scopes_update"]
 
-  # Handled by: app/routes/webhooks.orders.create.tsx (Phase 4)
+  # Handled by: app/routes/webhooks.orders.create.tsx
   [[webhooks.subscriptions]]
   uri = "/webhooks/orders/create"
   topics = ["orders/create"]
 
-  # Handled by: app/routes/webhooks.orders.updated.tsx (Phase 4)
+  # Handled by: app/routes/webhooks.orders.updated.tsx
   [[webhooks.subscriptions]]
   uri = "/webhooks/orders/updated"
   topics = ["orders/updated"]
 
-  # Handled by: app/routes/webhooks.orders.cancelled.tsx (Phase 4)
+  # Handled by: app/routes/webhooks.orders.cancelled.tsx
   [[webhooks.subscriptions]]
   uri = "/webhooks/orders/cancelled"
   topics = ["orders/cancelled"]
@@ -63,7 +57,12 @@ api_version = "2024-10"
   compliance_topics = ["shop/redact"]
 
 # App proxy so the storefront Theme App Extension can call our backend
-# without CORS issues (see IMPLEMENTATION_PLAN.md §5.3).
+# without CORS issues (see IMPLEMENTATION_PLAN.md §5.3). `shopify app dev`
+# points this at your dev tunnel automatically when
+# automatically_update_urls_on_dev is true (see [build] below); if it
+# doesn't, set it manually to `<your-tunnel-url>/apps/scheduling` — the
+# Remix routes it forwards to (apps.scheduling.*.tsx) assume that exact
+# prefix.
 [app_proxy]
 url = "https://replace-with-your-tunnel-url.example.com/apps/scheduling"
 subpath = "scheduling"
@@ -71,3 +70,4 @@ prefix = "apps"
 
 [build]
 include_config_on_deploy = true
+automatically_update_urls_on_dev = true