E-commerce store on React Router v8, MySQL 8 and Better Auth

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// ponytail: single module-level pool; the runtime + mysql2's pool handle concurrency,
// so no globalThis singleton dance needed.
const pool = mysql.createPool(process.env.DATABASE_URL!);

export const db = drizzle({ client: pool });

import { boolean, mysqlTable, text, timestamp, varchar } from "drizzle-orm/mysql-core";

export const user = mysqlTable("user", {
  id: varchar("id", { length: 255 }).primaryKey(),
  name: text("name").notNull(),
  email: varchar("email", { length: 255 }).notNull().unique(),
  emailVerified: boolean("email_verified").notNull().default(false),
  image: text("image"),
  createdAt: timestamp("created_at").notNull().defaultNow(),
  updatedAt: timestamp("updated_at").notNull().defaultNow(),
});

export const session = mysqlTable("session", {
  id: varchar("id", { length: 255 }).primaryKey(),
  expiresAt: timestamp("expires_at").notNull(),
  token: varchar("token", { length: 255 }).notNull().unique(),
  createdAt: timestamp("created_at").notNull().defaultNow(),
  updatedAt: timestamp("updated_at").notNull(),
  ipAddress: text("ip_address"),
  userAgent: text("user_agent"),
  userId: varchar("user_id", { length: 255 })
    .notNull()
    .references(() => user.id, { onDelete: "cascade" }),
});

export const account = mysqlTable("account", {
  id: varchar("id", { length: 255 }).primaryKey(),
  accountId: text("account_id").notNull(),
  providerId: text("provider_id").notNull(),
  userId: varchar("user_id", { length: 255 })
    .notNull()
    .references(() => user.id, { onDelete: "cascade" }),
  accessToken: text("access_token"),
  refreshToken: text("refresh_token"),
  idToken: text("id_token"),
  accessTokenExpiresAt: timestamp("access_token_expires_at"),
  refreshTokenExpiresAt: timestamp("refresh_token_expires_at"),
  scope: text("scope"),
  password: text("password"),
  createdAt: timestamp("created_at").notNull().defaultNow(),
  updatedAt: timestamp("updated_at").notNull(),
});

export const verification = mysqlTable("verification", {
  id: varchar("id", { length: 255 }).primaryKey(),
  identifier: text("identifier").notNull(),
  value: text("value").notNull(),
  expiresAt: timestamp("expires_at").notNull(),
  createdAt: timestamp("created_at").notNull().defaultNow(),
  updatedAt: timestamp("updated_at").notNull().defaultNow(),
});

// Better Auth instance (self-hosted, React Router v8).
import { betterAuth } from "better-auth";
import { drizzleAdapter } from "better-auth/adapters/drizzle";
// Reuse the SAME postgres-js/Drizzle client the db slice exported in
// app/lib/db.ts — Better Auth shares the pooled `DATABASE_URL` connection.
import { db } from "./db";
import * as authSchema from "@/db/auth-schema";

export const auth = betterAuth({
  // Drizzle adapter over the shared client. The schema is passed HERE (not into
  // drizzle()) — it is the only consumer that needs it, so the db client stays
  // schema-less. ponytail: do NOT enable experimental.joins; it is the one option
  // that would make the adapter reach into db._.fullSchema.
  // ponytail: usePlural stays false (the default) — with it true Better Auth would
  // look for `sessions`/`accounts` and could bind to the analytics/ledger app-type tables.
  database: drizzleAdapter(db, { provider: "mysql", schema: authSchema }),
  // ponytail: email+password is the shortest real auth that works out of
  // the box — add socialProviders / plugins here when the app needs them.
  emailAndPassword: { enabled: true },
  secret: process.env.BETTER_AUTH_SECRET,
  baseURL: process.env.BETTER_AUTH_URL,
});

export type Session = typeof auth.$Infer.Session;

// Better Auth mounted as a React Router resource route (a route module with NO
// default component). auth.handler is framework-agnostic — (Request) => Response —
// so the GET loader and the POST/etc. action both delegate straight to it. The
// `$` splat catches every /api/auth/* sub-path Better Auth routes internally.
import type { LoaderFunctionArgs, ActionFunctionArgs } from "react-router";
import { auth } from "@/lib/auth";

export function loader({ request }: LoaderFunctionArgs) {
  return auth.handler(request);
}

export function action({ request }: ActionFunctionArgs) {
  return auth.handler(request);
}

// Session gate — the RR7 replacement for Next's Edge proxy. Protected loaders
// call `await requireAuth(request)`. Unlike the proxy's cookie-existence check,
// this does the REAL server-side validation via auth.api.getSession, then throws
// a redirect Response (React Router short-circuits the loader on a thrown Response)
// to bounce logged-out users before the protected data ever loads.
import { redirect } from "react-router";
import { auth } from "@/lib/auth";

export async function requireAuth(request: Request) {
  const session = await auth.api.getSession({ headers: request.headers });
  if (!session) {
    throw redirect("/sign-in");
  }
  return session;
}

// === file: app/db/schema.ts ===
import { relations, sql } from "drizzle-orm";
import {
  check,
  index,
  int,
  mysqlTable,
  text,
  timestamp,
  unique,
  varchar,
} from "drizzle-orm/mysql-core";
// Better Auth owns identity; we only reference its `user` table by id.
import { user } from "./auth-schema";

export type OrderStatus = "pending" | "paid" | "shipped" | "cancelled";

/** Catalog product — the marketing/display unit. Money + stock live on the
 *  variant below, never here, so a product can have many priced SKUs. */
export const products = mysqlTable(
  "products",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    slug: varchar("slug", { length: 255 }).notNull().unique(),
    name: text("name").notNull(),
    description: text("description"),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [index("idx_product_slug").on(t.slug)],
);

/** A buyable SKU under a product. Price (integer cents) and inventory live here
 *  because that's what a customer actually adds to a cart and pays for. */
export const productVariants = mysqlTable(
  "product_variants",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    productId: varchar("product_id", { length: 36 })
      .notNull()
      .references(() => products.id, { onDelete: "cascade" }),
    sku: varchar("sku", { length: 255 }).notNull().unique(),
    name: text("name").notNull(), // e.g. "Large / Black"
    // Money as integer cents — no float money in the catalog.
    priceCents: int("price_cents").notNull().default(0),
    inventoryQty: int("inventory_qty").notNull().default(0),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [index("idx_variant_product").on(t.productId)],
);

/** One open cart per shopper. userId is nullable so guests can shop before they
 *  authenticate; on login the app reassigns the guest cart to user.id. */
export const carts = mysqlTable(
  "carts",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    // Better Auth's user.id is text — match it as varchar(255). Nullable: a guest
    // cart has no user yet.
    userId: varchar("user_id", { length: 255 }).references(() => user.id, { onDelete: "cascade" }),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [index("idx_cart_user").on(t.userId)],
);

/** A variant + quantity in a cart. The composite unique keeps one row per
 *  variant per cart (the app bumps quantity instead of inserting duplicates). */
export const cartItems = mysqlTable(
  "cart_items",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    cartId: varchar("cart_id", { length: 36 })
      .notNull()
      .references(() => carts.id, { onDelete: "cascade" }),
    variantId: varchar("variant_id", { length: 36 })
      .notNull()
      .references(() => productVariants.id, { onDelete: "cascade" }),
    quantity: int("quantity").notNull().default(1),
  },
  (t) => [
    unique("cart_items_cart_variant_unique").on(t.cartId, t.variantId),
    index("idx_cart_item_cart").on(t.cartId),
  ],
);

/** A placed order. totalCents is the captured total at checkout; status walks
 *  the fulfilment states. userId is nullable to allow guest checkout. */
export const orders = mysqlTable(
  "orders",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    userId: varchar("user_id", { length: 255 }).references(() => user.id, { onDelete: "set null" }),
    status: varchar("status", { length: 32 }).$type<OrderStatus>().notNull().default("pending"),
    totalCents: int("total_cents").notNull().default(0),
    // ponytail: opaque payment-provider id (Stripe/etc.) — no provider FK needed.
    providerPaymentId: text("provider_payment_id"),
    createdAt: timestamp("created_at").notNull().defaultNow(),
  },
  (t) => [
    index("idx_order_user").on(t.userId),
    index("idx_order_status").on(t.status),
    check(
      "orders_status_check",
      sql`${t.status} in ('pending','paid','shipped','cancelled')`,
    ),
  ],
);

/** Order line item. Snapshots unitPriceCents (and the SKU string) at purchase
 *  time so re-pricing or deleting a variant never rewrites order history — the
 *  variant FK is set null on delete, the snapshot stays. */
export const orderItems = mysqlTable(
  "order_items",
  {
    id: varchar("id", { length: 36 }).primaryKey(),
    orderId: varchar("order_id", { length: 36 })
      .notNull()
      .references(() => orders.id, { onDelete: "cascade" }),
    // Keep the line even if the catalog variant is later removed.
    variantId: varchar("variant_id", { length: 36 }).references(() => productVariants.id, {
      onDelete: "set null",
    }),
    // Frozen at checkout — the SKU and price as they were when bought.
    sku: text("sku").notNull(),
    unitPriceCents: int("unit_price_cents").notNull(),
    quantity: int("quantity").notNull().default(1),
  },
  (t) => [
    // Drives the "line items for this order" lookup.
    index("idx_order_item_order").on(t.orderId),
  ],
);

export const productsRelations = relations(products, ({ many }) => ({
  variants: many(productVariants),
}));

export const productVariantsRelations = relations(
  productVariants,
  ({ one, many }) => ({
    product: one(products, {
      fields: [productVariants.productId],
      references: [products.id],
    }),
    cartItems: many(cartItems),
    orderItems: many(orderItems),
  }),
);

export const cartsRelations = relations(carts, ({ one, many }) => ({
  user: one(user, { fields: [carts.userId], references: [user.id] }),
  items: many(cartItems),
}));

export const cartItemsRelations = relations(cartItems, ({ one }) => ({
  cart: one(carts, { fields: [cartItems.cartId], references: [carts.id] }),
  variant: one(productVariants, {
    fields: [cartItems.variantId],
    references: [productVariants.id],
  }),
}));

export const ordersRelations = relations(orders, ({ one, many }) => ({
  user: one(user, { fields: [orders.userId], references: [user.id] }),
  items: many(orderItems),
}));

export const orderItemsRelations = relations(orderItems, ({ one }) => ({
  order: one(orders, { fields: [orderItems.orderId], references: [orders.id] }),
  variant: one(productVariants, {
    fields: [orderItems.variantId],
    references: [productVariants.id],
  }),
}));

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// Serverless: a small pool per short-lived instance — many instances × a big pool exhausts MySQL.
export const pool = mysql.createPool({ uri: process.env.DATABASE_URL!, connectionLimit: 2 });
export const db = drizzle({ client: pool });

import { drizzle } from "drizzle-orm/mysql2";
import mysql from "mysql2/promise";

// Long-running process: a real, reused pool (mysql2 manages idle recycling).
export const pool = mysql.createPool({ uri: process.env.DATABASE_URL!, connectionLimit: 10 });
export const db = drizzle({ client: pool });

import { drizzle } from "drizzle-orm/planetscale-serverless";
import { Client } from "@planetscale/database";

// Edge/Workers have NO TCP sockets, so mysql2 cannot run here. PlanetScale's HTTP driver
// speaks MySQL over fetch — the client that works on Workers (the MySQL analog of Neon's HTTP driver).
const client = new Client({ url: process.env.DATABASE_URL! });
export const db = drizzle({ client });