T
TanStack•5mo ago
absent-sapphire

DB Transaction, AsyncLocalStorage and Middleware

Hello, I'm trying to add an abstraction for db transaction using Drizzle-ORM. For this I want to create a transaction and put it in the AsyncLocalStorage of Node.js, so that I can retrieve it using a function in my repositories without passing the transaction everywhere. Can I do this sort of things with the middleware ? 
export const transactionMiddleware = createMiddleware().server(async ({ next }) => {
    try {
        const result = await db.transaction(async (tx) => {
            const handlerResult = await dbTransactionLocalStorage.run(tx, async () => {
                return await next();
            });
            return handlerResult;
        });
        return result;
    }
    catch (error) {
        console.error("Transaction failed:", error);
        throw error;
    }
});

export const dbTransactionLocalStorage = new AsyncLocalStorage<TransactionClient>();

export const getDbClient = () => {
    const transactionalClient = dbTransactionLocalStorage.getStore();
    return transactionalClient || db;
}
export const transactionMiddleware = createMiddleware().server(async ({ next }) => {
    try {
        const result = await db.transaction(async (tx) => {
            const handlerResult = await dbTransactionLocalStorage.run(tx, async () => {
                return await next();
            });
            return handlerResult;
        });
        return result;
    }
    catch (error) {
        console.error("Transaction failed:", error);
        throw error;
    }
});

export const dbTransactionLocalStorage = new AsyncLocalStorage<TransactionClient>();

export const getDbClient = () => {
    const transactionalClient = dbTransactionLocalStorage.getStore();
    return transactionalClient || db;
}
Because at first this seems to work but then after like 5-10 seconds the server just shutdown with only an error code (no other information): 
Process finished with exit code -1073741819 (0xC0000005)
Process finished with exit code -1073741819 (0xC0000005)
Thanks in advance :).
1 Reply
foreign-sapphire
foreign-sapphire•5mo ago
Hey, I usually put things inside the "event.context" and then retrieve them wherever I need. Something like this could work: 
export const transactionMiddleware = createMiddleware().server(async ({ next }) => {
  const event = getEvent()
  const db = createDatabaseClient()
  event.context.db = db // You can access this value using "getEvent().context.db"

  return next({
    context: {
      db, // You can access this value accessing the context param directly
    },
  })
})

export function getDatabase() { // Use this function anywhere
  const event = getEvent()
  return event.context.db
}
export const transactionMiddleware = createMiddleware().server(async ({ next }) => {
  const event = getEvent()
  const db = createDatabaseClient()
  event.context.db = db // You can access this value using "getEvent().context.db"

  return next({
    context: {
      db, // You can access this value accessing the context param directly
    },
  })
})

export function getDatabase() { // Use this function anywhere
  const event = getEvent()
  return event.context.db
}
You can register it as global middleware, so the db is always available on the context

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