Add a new constructor parameter to have integrated services about elysia

[Nmans01]

Having migrated from NestJS to Elysia, I like the service + controller model as well. However, I've applied it in a different way, and found that Elysia already provides the necessary tooling.

Elysia projects are comprised of plugins, and so I find that controllers and services can both be plugins, each with their own purpose. Using .derive and .decorate, you can append useful functions/logic in a service plugin, and use .use to append the service plugin to its corresponding controller plugin. I.e. I have a prismaService, which appends the prisma client to the context, an authService, which uses the prisma service to derive useful auth functions, and an authController, which uses the authService and applies the functions to auth-related endpoints.

In the case of using .derive in a service plugin, you can easily access the context object within your "derived" functions, meaning you don't have to create functions which take a fully-typed context as a argument, which seems to be a common pain point people have.

Hope this helps

[Arthurmtro]

@Nmans01 , Ohh, interesting, would you mind showing me an implementation of this concept?

[Nmans01]

A small example

// prismaService.ts
const prisma = new PrismaClient();

export const prismaService = new Elysia({ name: "prismaService" })
    .decorate({ prisma })

// authService.ts
export const authService = new Elysia({ name: "authService" })
    .use(prismaService)
    .derive((context) => ({

        getCurrentUser: async () => {
            const user = await context.prisma.user.findFirst({
                // ...
            });
            return user;
        }

    }))

// authController.ts
export const authController = new Elysia({ prefix: "/auth" })
    .use(authService)
    .get("/me", async ({ getCurrentUser }) => {
        const user = await getCurrentUser();
        return { user };
    })

// app.ts
const app = new Elysia()
    .use(authController)
    .listen(3000)

[Arthurmtro]

This is not stupid at all :o