@jafps/plugin-session

Fastify plugin for session. Use typebox to ensure the session match the schema.
Inspired by @fastify/secure-session.

It depends on @fastify/cookie.

Usage

Register Plugin

import sessionPlugin from "@jafps/plugin-session";

await app.register(sessionPlugin, {
  session: {
    salt,
    schema,
    secret: "a".repeat(32)
  },
  session2: {
    salt,
    schema: Type.Object({ b: Type.String({ default: "a" }) }),
    secret: "a".repeat(32)
  }
});

declare module "fastify" {
  interface FastifySessions {
    session: { a: number };
    session2: { b: string };
  }
}

For all the sessions, it must be defined in FastifySessions and a corresponding configuration defined in options.

A key that is 32 bytes or 16 bytes salt with at least 32 bytes secret can be used.

JSON Schema

Type.Object({ b: Type.Options(Type.String(), { default: "a" }) });
Type.Object({ b: Type.Optional(Type.String()) });

Properties in JSON schema must be defined default or optional. Otherwise, the initial session will throw error.

Serialization

By using Type.Codec, the session can be serialized and deserialized automatically.

declare module "fastify" {
  interface FastifySessions {
    session: { foo: Date };
  }
}

await app.register(plugin, {
  session: {
    salt,
    schema: Type.Object({
      foo: Type.Codec(Type.Options(Type.String(), { format: "date-time" }))
        .Decode((v) => new Date(v))
        .Encode((v) => v.toISOString())
    }),
    secret: "a".repeat(32)
  }
});

req.sessions.session.set(foo, new Date());