How to print custom error message instead of default "Unauthorized" or "Bad request"

[rohitcoder]

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Issue

Hi,

I'm trying to setup @fastify/passport with @fastify/cookie and @fastify/secure-session. I'm using the local strategy passport-local

After many hits and trials, I was able to set up everything, now only one issue, how to send a custom error message instead of "Unauthorized".

Below is my code for LocalStrategy

fastifyPassport.use("local", new LocalStrategy({
    usernameField: "email",
    passwordField: "password"
  }, async (email, password, done) => {
    if (!email || !password) {
      return done(null, false, { message: "Missing email or password" });
    }
    await methods.FindRecord("users", { email }).then(user => {
      if (!user) {
        return done(null, false, { message: "User not found", status: 404 });
      }
      bcrypt.compare(password, user.password, (err, isValid) => {
        if (err) {
          return done(err);
        }
        if (!isValid) {
          return done(null, false, { message: "Invalid password", status: 401 });
        }
        return done(null, user);
      });
    });
  }));

fastifyPassport.registerUserSerializer(async (user, request) => {
    return user;
})

fastifyPassport.registerUserDeserializer(async (user, request,) => {
    return user
});

This is code in fastify /login route

fastify.post("/login", { 
    preValidation: fastifyPassport.authenticate("local", {
        failureMessage: 'Invalid email or password',
        successMessage: 'Logged in successfully',
        authInfo: false,
    })
}, async (request, reply) => {
    reply.send({ message: "Logged in successfully from new response" });
})

In response i can only see "Unauthorized" instead of any other message when password/username is wrong, I can see my custom message Logged in successfully from new response only after credentials are correnct. Any help or guidance on this?

I tried fastify-flash but that was giving me some kind of decorator error.

[mcollina]

Thanks for reporting!

Can you provide steps to reproduce? We often need a reproducible example, e.g. some code that allows someone else to recreate your problem by just copying and pasting it. If it involves more than a couple of different file, create a new repository on GitHub and add a link to that.