Guard#

Suppose you have many shared local hooks.

Instead of duplicating an existing hook, you can define a shared hook scope using guard.

Guard lets you inject multiple life-cycle events into multiple routes at once. Guard is useful when you have to listen to the same life-cycle event in multiple routes, for example: logging, schema validation, or error handling.

To encapsulate all hooks into the scope, instead of writing:

app.post('/sign-up', ({ body }) => signUp(body), {
    body: t.Object({
        username: t.String(),
        password: t.String()
    })
})
.post('/sign-in', (({ body }) => signIn(body), {
    beforeHandle: isUserExists,
    body: t.Object({
        username: t.String(),
        password: t.String()
    })
})

You can group hook into guard:

app.guard(
  {
    body: t.Object({
      username: t.String(),
      password: t.String(),
    }),
  },
  app =>
    app
      .post("/sign-up", ({ body }) => signUp(body))
      .post("/sign-in", ({ body }) => signIn(body), {
        beforeHandle: isUserExists,
      })
);

Grouped Guard#

You can create group with a guard scope by adding a guard api in the second parameter, instead of nesting group and guard together.

// Instead of this
app.group("/v1", app =>
  app.guard(
    {
      body: t.Literal("Rikuhachima Aru"),
    },
    app => app.get("/student", () => "Rikuhachima Aru")
  )
);

// Do this
app.group(
  "/v1",
  {
    body: t.Literal("Rikuhachima Aru"),
  },
  app => app.get("/student", () => "Rikuhachima Aru")
);