Hono•4mo ago

I want to create a middleware for hono that requires the previous middleware to have some property.

So currently I'm doing a project that have some path like this: /organization/orgSlug/functions... So I want all the methods in functions to have a valid org when I'm accessing them. This means that I need to do 2 things: - Validate that the orgSlug exists in the params - Validate that the orgSlug is pointing to an actual org. So since I'm using zod validator it's easy to pop in something like:

zValidator(param, orgParamSchema).

zValidator(param, orgParamSchema).

Now, I'm writing my own custom middleware that do this:

async (c, next) => {
 // retrieve org repository
// retrieve org in db 
// set org into variable : c.set('org', org)
}

async (c, next) => {
 // retrieve org repository
// retrieve org in db 
// set org into variable : c.set('org', org)
}

now how would I define the type for my own middleware ? I have tinkering and set the out type to something like :

out: {
  params: {
     orgSlug: string
  }
}

out: {
  params: {
     orgSlug: string
  }
}

and I got type completion for the orgSlug. However I want to also validate that the previous middleware handler need to set that orgSlug params, so for example in case I forgot to put in zValidator or make a typo in the schema, I can catch it. Is there anyway to do something like that ?

5 Replies

ambergristle•4mo ago

there isn't you can type the downstream middleware so that it "knows" that org should be available in Context, but there's no way to do that type-safely there's an open issue on github about this, but unfortunately it looks like it would take a redesign of hono's type system to add type checking between middleware, so i wouldn't expect it to be added

山 Đỗ Đình Thy SơnOP•4mo ago

ah thanks, I kinda got it now after alot of tinkering with the createMiddleware Generic function.

Lazuee•4mo ago

i think you could use the Schema from Hono you might need to chained it, because it will not be included on type ah, it's impossible to type-safe cu'z ctx.set returns void it might be possible if ctx.set can be chained and the params will be stored in Schema or something that can overload the typings

山 Đỗ Đình Thy SơnOP•4mo ago

yeah currently I can't do it. Yesterday it works because I have some wrong type in my generic 🤷‍♂️

ambergristle•4mo ago

your best option is to use something like the createHandlers factory to bind the two middleware together, but there's no way to actually type check

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I want to create a middleware for hono that requires the previous middleware to have some property.

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