Hono•4mo ago

[solved] return type of request handler

Why is 1) is fine and 2) has a type problem? 1)

  .get('/foo', async (c) => {
    return await c.html(<body/>)
  })

  .get('/foo', async (c) => {
    return await c.html(<body/>)
  })

  .get('/bar', async (c) => {
    return await render(c)
  })

  async function render(c) : Promise<HtlEscapedString> {
    return await c.html(<body/>)
  }

  .get('/bar', async (c) => {
    return await render(c)
  })

  async function render(c) : Promise<HtlEscapedString> {
    return await c.html(<body/>)
  }

I don't see it

2 Replies

Nico•4mo ago

You don’t need to await the return of c. Also in future adding await before return is redundant. You should be able to call render without a return because once render makes a return to context it will continue to the next middleware or result

tcurdt•4mo ago

Thanks, @Nico ... that wasn't the really the question though ... sorry, for the comment ... let me adjust this It seems like Promise<HtlEscapedString> is not a type that is valid to return yet it works in 1) but the tooling complains in 2) OK, I get it now

No overload matches this call.
  The last overload gave the following error.
    Argument of type '(c: Context<Env, "/bar", BlankInput>) => Promise<HtmlEscapedString>' is not assignable to parameter of type 'H<Env, "/bar", BlankInput, HandlerResponse<any>>'.
      Type '(c: Context<Env, "/bar", BlankInput>) => Promise<HtmlEscapedString>' is not assignable to type 'MiddlewareHandler<Env, "/bar", BlankInput>'.
        Type 'Promise<HtmlEscapedString>' is not assignable to type 'Promise<void | Response>'.
          Type 'HtmlEscapedString' is not assignable to type 'void | Response'.

No overload matches this call.
  The last overload gave the following error.
    Argument of type '(c: Context<Env, "/bar", BlankInput>) => Promise<HtmlEscapedString>' is not assignable to parameter of type 'H<Env, "/bar", BlankInput, HandlerResponse<any>>'.
      Type '(c: Context<Env, "/bar", BlankInput>) => Promise<HtmlEscapedString>' is not assignable to type 'MiddlewareHandler<Env, "/bar", BlankInput>'.
        Type 'Promise<HtmlEscapedString>' is not assignable to type 'Promise<void | Response>'.
          Type 'HtmlEscapedString' is not assignable to type 'void | Response'.

c.html() returns a response and hence the mismatch. So it's either

  async function render(c) : Promise<HtlEscapedString> {
    return (<body/>)
  }

  .get('/bar', async (c) => {
    return c.html(render(c))
  })

  async function render(c) : Promise<HtlEscapedString> {
    return (<body/>)
  }

  .get('/bar', async (c) => {
    return c.html(render(c))
  })

  async function render(c) : Promise<Response> {
    return c.html(<body/>)
  }

  .get('/bar', async (c) => {
    return render(c)
  })

  async function render(c) : Promise<Response> {
    return c.html(<body/>)
  }

  .get('/bar', async (c) => {
    return render(c)
  })

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[solved] return type of request handler