Separate params and http body to avoid confusion

[olaven]

Hi! Again: thanks for this project 😄

I am wondering if it would make more sense to separate the HTTP response body from params, in Context. This makes the code more explicit and readable, in my opinion. For example:

app(post("/posts/:id/comments", ({ params, body }) => {

    console.log(`comment on post: ${params.id}`); 
    console.log(`comment data: `, body); 
    return [201, "Created comment"];
}))

Furthermore, this may cause ambiguity as to what data belongs to URL params and what data belongs to the HTTP body. Consider this (somewhat contrived) example:

interface Comment {
  post_id: string, 
  id: string, 
  text: string, 
};

app(
  // Todays solution: 
  post("/posts/:id/comments", ({ params }) => {

    //`params.id` -> ID of post or ID of comment? 
    const comment = { post_id: params.id, id: params.id, text: params.text}
    return [201, "Created comment"];
  }),
  // Proposed solution:  
  post("/posts/:id/comments", ({ params, body }) => {

    // No ambiguity between `params.id` and `body.id`
    const comment = body 
    return [201, "Created comment"];
  })
);

I implemented a solution here. If you're interested, I'll submit a PR 😄 However, I believe this breaks with Sinatra, so it's completely reasonable to dissagree.

What do you think?

EDIT: typo and added link to implementation

[olaven]

Are there any changes nececcary for the PR for this to get merged? I would be happy to implement them! 😄