feat: Convert the returned dictionaries directly to json

[mikaeelghr]

Description
This would be a breaking change.

This PR fixes #393

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[sansyrox]

@mikaeelghr , I was thinking about this PR for a while and I believe I have an approach that will not break anything.

We can have two ways:

1. First, we can try casting dictionary to a Response.

2. If that doesn't work, we can return it as a json body.

Or, the second way is that we can directly allow dictionaries in the body along with string and bytes.

What do you think?

cc: @AntoineRR

[mikaeelghr]

Thanks for your comment @sansyrox.

In my opinion, your first option is pretty but it's a complex behavior and may confuse the developer. For example consider the situation that the developer needs to send Json response with a similar schema to { "status_code", "body", "type", "headers" }.

Your second option is also a good option.

BTW I think maybe with some startup configuration we can use your first method and deprecate casting dictionary to the Response object after a while.

Something like this (of course with better naming):

app = Robyn(_ file _, map_dictionary_to_json=True)

[AntoineRR]

I second @mikaeelghr on the first option, it is confusing and would prevent returning json with some special keywords. I would go for the following solution :

• returning a dictionary converts it to json, even if it has a status_code or other body field.

return {
    "field": "This is a wonderful json body",
    "body": "This does not prevent returning json"
}

• If some special fields of the response must be specified (for example headers), user should return a Response struct with the info he wants and a dict body:

return Response(
    headers = { "whatever": "header" },
    body = {
         "field": "This is a wonderful json body",
         "body": "This does not prevent returning json"
    }
)

I think at this stage we can afford breaking changes like this as Robyn hasn't reached a stable API yet. This is what 0.x versions are for after all! 🙂

A few pointers I have in mind so far to implement this:

• Detect if we return a dict body or if the body of a Response object is a dict and add a the following header to the response in these cases:

Content-Type: application/json

• Change the ActixBytesWrapper struct to accept a PyDict too

There are probably things missing but I think this is the general idea. Does it seem ok to you two?

[sansyrox]

@mikaeelghr @AntoineRR , thank you for you comments.

I agree with both of you. @mikaeelghr , at this stage we can afford breaking changes and we don't need to worry about slow migrations.

@AntoineRR , I basically agree with all the points you said 😄

And this way we can finally get rid of the type=text in the Response class.

[sansyrox]

This has been implemented.