Fix: validate json

[thewahome]

Overview

Checks if the sample body is valid before running it. Incase it is not, it provides an error "Malformed JSON body" so that someone can see that there is a syntax error that needs to be fixed

Fixes #557

Demo

Notes

The second part in the message that contains the actual syntax error is dynamically generated and thus it's localisation is not possible.

Testing Instructions

• Log in so that you are able to send a post request
• Add an extra comma anywhere in the sample body and take note of it
• Hit enter / click run query
• Notice that an error appears saying that you have a syntax error and shows you where to find it

[MIchaelMainer]

This looks good to me. I see that Monaco has built in JSON validation as it has the red squiggle so they can find the error.

My only suggestion is to provide an action in the error message. Something like "Review the request body and fix any malformed JSON." I'd leave the parser related message, and append to the end of the message.

[MIchaelMainer]

By the way, did you see this: https://github.com/Microsoft/monaco-json? It may provide additional value for this scenario.