Debugging through a CLI

[jeromegn]

With the coming switch to Rust + ChakraCore comes a clearer and more flexible interface for debugging JavaScript. In constrast, V8's debugging interface is not very well documented and only works in Chrome or Opera (there's also an API built in C++ that works with JSON message passing, but it's a bit hard to use, not very well documented.)

ChakraCore offers a pretty simple API for debugging, it would be possible to use it directly from the CLI.

Features:

• (likely) debugger statements allows for debugging, somehow.
• (hard-ish) Interactive CLI for stepping through the stack, printing values, evaluating code
• (possibly) Add an option to automatically launch a debugger if there's an uncaught exception

Fun side effect: ChakraCore has something called "Time Travel Debugging". It allows you to step back instead of only stepping forward.