highlight runtime errors

[saimeunt]

Fixes #99

[mazurroman]

@saimeunt thank you for the contribution!

After looking at the app it looks like the error highlighting in Instructions as well as in CASM is working pretty well. However, I do not see the error being highlighted in Sierra, can you look into that?

Also, can you move the execution to the "error" statement? Currently the execution is at the beginning at "Step 1", but we want to move it to the error in case of an error.

Please reach out in case of any questions.

[saimeunt]

@mazurroman I've moved the execution step to the error instruction on program run.

Regarding the SIERRA issue, I noticed the last execution trace is always pointing to the final return exiting the program and this instruction is not mapped to any SIERRA code 🤔 (no active index either).
Maybe the assumption "the last trace item is the runtime error" is untrue?
In this scenario I'm unsure how to proceed in order to pinpoint the SIERRA runtime error, I will try compiling and running the examples that panic with Cairo on my machine to get more info.

[barabanovro]

Hey @saimeunt, sorry for the confusion, we were wrong here. We should highlight the trace entry that is before the last one. In this case, it will always point to a Sierra statement. Please make these changes, and the PR will be ready to merge.

[saimeunt]

@barabanovro thanks for the heads up, we should be getting there now 💪

[mazurroman]

lgtm!