[Backend] Refactor ipynb kernel messages serialization

[senwang86]

Summary

Currently, the kernel messages are concatenated and stored in a single object, i.e., pod.result. This concatenation behavior creates a few discrepancy with Colab regarding the output results, e.g., it can't produce multiple plots in a single pod, the order of line execution might confuse users (see screenshots in Test section)

Test

Before

• 
• 

After

• Export/Import also verified

Follow-up

• The ResultBlock in Code.tsx needs more tuning
• We might need to support more message types, Messaging in Jupyter

[lihebi]

1. The stderr is not printed.
2. Also, I'd like to keep the visual <hr/> to visually separate the stdout/stderr-stream and the return value.

Reference:

Old behavior:

[lihebi]

1. The stderr is not printed.
2. Also, I'd like to keep the visual <hr/> to visually separate the stdout/stderr-stream and the return value.

What do you say about these two issues? @senwang86 The rest of the code looks good to me.

[senwang86]

1. The stderr is not printed.
2. Also, I'd like to keep the visual <hr/> to visually separate the stdout/stderr-stream and the return value.

What do you say about these two issues? @senwang86 The rest of the code looks good to me.

These 2 issues are addressed in the ab4818c, can you give it a test?

[lihebi]

Just tried, the order is not fixed. Two issues:

1. the order should be 1,2,3
2. there shouldn't be spaces in between (there are spaces after 3, and after 2)

[senwang86]

Just tried, the order is not fixed. Two issues:

1. the order should be 1,2,3
2. there shouldn't be spaces in between (there are spaces after 3, and after 2)

Forget to mention about this, it depends on how Ipynb kernel handles the running result, the result is consistent with Colab.

[lihebi]

I see, SG.

[senwang86]

I see, SG.

Spaces removed.

[lihebi]

Cool, thanks!