We have a working code block but it needs work before it can be released:

• Migrate to RichtText so it can have split detection
• Verify that pasting works. From First steps to implement pasting external content #553:

When multi-paragraph / image content is pasted into a code block, the block is not split, and new blocks are not created. Styled text (colored links) keep their color, and images are converted to an object replacement character (which renders as a little square).

Related issues:

#368 #469