Keep code review submit button disabled until there is text - #48069

We saw an issue where the submit button would sometimes get enabled even if there was no text in the comment box. This was due to the fact that when there's no text, the comment text value may still contain newline characters (either '\n' for only paragraph text or '```\n\n\n```\n' for code block markdown + paragraph). This adds a check which trims newlines to check if the comment contents are actually empty. Trying to save empty comments would result in a 404 anyway but this issue was causing some flakiness in UI tests.

Links

JIRA: https://codedotorg.atlassian.net/browse/JAVA-683

Testing story

Tested locally with empty text, newlines, and spaces.

Deployment strategy

Follow-up work

Privacy

Security

Caching

PR Checklist:

• Tests provide adequate coverage
• Privacy and Security impacts have been assessed
• Code is well-commented
• New features are translatable or updates will not break translations
• Relevant documentation has been added or updated
• User impact is well-understood and desirable
• Pull Request is labeled appropriately
• Follow-up work items (including potential tech debt) are tracked and linked