There's a format we like to see for descriptions. They should always stand alone from the summary, wrap to <= 72 characters, and explain what problem needed solving, why, and how it was solved.
We use these directly for commit messages, so we have a writeup covering both:
https://www.notion.so/reviewboard/Writing-Good-Change-Descriptions-10529e7c207743fa8ca90153d4b21fea
The summary should ideally also explicitly mention "JavaScript extensions", and end with a period.

Unit tests for getFieldView and matchContains should be added to js/views/tests/reviewRequestEditorViewTests.js and listed in the Testing Done. This will be more useful to us than your extension's testing, because it'll ensure there won't be regressions, and is "proof" that this works as expected.
You can run the test suite by going to http://localhost:8080/js-tests/ (assuming usage of a dev server).

Should be "Return the view ..." and "ID".

This is missing a "Returns" section.

"ID"

While useful for JavaScript extensions, this change isn't extension-specific. It'd be better to word the summary and description to be more about the purpose of the method itself, leaving off the extensions parts.
Text also wraps a bit too short. ~72 characters would be best.

The tests in this file could use some cleanup, but would you mind making a top-level describe() for "Methods", and place this in there? The description should be the method name.

Ship It!