Summary
According to Jest lcov reports shown on ci.blueocean.io (example from latest, code coverage as reported by Jest is low. As of this writing:

• Statements: 5%
• Branches: 4%
• Functions: 4%
• Lines: 10%

While it is generally understood that high code coverage numbers != test completeness, these numbers do seem low, especially when compared to other components in Blue Ocean.