# Introduction
Avoid having multiple `isDefined` definition across our pacakges
Also avoid importing `isDefined` from `twenty-ui` which exposes a huge
barrel for a such little util function
## In a nutshell
Removed own `isDefined.ts` definition from `twenty-ui` `twenty-front`
and `twenty-server` to move it to `twenty-shared`.
Updated imports for each packages, and added explicit dependencies to
`twenty-shared` if not already in place
Related PR https://github.com/twentyhq/twenty/pull/9941
This PR introduces many improvements over the new profiling story
feature, with new tests and some refactor with main :
- Added use-context-selector for getting value faster in display fields
and created useRecordFieldValue() hook and RecordValueSetterEffect to
synchronize states
- Added performance test command in CI
- Refactored ExpandableList drill-downs with FieldFocusContext
- Refactored field button icon logic into getFieldButtonIcon util
- Added RelationFieldDisplay perf story
- Added RecordTableCell perf story
- First split test of useField.. hook with useRelationFieldDisplay()
- Fixed problem with set cell soft focus
- Isolated logic between display / soft focus and edit mode in the
related components to optimize performances for display mode.
- Added warmupRound config for performance story decorator
- Added variance in test reporting
