Make positions possibly negatives (#5690)

Closes https://github.com/twentyhq/twenty/issues/5427

packages/twenty-front/src/modules/object-record/record-board/components/RecordBoard.tsx

@@ -9,6 +9,7 @@ import { useRecordBoardStates } from '@/object-record/record-board/hooks/interna
 import { useRecordBoardSelection } from '@/object-record/record-board/hooks/useRecordBoardSelection';
 import { RecordBoardColumn } from '@/object-record/record-board/record-board-column/components/RecordBoardColumn';
 import { RecordBoardScope } from '@/object-record/record-board/scopes/RecordBoardScope';
+import { getDraggedRecordPosition } from '@/object-record/record-board/utils/get-dragged-record-position.util';
 import { recordStoreFamilyState } from '@/object-record/record-store/states/recordStoreFamilyState';
 import { TableHotkeyScope } from '@/object-record/record-table/types/TableHotkeyScope';
 import { DragSelect } from '@/ui/utilities/drag-select/components/DragSelect';
@@ -107,7 +108,6 @@ export const RecordBoard = ({ recordBoardId }: RecordBoardProps) => {
               .getLoadable(recordStoreFamilyState(recordBeforeId))
               .getValue()
           : null;
-        const recordBeforePosition: number | undefined = recordBefore?.position;
 
         const recordAfterId =
           otherRecordsInDestinationColumn[destinationIndexInColumn];
@@ -116,12 +116,11 @@ export const RecordBoard = ({ recordBoardId }: RecordBoardProps) => {
               .getLoadable(recordStoreFamilyState(recordAfterId))
               .getValue()
           : null;
-        const recordAfterPosition: number | undefined = recordAfter?.position;
 
-        const beforeBoundary = recordBeforePosition ?? 0;
-        const afterBoundary = recordAfterPosition ?? beforeBoundary + 1;
-
-        const draggedRecordPosition = (beforeBoundary + afterBoundary) / 2;
+        const draggedRecordPosition = getDraggedRecordPosition(
+          recordBefore?.position,
+          recordAfter?.position,
+        );
 
         updateOneRecord({
           idToUpdate: draggedRecordId,

packages/twenty-front/src/modules/object-record/record-board/utils/__tests__/get-dragged-record-position.util.test.ts

@@ -0,0 +1,27 @@
+import { getDraggedRecordPosition } from '../get-dragged-record-position.util';
+
+describe('getDraggedRecordPosition', () => {
+  it('when both records defined and positive, should return the average of the two positions', () => {
+    expect(getDraggedRecordPosition(1, 3)).toBe(2);
+  });
+
+  it('when both records defined and negative, should return the average of the two positions', () => {
+    expect(getDraggedRecordPosition(-3, -1)).toBe(-2);
+  });
+
+  it('when both records defined and one negative, should return the average of the two positions', () => {
+    expect(getDraggedRecordPosition(-1, 3)).toBe(1);
+  });
+
+  it('when only record after, should return the position - 1', () => {
+    expect(getDraggedRecordPosition(undefined, 3)).toBe(2);
+  });
+
+  it('when only record before, should return the position + 1', () => {
+    expect(getDraggedRecordPosition(1, undefined)).toBe(2);
+  });
+
+  it('when both records undefined, should return 1', () => {
+    expect(getDraggedRecordPosition(undefined, undefined)).toBe(1);
+  });
+});

packages/twenty-front/src/modules/object-record/record-board/utils/get-dragged-record-position.util.ts

@@ -0,0 +1,16 @@
+import { isDefined } from '~/utils/isDefined';
+
+export const getDraggedRecordPosition = (
+  recordBeforePosition?: number,
+  recordAfterPosition?: number,
+): number => {
+  if (isDefined(recordAfterPosition) && isDefined(recordBeforePosition)) {
+    return (recordBeforePosition + recordAfterPosition) / 2;
+  } else if (isDefined(recordAfterPosition)) {
+    return recordAfterPosition - 1;
+  } else if (isDefined(recordBeforePosition)) {
+    return recordBeforePosition + 1;
+  } else {
+    return 1;
+  }
+};