refactor: consolidate vault ordering

src/utils/vaultOrdering.test.ts

@@ -1,6 +1,6 @@
 import { describe, expect, it } from 'vitest'
 import type { VaultOption } from '../components/status-bar/types'
-import { canMoveVaultPath, moveVaultPath, orderVaultsByPath } from './vaultOrdering'
+import { canMoveVaultPath, moveVaultPath, orderVaultsByPath, reorderVaultPath, vaultPathList } from './vaultOrdering'
 
 const vaults: VaultOption[] = [
   { label: 'Laputa', path: '/laputa' },
@@ -9,6 +9,10 @@ const vaults: VaultOption[] = [
 ]
 
 describe('vaultOrdering', () => {
+  it('extracts vault paths in display order', () => {
+    expect(vaultPathList(vaults)).toEqual(['/laputa', '/research', '/archive'])
+  })
+
   it('orders vaults by a complete path list', () => {
     expect(orderVaultsByPath(vaults, ['/archive', '/laputa', '/research'])).toEqual([
       vaults[2],
@@ -27,6 +31,17 @@ describe('vaultOrdering', () => {
     expect(moveVaultPath(vaults, '/research', 'down')).toEqual(['/laputa', '/archive', '/research'])
   })
 
+  it('reorders a dragged vault path to the hovered path index', () => {
+    expect(reorderVaultPath(vaults, '/laputa', '/archive')).toEqual(['/research', '/archive', '/laputa'])
+    expect(reorderVaultPath(vaults, '/archive', '/laputa')).toEqual(['/archive', '/laputa', '/research'])
+  })
+
+  it('ignores no-op or unknown drag reorder paths', () => {
+    expect(reorderVaultPath(vaults, '/research', '/research')).toBeNull()
+    expect(reorderVaultPath(vaults, '/missing', '/archive')).toBeNull()
+    expect(reorderVaultPath(vaults, '/archive', '/missing')).toBeNull()
+  })
+
   it('reports whether a vault can move in a direction', () => {
     expect(canMoveVaultPath(vaults, '/laputa', 'up')).toBe(false)
     expect(canMoveVaultPath(vaults, '/laputa', 'down')).toBe(true)

src/utils/vaultOrdering.ts

@@ -2,7 +2,7 @@ import type { VaultOption } from '../components/status-bar/types'
 
 export type VaultMoveDirection = 'up' | 'down'
 
-function vaultPathList(vaults: VaultOption[]): string[] {
+export function vaultPathList(vaults: VaultOption[]): string[] {
   return vaults.map((vault) => vault.path)
 }
 
@@ -35,6 +35,20 @@ export function moveVaultPath(vaults: VaultOption[], path: string, direction: Va
   return nextPaths
 }
 
+export function reorderVaultPath(vaults: VaultOption[], activePath: string, overPath: string): string[] | null {
+  if (activePath === overPath) return null
+
+  const orderedPaths = vaultPathList(vaults)
+  const activeIndex = orderedPaths.indexOf(activePath)
+  const overIndex = orderedPaths.indexOf(overPath)
+  if (activeIndex === -1 || overIndex === -1) return null
+
+  const nextPaths = [...orderedPaths]
+  const [movedPath] = nextPaths.splice(activeIndex, 1)
+  nextPaths.splice(overIndex, 0, movedPath)
+  return nextPaths
+}
+
 export function canMoveVaultPath(vaults: VaultOption[], path: string, direction: VaultMoveDirection): boolean {
   return moveVaultPath(vaults, path, direction) !== null
 }