Fix uncategorize undo save error

src/actions/__tests__/uncategorize.ts

@@ -109,6 +109,31 @@ describe('normal view', () => {
     expectPathToEqual(stateNew, stateNew.cursor, ['a', 'c'])
   })
 
+  it('does not merge a child into the category being uncategorized', () => {
+    const steps = [
+      importText({
+        text: `
+          - a
+            - b
+              - b
+                - c
+        `,
+      }),
+      setCursor(['a', 'b']),
+      uncategorize({}),
+    ]
+
+    const stateNew = reducerFlow(steps)(initialState())
+    const exported = exportContext(stateNew, [HOME_TOKEN], 'text/plain')
+
+    expect(exported).toBe(`- ${HOME_TOKEN}
+  - a
+    - b
+      - c`)
+
+    expectPathToEqual(stateNew, stateNew.cursor, ['a', 'b'])
+  })
+
   it('after uncategorize context set cursor to the first visible children.', () => {
     const steps = [
       newThought('a'),

src/actions/uncategorize.ts

@@ -16,13 +16,11 @@ import rootedParentOf from '../selectors/rootedParentOf'
 import simplifyPath from '../selectors/simplifyPath'
 import { registerActionMetadata } from '../util/actionMetadata.registry'
 import appendToPath from '../util/appendToPath'
-import createId from '../util/createId'
 import head from '../util/head'
 import isAttribute from '../util/isAttribute'
 import parentOf from '../util/parentOf'
 import reducerFlow from '../util/reducerFlow'
 import deleteThought from './deleteThought'
-import editThought from './editThought'
 import sort from './sort'
 
 interface Options {
@@ -105,14 +103,6 @@ const uncategorize = (state: State, { at }: Options): State => {
   }
 
   return reducerFlow([
-    // first edit the unacategorized thought to a unique value
-    // otherwise, it could get merged when children are outdented in the next step
-    editThought({
-      oldValue: thought.value,
-      newValue: createId(), // unique value
-      path: simplePath,
-    }),
-
     // Sort parent context if sort preference exists and parent does not have a sort preference
     // Sort preference must be moved up before sort to prevent conversion to manual sort.
     contextHasSortPreference && !parentHasSortPreference
@@ -135,6 +125,8 @@ const uncategorize = (state: State, { at }: Options): State => {
         oldPath: appendToPath(simplePath, child.id),
         newPath: appendToPath(parentOf(simplePath), child.id),
         newRank: getNewRank(state, child),
+        // If a child has the same value as the category being deleted, do not merge it into the category.
+        skipMerge: child.value === thought.value,
       })
     }),
 

src/commands/__tests__/uncategorize.ts

@@ -1,16 +1,80 @@
 import { importTextActionCreator as importText } from '../../actions/importText'
+import { undoActionCreator as undo } from '../../actions/undo'
 import { executeCommandWithMulticursor } from '../../commands'
 import { HOME_TOKEN } from '../../constants'
+import { initialize } from '../../initialize'
 import exportContext from '../../selectors/exportContext'
 import store from '../../stores/app'
 import { addMulticursorAtFirstMatchActionCreator as addMulticursor } from '../../test-helpers/addMulticursorAtFirstMatch'
+import expectPathToEqual from '../../test-helpers/expectPathToEqual'
 import initStore from '../../test-helpers/initStore'
 import { setCursorFirstMatchActionCreator as setCursor } from '../../test-helpers/setCursorFirstMatch'
 import uncategorizeCommand from '../uncategorize'
 
 beforeEach(initStore)
 
 describe('uncategorize', () => {
+  it('undoes uncategorize of a duplicate uncle', () => {
+    store.dispatch([
+      importText({
+        text: `
+          - a
+          - b
+            - a
+              - c
+        `,
+      }),
+      setCursor(['b', 'a']),
+    ])
+
+    executeCommandWithMulticursor(uncategorizeCommand, { store })
+
+    let state = store.getState()
+    expect(exportContext(state, [HOME_TOKEN], 'text/plain')).toEqual(`- ${HOME_TOKEN}
+  - a
+  - b
+    - c`)
+    expectPathToEqual(state, state.cursor, ['b', 'c'])
+
+    expect(() => store.dispatch(undo())).not.toThrow()
+
+    state = store.getState()
+    expect(exportContext(state, [HOME_TOKEN], 'text/plain')).toEqual(`- ${HOME_TOKEN}
+  - a
+  - b
+    - a
+      - c`)
+    expectPathToEqual(state, state.cursor, ['b', 'a'])
+  })
+
+  it('persists undoing uncategorize of a duplicate uncle without a save error', async () => {
+    const { cleanup } = await initialize()
+
+    try {
+      store.dispatch([
+        importText({
+          text: `
+            - a
+            - b
+              - a
+                - c
+          `,
+        }),
+        setCursor(['b', 'a']),
+      ])
+
+      executeCommandWithMulticursor(uncategorizeCommand, { store })
+      store.dispatch(undo())
+
+      await vi.runOnlyPendingTimersAsync()
+      await Promise.resolve()
+
+      expect(store.getState().error).toBeNull()
+    } finally {
+      cleanup()
+    }
+  }, 10000)
+
   describe('multicursor', () => {
     it('collapses multiple thoughts', async () => {
       store.dispatch([

src/redux-enhancers/undoRedoEnhancer.ts

@@ -68,11 +68,12 @@ const restorePushQueueFromPatches = (state: State, oldState: State, patch: Patch
   const lexemeIndexChanges = patch.filter(p => p?.path.startsWith('/thoughts/lexemeIndex/'))
   const thoughtIndexChanges = patch.filter(p => p?.path.startsWith('/thoughts/thoughtIndex/'))
 
-  const lexemeIndexUpdates = lexemeIndexChanges.reduce<Index<Lexeme | null>>((acc, op) => {
-    const lexemeKey = op.path.slice('/thoughts/lexemeIndex/'.length).split('/')[0]
+  const lexemeIndexUpdates = lexemeIndexChanges.reduce<Index<Lexeme | null>>((acc, { path }) => {
+    const lexemeKey = path.slice('/thoughts/lexemeIndex/'.length).split('/')[0]
     return {
       ...acc,
-      [lexemeKey]: op.value || null,
+      // Patch paths may target nested lexeme properties such as contexts. Persist the full lexeme.
+      [lexemeKey]: state.thoughts.lexemeIndex[lexemeKey] || null,
     }
   }, {})
   const thoughtIndexUpdates = thoughtIndexChanges.reduce((acc, { path }) => {