fix #481 - calculate path correctly when parents are moved

src/utils/YEvent.js

@@ -8,6 +8,7 @@ import {
 import * as set from 'lib0/set'
 import * as array from 'lib0/array'
 import { addsStruct } from './Transaction.js'
+import { ListCursor } from './ListCursor.js'
 
 /**
  * YEvent describes the changes on a YType.
@@ -62,7 +63,7 @@ export class YEvent {
    */
   get path () {
     // @ts-ignore _item is defined because target is integrated
-    return getPathTo(this.currentTarget, this.target)
+    return getPathTo(this.currentTarget, this.target, this.transaction)
   }
 
   /**
@@ -297,12 +298,13 @@ export class YEvent {
  *
  * @param {AbstractType<any>} parent
  * @param {AbstractType<any>} child target
+ * @param {Transaction} tr
  * @return {Array<string|number>} Path to the target
  *
  * @private
  * @function
  */
-const getPathTo = (parent, child) => {
+const getPathTo = (parent, child, tr) => {
   const path = []
   while (child._item !== null && child !== parent) {
     if (child._item.parentSub !== null) {
@@ -310,15 +312,11 @@ const getPathTo = (parent, child) => {
       path.unshift(child._item.parentSub)
     } else {
       // parent is array-ish
-      let i = 0
-      let c = /** @type {AbstractType<any>} */ (child._item.parent)._start
-      while (c !== child._item && c !== null) {
-        if (!c.deleted) {
-          i++
-        }
-        c = c.right
+      const c = new ListCursor(/** @type {AbstractType<any>} */ (child._item.parent))
+      while (c.nextItem != null && !c.reachedEnd && c.nextItem !== child._item) {
+        c.forward(tr, (c.nextItem.countable && !c.nextItem.deleted) ? c.nextItem.length : 0, true)
       }
-      path.unshift(i)
+      path.unshift(c.index)
     }
     child = /** @type {AbstractType<any>} */ (child._item.parent)
   }

tests/y-array.tests.js

@@ -1,10 +1,56 @@
-import { init, compare, applyRandomTests, Doc, AbstractType, TestConnector, Item } from './testHelper.js' // eslint-disable-line
+import { init, compare, applyRandomTests, Doc, Item } from './testHelper.js' // eslint-disable-line
 
 import * as Y from '../src/index.js'
 import * as t from 'lib0/testing'
 import * as prng from 'lib0/prng'
 import * as math from 'lib0/math'
 
+/**
+ * path should be correct when moving item - see yjs#481
+ *
+ * @param {t.TestCase} tc
+ */
+export const testArrayMovePathIssue481 = tc => {
+  const { users, testConnector, array0, array1 } = init(tc, { users: 2 })
+  array0.observeDeep(events => {
+    events.forEach(event => {
+      if (event.path.length > 0) {
+        /**
+         * @type {any}
+         */
+        let target = event.currentTarget
+        event.path.forEach(p => {
+          target = target.get(p)
+        })
+        t.assert(target === event.target)
+      }
+    })
+  })
+  array0.push([
+    ['a', '1.1'],
+    ['b', '2.2'],
+    ['c', '3.1'],
+    ['d', '4.1'],
+    ['e', '5.1']
+  ].map(e => Y.Array.from(e)))
+  testConnector.flushAllMessages()
+  users[1].transact(() => {
+    array1.get(1).insert(0, ['0'])
+    array1.move(1, 0)
+  })
+  testConnector.flushAllMessages()
+  users[1].transact(() => {
+    array1.get(3).insert(0, ['1'])
+    array1.move(3, 4)
+  })
+  testConnector.flushAllMessages()
+  users[1].transact(() => {
+    array1.get(2).insert(0, ['2'])
+    array1.move(2, array1.length)
+  })
+  testConnector.flushAllMessages()
+}
+
 /**
  * foreach has correct index - see yjs#485
  *