add merge tests for #263

src/index.js

@@ -72,5 +72,6 @@ export {
   tryGc,
   transact,
   AbstractConnector,
-  logType
+  logType,
+  mergeUpdates
 } from './internals.js'

src/internals.js

@@ -15,6 +15,7 @@ export * from './utils/Snapshot.js'
 export * from './utils/StructStore.js'
 export * from './utils/Transaction.js'
 export * from './utils/UndoManager.js'
+export * from './utils/updates.js'
 export * from './utils/YEvent.js'
 
 export * from './types/AbstractType.js'

src/utils/updates.js

@@ -0,0 +1,16 @@
+
+/**
+ * @param {Array<Uint8Array>} updates
+ * @return {Uint8Array}
+ */
+export const mergeUpdates = updates => {
+  return updates[0]
+}
+
+/**
+ * @param {Uint8Array} update
+ * @param {Uint8Array} sv
+ */
+export const diffUpdate = (update, sv) => {
+  return update
+}

tests/index.js

@@ -8,6 +8,7 @@ import * as undoredo from './undo-redo.tests.js'
 import * as compatibility from './compatibility.tests.js'
 import * as doc from './doc.tests.js'
 import * as snapshot from './snapshot.tests.js'
+import * as updates from './updates.tests.js'
 
 import { runTests } from 'lib0/testing.js'
 import { isBrowser, isNode } from 'lib0/environment.js'
@@ -17,7 +18,7 @@ if (isBrowser) {
   log.createVConsole(document.body)
 }
 runTests({
-  doc, map, array, text, xml, encoding, undoredo, compatibility, snapshot
+  doc, map, array, text, xml, encoding, undoredo, compatibility, snapshot, updates
 }).then(success => {
   /* istanbul ignore next */
   if (isNode) {

tests/updates.tests.js

@@ -0,0 +1,64 @@
+import * as t from 'lib0/testing.js'
+import { init, compare } from './testHelper.js' // eslint-disable-line
+import * as Y from '../src/index.js'
+
+/**
+ * @param {Array<Y.Doc>} users
+ */
+const fromUpdates = users => {
+  const updates = users.map(user =>
+    Y.encodeStateAsUpdate(user)
+  )
+  const ydoc = new Y.Doc()
+  Y.applyUpdate(ydoc, Y.mergeUpdates(updates))
+  return ydoc
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergeUpdates = tc => {
+  const { users, array0, array1 } = init(tc, { users: 3 })
+
+  array0.insert(0, [1])
+  array1.insert(0, [2])
+
+  const merged = fromUpdates(users)
+  compare(users)
+  t.compareArrays(array0.toArray(), merged.getArray('array').toArray())
+}
+
+/**
+ * @param {t.TestCase} tc
+ */
+export const testMergeUpdatesWrongOrder = tc => {
+  const ydoc = new Y.Doc()
+  const updates = /** @type {Array<Uint8Array>} */ ([])
+  ydoc.on('update', update => { updates.push(update) })
+
+  const array = ydoc.getArray()
+  array.insert(0, [1])
+  array.insert(0, [2])
+  array.insert(0, [3])
+  array.insert(0, [4])
+
+  const wrongOrder = Y.mergeUpdates([
+    Y.mergeUpdates(updates.slice(2)),
+    Y.mergeUpdates(updates.slice(0, 2))
+  ])
+  const overlapping = Y.mergeUpdates([
+    Y.mergeUpdates(updates.slice(2)),
+    Y.mergeUpdates(updates.slice(1, 3)),
+    updates[0]
+  ])
+  const separated = Y.mergeUpdates([
+    Y.mergeUpdates([updates[0], updates[2]]),
+    Y.mergeUpdates([updates[1], updates[3]])
+  ])
+
+  ;[wrongOrder, overlapping, separated].forEach(updates => {
+    const merged = new Y.Doc()
+    Y.applyUpdate(merged, updates)
+    t.compareArrays(merged.getArray().toArray(), array.toArray())
+  })
+}