From 04cff60931f331cda287cba0c0fc077be1ca49e5 Mon Sep 17 00:00:00 2001
From: Kevin Jahns <kevin.jahns@pm.me>
Date: Mon, 8 Feb 2021 13:46:22 +0100
Subject: [PATCH] add performance test for updates

---
 tests/y-text.tests.js | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/tests/y-text.tests.js b/tests/y-text.tests.js
index ad4fbc5d..dbb61457 100644
--- a/tests/y-text.tests.js
+++ b/tests/y-text.tests.js
@@ -368,6 +368,42 @@ export const testLargeFragmentedDocument = tc => {
   })()
 }
 
+/**
+ * @param {t.TestCase} tc
+ */
+export const testIncrementalUpdatesPerformanceOnLargeFragmentedDocument = tc => {
+  const itemsToInsert = largeDocumentSize
+  const updates = /** @type {Array<Uint8Array>} */ ([])
+  ;(() => {
+    const doc1 = new Y.Doc()
+    doc1.on('update', update => {
+      updates.push(update)
+    })
+    const text0 = doc1.getText('txt')
+    tryGc()
+    t.measureTime(`time to insert ${itemsToInsert} items`, () => {
+      doc1.transact(() => {
+        for (let i = 0; i < itemsToInsert; i++) {
+          text0.insert(0, '0')
+        }
+      })
+    })
+    tryGc()
+  })()
+  ;(() => {
+    t.measureTime(`time to merge ${itemsToInsert} updates (differential updates)`, () => {
+      Y.mergeUpdates(updates)
+    })
+    tryGc()
+    t.measureTime(`time to merge ${itemsToInsert} updates (ydoc updates)`, () => {
+      const ydoc = new Y.Doc()
+      updates.forEach(update => {
+        Y.applyUpdate(ydoc, update)
+      })
+    })
+  })()
+}
+
 /**
  * Splitting surrogates can lead to invalid encoded documents.
  *