diff --git a/crates/loro-wasm/src/lib.rs b/crates/loro-wasm/src/lib.rs
index e9768b39..166110d5 100644
--- a/crates/loro-wasm/src/lib.rs
+++ b/crates/loro-wasm/src/lib.rs
@@ -674,8 +674,8 @@ impl Loro {
         let observer = observer::Observer::new(f);
         self.0
             .subscribe_root(Arc::new(move |e| {
-                // call_after_micro_task(observer.clone(), e)
-                call_subscriber(observer.clone(), e);
+                call_after_micro_task(observer.clone(), e)
+                // call_subscriber(observer.clone(), e);
             }))
             .into_u32()
     }
diff --git a/loro-js/tests/event.test.ts b/loro-js/tests/event.test.ts
index 090afd7f..6b83514f 100644
--- a/loro-js/tests/event.test.ts
+++ b/loro-js/tests/event.test.ts
@@ -21,6 +21,7 @@ describe("event", () => {
     const id = text.id;
     text.insert(0, "123");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.target).toEqual(id);
   });
 
@@ -41,14 +42,18 @@ describe("event", () => {
     const map = loro.getMap("map");
     map.set("0", 100);
     loro.commit();
+    await oneMs();
     expect(uniqueEvent).toBe(1);
     const bDoc = new Loro();
     bDoc.getText("text").insert(0, "1");
     bDoc.getText("text").insert(1, "1");
     bDoc.commit();
+    await oneMs();
     bDoc.getMap("map").set("0", "1");
     bDoc.commit();
+    await oneMs();
     loro.import(bDoc.exportFrom());
+    await oneMs();
     expect(uniqueEvent).toBe(2);
   });
 
@@ -62,14 +67,17 @@ describe("event", () => {
     const subMap = map.setContainer("sub", "Map");
     subMap.set("0", "1");
     loro.commit();
+    await oneMs();
 
     expect(lastEvent?.path).toStrictEqual(["map", "sub"]);
     const list = subMap.setContainer("list", "List");
     list.insert(0, "2");
     const text = list.insertContainer(1, "Text");
     loro.commit();
+    await oneMs();
     text.insert(0, "3");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.path).toStrictEqual(["map", "sub", "list", 1]);
   });
 
@@ -82,12 +90,14 @@ describe("event", () => {
     const text = loro.getText("t");
     text.insert(0, "3");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "text",
       diff: [{ insert: "3" }],
     } as TextDiff);
     text.insert(1, "12");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "text",
       diff: [{ retain: 1 }, { insert: "12" }],
@@ -103,12 +113,14 @@ describe("event", () => {
     const text = loro.getList("l");
     text.insert(0, "3");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "list",
       diff: [{ insert: ["3"] }],
     } as ListDiff);
     text.insert(1, "12");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "list",
       diff: [{ retain: 1 }, { insert: ["12"] }],
@@ -125,6 +137,7 @@ describe("event", () => {
     map.set("0", "3");
     map.set("1", "2");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "map",
       updated: {
@@ -135,6 +148,7 @@ describe("event", () => {
     map.set("0", "0");
     map.set("1", "1");
     loro.commit();
+    await oneMs();
     expect(lastEvent?.diff).toStrictEqual({
       type: "map",
       updated: {
@@ -161,8 +175,10 @@ describe("event", () => {
 
       text.insert(0, "123");
       loro.commit();
+      await oneMs();
       text.insert(1, "456");
       loro.commit();
+      await oneMs();
       expect(ran).toBeTruthy();
       // subscribeOnce test
       expect(text.toString()).toEqual("145623");
@@ -172,6 +188,7 @@ describe("event", () => {
       text.unsubscribe(loro, sub);
       text.insert(0, "789");
       loro.commit();
+      await oneMs();
       expect(ran).toBe(oldRan);
     });
 
@@ -185,18 +202,22 @@ describe("event", () => {
 
       const subMap = map.setContainer("sub", "Map");
       loro.commit();
+      await oneMs();
       expect(times).toBe(1);
       const text = subMap.setContainer("k", "Text");
       loro.commit();
+      await oneMs();
       expect(times).toBe(2);
       text.insert(0, "123");
       loro.commit();
+      await oneMs();
       expect(times).toBe(3);
 
       // unsubscribe
       loro.unsubscribe(sub);
       text.insert(0, "123");
       loro.commit();
+      await oneMs();
       expect(times).toBe(3);
     });
 
@@ -210,8 +231,10 @@ describe("event", () => {
 
       const text = list.insertContainer(0, "Text");
       loro.commit();
+      await oneMs();
       expect(times).toBe(1);
       text.insert(0, "123");
+      await oneMs();
       loro.commit();
       expect(times).toBe(2);
 
@@ -219,6 +242,7 @@ describe("event", () => {
       loro.unsubscribe(sub);
       text.insert(0, "123");
       loro.commit();
+      await oneMs();
       expect(times).toBe(2);
     });
   });
@@ -250,23 +274,27 @@ describe("event", () => {
       });
       text.insert(0, "你好");
       loro.commit();
+      await oneMs();
       expect(text.toString()).toBe(string);
 
       text.insert(1, "世界");
       loro.commit();
+      await oneMs();
       expect(text.toString()).toBe(string);
 
       text.insert(2, "👍");
       loro.commit();
+      await oneMs();
       expect(text.toString()).toBe(string);
 
       text.insert(2, "♪(^∇^*)");
       loro.commit();
+      await oneMs();
       expect(text.toString()).toBe(string);
     });
   });
 });
 
-function zeroMs(): Promise<void> {
+function oneMs(): Promise<void> {
   return new Promise((r) => setTimeout(r));
 }
diff --git a/loro-js/tests/misc.test.ts b/loro-js/tests/misc.test.ts
index 00cccd3d..75da4fc5 100644
--- a/loro-js/tests/misc.test.ts
+++ b/loro-js/tests/misc.test.ts
@@ -31,6 +31,7 @@ describe("transaction", () => {
     text.insert(0, "hello world");
     assertEquals(count, 0);
     loro.commit();
+    await one_ms();
     assertEquals(count, 1);
   });
 
@@ -50,6 +51,7 @@ describe("transaction", () => {
     text.insert(0, "hello world");
     assertEquals(count, 0);
     loro.commit("origin");
+    await one_ms();
     assertEquals(count, 1);
   });
 });
@@ -73,14 +75,17 @@ describe("subscribe", () => {
 
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
 
     assertEquals(count, 2);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
     assertEquals(count, 3);
     loro.unsubscribe(sub);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
     assertEquals(count, 3);
   });
 
@@ -95,10 +100,12 @@ describe("subscribe", () => {
     assertEquals(count, 0);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
 
     assertEquals(count, 1);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
 
     assertEquals(count, 1);
   });
@@ -112,13 +119,16 @@ describe("subscribe", () => {
     });
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
     assertEquals(count, 1);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
     assertEquals(count, 2);
     loro.unsubscribe(sub);
     text.insert(0, "hello world");
     loro.commit();
+    await one_ms();
     assertEquals(count, 2);
   });
 });
@@ -147,6 +157,7 @@ describe("sync", () => {
     const bText = b.getText("text");
     aText.insert(0, "abc");
     a.commit();
+    await one_ms();
 
     assertEquals(aText.toString(), bText.toString());
   });