diff --git a/src/json-crdt/__demos__/events-level1.ts b/src/json-crdt/__demos__/events-level1.ts
index ff4e33950d..420e540d4c 100644
--- a/src/json-crdt/__demos__/events-level1.ts
+++ b/src/json-crdt/__demos__/events-level1.ts
@@ -95,7 +95,7 @@ const main = async () => {
   console.log('Executing: model.applyPatch(patch)');
   console.log('');
   model.applyPatch(patch);
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -106,7 +106,7 @@ const main = async () => {
   console.log('Executing: model.reset(model0)');
   console.log('');
   model.reset(model0);
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -117,7 +117,7 @@ const main = async () => {
   console.log('Executing: model.api.root(456)');
   console.log('');
   model.api.root(456);
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -133,7 +133,7 @@ const main = async () => {
       a: 'b',
     });
   });
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
diff --git a/src/json-crdt/__demos__/events-level2-arr.ts b/src/json-crdt/__demos__/events-level2-arr.ts
index 61882237c8..755a9753f1 100644
--- a/src/json-crdt/__demos__/events-level2-arr.ts
+++ b/src/json-crdt/__demos__/events-level2-arr.ts
@@ -20,8 +20,8 @@ const main = async () => {
     my: {
       deep: {
         arr: [],
-      }
-    }
+      },
+    },
   });
 
   // Print out the document state.
@@ -39,7 +39,7 @@ const main = async () => {
   console.log('Changes which result in view change:');
   console.log('');
   model.api.arr(['my', 'deep', 'arr']).ins(0, [1, 2, 3]);
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -55,7 +55,7 @@ const main = async () => {
   //     .del(1, 1)
   //     .ins(1, [konst(2)]);
   // });
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -66,11 +66,12 @@ const main = async () => {
   console.log('More changes which result in only model change:');
   console.log('');
   // model.api.transaction(() => {
-    model.api.arr(['my', 'deep', 'arr'])
-      .del(1, 1)
-      .ins(1, [konst(2)]);
+  model.api
+    .arr(['my', 'deep', 'arr'])
+    .del(1, 1)
+    .ins(1, [konst(2)]);
   // });
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
diff --git a/src/json-crdt/__demos__/events-level2-obj.ts b/src/json-crdt/__demos__/events-level2-obj.ts
index 707b98a92c..e0f43fd9b0 100644
--- a/src/json-crdt/__demos__/events-level2-obj.ts
+++ b/src/json-crdt/__demos__/events-level2-obj.ts
@@ -20,8 +20,8 @@ const main = async () => {
     my: {
       deep: {
         obj: {},
-      }
-    }
+      },
+    },
   });
 
   // Print out the document state.
@@ -39,7 +39,7 @@ const main = async () => {
   console.log('Changes which result in view change:');
   console.log('');
   model.api.obj(['my', 'deep', 'obj']).set({foo: 'bar'});
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
@@ -50,7 +50,7 @@ const main = async () => {
   console.log('Changes which result in only model change:');
   console.log('');
   model.api.obj(['my', 'deep', 'obj']).set({foo: konst('bar')});
-  await new Promise(r => setTimeout(r, 1));
+  await new Promise((r) => setTimeout(r, 1));
   console.log('');
 
   // Print out the document state.
diff --git a/src/json-crdt/model/api/__tests__/ArrayApi.spec.ts b/src/json-crdt/model/api/__tests__/ArrayApi.spec.ts
index f3d673002b..570081f5f9 100644
--- a/src/json-crdt/model/api/__tests__/ArrayApi.spec.ts
+++ b/src/json-crdt/model/api/__tests__/ArrayApi.spec.ts
@@ -30,12 +30,12 @@ describe('events', () => {
       myArr: [1, 2, 3],
     });
     const events: any[] = [];
-    doc.api.arr(['myArr']).events.onViewChanges.listen(data => {
+    doc.api.arr(['myArr']).events.onViewChanges.listen((data) => {
       events.push(data);
     });
     expect(events.length).toBe(0);
     doc.api.arr(['myArr']).del(1, 1);
-    await new Promise(r => setTimeout(r, 1));
+    await new Promise((r) => setTimeout(r, 1));
     expect(events.length).toBe(1);
   });
 
@@ -45,18 +45,18 @@ describe('events', () => {
       myArr: [1, 2, 3],
     });
     const events: any[] = [];
-    doc.api.arr(['myArr']).events.onViewChanges.listen(data => {
+    doc.api.arr(['myArr']).events.onViewChanges.listen((data) => {
       events.push(data);
     });
-    await new Promise(r => setTimeout(r, 1));
+    await new Promise((r) => setTimeout(r, 1));
     expect(events.length).toBe(0);
     doc.api.arr(['myArr']).del(1, 1);
     doc.api.arr(['myArr']).ins(1, [konst(2)]);
-    await new Promise(r => setTimeout(r, 1));
+    await new Promise((r) => setTimeout(r, 1));
     expect(events.length).toBe(0);
     doc.api.arr(['myArr']).del(1, 1);
     doc.api.arr(['myArr']).ins(1, [2]);
-    await new Promise(r => setTimeout(r, 1));
+    await new Promise((r) => setTimeout(r, 1));
     expect(events.length).toBe(0);
   });
-});
\ No newline at end of file
+});