fix setContents on block embed ending

core/quill.js

@@ -383,18 +383,13 @@ class Quill {
       () => {
         delta = new Delta(delta);
         const length = this.getLength();
-        const deleted = this.editor.deleteText(0, length);
+        // Quill will set empty editor to \n
+        const delete1 = this.editor.deleteText(0, length);
+        // delta always applied before existing content
         const applied = this.editor.applyDelta(delta);
-        const lastOp = applied.ops[applied.ops.length - 1];
-        if (
-          lastOp != null &&
-          typeof lastOp.insert === 'string' &&
-          lastOp.insert[lastOp.insert.length - 1] === '\n'
-        ) {
-          this.editor.deleteText(this.getLength() - 1, 1);
-          applied.delete(1);
-        }
-        return deleted.compose(applied);
+        // Remove extra \n from empty editor initialization
+        const delete2 = this.editor.deleteText(this.getLength() - 1, 1);
+        return delete1.compose(applied).compose(delete2);
       },
       source,
     );

test/unit/core/quill.js

@@ -429,6 +429,13 @@ describe('Quill', function() {
       expect(quill.getContents()).toEqual(contents);
       expect(delta).toEqual(contents.delete(contents.length()));
     });
+
+    it('block embed', function() {
+      const quill = this.initialize(Quill, '<p>Hello World!</p>');
+      const contents = new Delta().insert({ video: '#' });
+      quill.setContents(contents);
+      expect(quill.getContents()).toEqual(contents);
+    });
   });
 
   describe('setText()', function() {