From b0b0ec35e345f6afb9eacc386fcc07e02bf3f964 Mon Sep 17 00:00:00 2001
From: d3m1d0v <d3m1d0v@yandex-team.ru>
Date: Thu, 25 Sep 2025 18:08:11 +0300
Subject: [PATCH] fix(BaseSchema): fix serialization of empty paragraphs inside
 other blocks

---
 .../base/BaseSchema/BaseSchema.test.ts        | 68 ++++++++++++++-----
 .../base/BaseSchema/BaseSchemaSpecs/index.ts  |  3 +-
 2 files changed, 53 insertions(+), 18 deletions(-)

diff --git a/src/extensions/base/BaseSchema/BaseSchema.test.ts b/src/extensions/base/BaseSchema/BaseSchema.test.ts
index 2c4aea1f8..763f8cf64 100644
--- a/src/extensions/base/BaseSchema/BaseSchema.test.ts
+++ b/src/extensions/base/BaseSchema/BaseSchema.test.ts
@@ -2,28 +2,62 @@ import {builders} from 'prosemirror-test-builder';
 
 import {createMarkupChecker} from '../../../../tests/sameMarkup';
 import {ExtensionsManager} from '../../../core';
+import {BlockquoteSpecs, blockquoteNodeName} from '../../markdown/Blockquote/BlockquoteSpecs';
 
 import {BaseNode, BaseSchemaSpecs} from './BaseSchemaSpecs';
 
-const {
-    schema,
-    markupParser: parser,
-    serializer,
-} = new ExtensionsManager({
-    extensions: (builder) => builder.use(BaseSchemaSpecs, {}),
-}).buildDeps();
-
-const {doc, p} = builders<'doc' | 'p'>(schema, {
-    doc: {nodeType: BaseNode.Doc},
-    p: {nodeType: BaseNode.Paragraph},
-});
+describe('BaseSchema extension', () => {
+    describe('common', () => {
+        const {
+            schema,
+            markupParser: parser,
+            serializer,
+        } = new ExtensionsManager({
+            extensions: (builder) => builder.use(BaseSchemaSpecs, {}),
+        }).buildDeps();
 
-const {same} = createMarkupChecker({parser, serializer});
+        const {doc, p} = builders<'doc' | 'p'>(schema, {
+            doc: {nodeType: BaseNode.Doc},
+            p: {nodeType: BaseNode.Paragraph},
+        });
 
-describe('BaseSchema extension', () => {
-    it('should parse a paragraph', () => same('hello!', doc(p('hello!'))));
+        const {same} = createMarkupChecker({parser, serializer});
+
+        it('should parse a paragraph', () => same('hello!', doc(p('hello!'))));
+
+        it('should parse a few paragraphs', () => {
+            same(['hello', '', 'world!'].join('\n'), doc(p('hello'), p('world!')));
+        });
+    });
+
+    describe('preserveEmptyRows=true', () => {
+        const {
+            schema,
+            markupParser: parser,
+            serializer,
+        } = new ExtensionsManager({
+            extensions: (builder) =>
+                builder.use(BaseSchemaSpecs, {preserveEmptyRows: true}).use(BlockquoteSpecs),
+        }).buildDeps();
+
+        const {doc, p, bq} = builders<'doc' | 'p' | 'bq'>(schema, {
+            doc: {nodeType: BaseNode.Doc},
+            p: {nodeType: BaseNode.Paragraph},
+            bq: {nodeType: blockquoteNodeName},
+        });
+
+        const {same} = createMarkupChecker({parser, serializer});
+
+        it('should serialize empty paragraph as &nbsp;', () =>
+            same(
+                'hello!\n\n&nbsp;\n\nworld!',
+                doc(p('hello!'), p(String.fromCharCode(160 /* &nbsp; */)), p('world!')),
+            ));
 
-    it('should parse a few paragraphs', () => {
-        same(['hello', '', 'world!'].join('\n'), doc(p('hello'), p('world!')));
+        it('should correct insert &nbsp; inside other nodes', () =>
+            same(
+                '> hello!\n>\n> &nbsp;\n> \n> world!',
+                doc(bq(p('hello!'), p(String.fromCharCode(160 /* &nbsp; */)), p('world!'))),
+            ));
     });
 });
diff --git a/src/extensions/base/BaseSchema/BaseSchemaSpecs/index.ts b/src/extensions/base/BaseSchema/BaseSchemaSpecs/index.ts
index f88bccdf2..d42fbb7ec 100644
--- a/src/extensions/base/BaseSchema/BaseSchemaSpecs/index.ts
+++ b/src/extensions/base/BaseSchema/BaseSchemaSpecs/index.ts
@@ -85,7 +85,8 @@ export const BaseSchemaSpecs: ExtensionAuto<BaseSchemaSpecsOptions> = (builder,
                     }
 
                     if (!isParentEmpty) {
-                        state.write('&nbsp;\n\n');
+                        state.write('&nbsp;\n');
+                        state.write('\n');
                     }
                 } else {
                     state.renderInline(node);