feat(editor): indentation (#2174)

* switch to default codeblock tab handling

* feat(editor): indentation

apps/server/src/collaboration/collaboration.util.ts

@@ -34,6 +34,7 @@ import {
   Mention,
   Subpages,
   Highlight,
+  Indent,
   UniqueID,
   Columns,
   Column,
@@ -62,10 +63,11 @@ export const tiptapExtensions = [
   }),
   Heading,
   UniqueID.configure({
-    types: ['heading', 'paragraph'],
+    types: ['heading', 'paragraph', 'transclusionSource'],
   }),
   Comment,
   TextAlign.configure({ types: ['heading', 'paragraph'] }),
+  Indent,
   TaskList,
   TaskItem.configure({
     nested: true,

apps/server/src/common/helpers/prosemirror/indent-schema.spec.ts

@@ -0,0 +1,63 @@
+import { htmlToJson, jsonToHtml } from '../../../collaboration/collaboration.util';
+
+const findFirstChild = (
+  json: any,
+  type: string,
+): any | undefined => {
+  if (!json || typeof json !== 'object') return undefined;
+  if (json.type === type) return json;
+  if (Array.isArray(json.content)) {
+    for (const child of json.content) {
+      const found = findFirstChild(child, type);
+      if (found) return found;
+    }
+  }
+  return undefined;
+};
+
+describe('indent attribute round-trip', () => {
+  it('parses data-indent on a paragraph into the indent attribute', () => {
+    const html = '<p data-indent="3">Hello</p>';
+    const json = htmlToJson(html);
+    const paragraph = findFirstChild(json, 'paragraph');
+    expect(paragraph).toBeDefined();
+    expect(paragraph.attrs.indent).toBe(3);
+  });
+
+  it('parses data-indent on a heading into the indent attribute', () => {
+    const html = '<h2 data-indent="2">Heading</h2>';
+    const json = htmlToJson(html);
+    const heading = findFirstChild(json, 'heading');
+    expect(heading).toBeDefined();
+    expect(heading.attrs.indent).toBe(2);
+    expect(heading.attrs.level).toBe(2);
+  });
+
+  it('clamps out-of-range data-indent values', () => {
+    const html = '<p data-indent="42">Too deep</p>';
+    const json = htmlToJson(html);
+    const paragraph = findFirstChild(json, 'paragraph');
+    expect(paragraph.attrs.indent).toBe(8);
+  });
+
+  it('renders nonzero indent back to data-indent on HTML serialization', () => {
+    const html = '<p data-indent="4">Round-trip</p>';
+    const json = htmlToJson(html);
+    const out = jsonToHtml(json);
+    expect(out).toContain('data-indent="4"');
+  });
+
+  it('omits data-indent for indent zero', () => {
+    const html = '<p>No indent</p>';
+    const json = htmlToJson(html);
+    const out = jsonToHtml(json);
+    expect(out).not.toContain('data-indent');
+  });
+
+  it('preserves indent through HTML → JSON → HTML', () => {
+    const original = '<p data-indent="5">Five deep</p>';
+    const json = htmlToJson(original);
+    const final = jsonToHtml(json);
+    expect(final).toContain('data-indent="5"');
+  });
+});