#8187 It is possible to create preset with empty name

packages/ketcher-core/__tests__/application/editor/Editor.test.ts

@@ -161,5 +161,38 @@ describe('CoreEditor', () => {
       );
       expect(editor.monomersLibrary.length).toBe(initialLibrarySize + 1);
     });
+
+    it('should reject monomer group template without name', () => {
+      const unnamedPreset = {
+        root: {
+          templates: [
+            {
+              $ref: 'monomerGroupTemplate-',
+            },
+          ],
+        },
+        'monomerGroupTemplate-': {
+          type: 'monomerGroupTemplate',
+          id: '',
+          name: '   ',
+          class: 'RNA',
+          templates: [],
+          connections: [],
+        },
+      };
+
+      const initialTemplatesCount =
+        editor.monomersLibraryParsedJson?.root.templates.length ?? 0;
+      editor.updateMonomersLibrary(JSON.stringify(unnamedPreset));
+
+      expect(errorSpy).toHaveBeenCalledWith(
+        expect.stringContaining(
+          'Monomer group template name cannot be empty or whitespace for template monomerGroupTemplate-',
+        ),
+      );
+      expect(editor.monomersLibraryParsedJson?.root.templates.length).toBe(
+        initialTemplatesCount,
+      );
+    });
   });
 });

packages/ketcher-core/src/application/editor/Editor.ts

@@ -460,6 +460,13 @@ export class CoreEditor {
         return;
       }
 
+      if (!templateDefinition.name?.trim()) {
+        KetcherLogger.error(
+          `Editor::updateMonomersLibrary: Monomer group template name cannot be empty or whitespace for template ${templateRef.$ref}. The template was not added to the library.`,
+        );
+        return;
+      }
+
       // eslint-disable-next-line  @typescript-eslint/no-non-null-assertion
       this._monomersLibraryParsedJson![templateRef.$ref] = templateDefinition;
       if (