Added tightLists option to copy_as_gfm markdown serializer

This removes extraneous newlines when copying comments
with an ordered list.

app/assets/javascripts/behaviors/markdown/copy_as_gfm.js

@@ -173,7 +173,9 @@ export class CopyAsGFM {
         wrapEl.appendChild(node.cloneNode(true));
         const doc = DOMParser.fromSchema(schema.default).parse(wrapEl);
-        const res = markdownSerializer.default.serialize(doc);
+        const res = markdownSerializer.default.serialize(doc, {
+          tightLists: true,
+        });
         return res;
       })
       .catch(() => {});

changelogs/unreleased/32714-copying-comment-with-ordered-list-includes-extraneous-newlines.yml

+---
+title: Fixed "Copying comment with ordered list includes extraneous newlines"
+merge_request: 25695
+author:
+type: fixed

spec/features/markdown/copy_as_gfm_spec.rb

@@ -55,15 +55,10 @@ describe 'Copy as GFM', :js do
           To see how GitLab looks please see the [features page on our website](https://about.gitlab.com/features/).
           * Manage Git repositories with fine grained access controls that keep your code secure
-
           * Perform code reviews and enhance collaboration with merge requests
-
           * Complete continuous integration (CI) and CD pipelines to builds, test, and deploy your applications
-
           * Each project can also have an issue tracker, issue board, and a wiki
-
           * Used by more than 100,000 organizations, GitLab is the most popular solution to manage Git repositories on-premises
-
           * Completely free and open source (MIT Expat license)
         GFM
       )
@@ -116,13 +111,11 @@ describe 'Copy as GFM', :js do
         <<~GFM,
           * [ ] Unchecked task
-
           * [x] Checked task
         GFM
         <<~GFM
           1. [ ] Unchecked ordered task
-
           1. [x] Checked ordered task
         GFM
       )
@@ -551,7 +544,6 @@ describe 'Copy as GFM', :js do
         <<~GFM,
           * List item
-
           * List item 2
         GFM
@@ -565,7 +557,6 @@ describe 'Copy as GFM', :js do
         # nested lists
         <<~GFM,
           * Nested
-
             * Lists
         GFM
@@ -578,7 +569,6 @@ describe 'Copy as GFM', :js do
         <<~GFM,
           1. Ordered list item
-
           1. Ordered list item 2
         GFM
@@ -592,7 +582,6 @@ describe 'Copy as GFM', :js do
         # nested ordered list
         <<~GFM,
           1. Nested
-
              1. Ordered lists
         GFM

spec/javascripts/behaviors/copy_as_gfm_spec.js

@@ -100,7 +100,7 @@ describe('CopyAsGFM', () => {
         simulateCopy();
         setTimeout(() => {
-          const expectedGFM = '* List Item1\n\n* List Item2';
+          const expectedGFM = '* List Item1\n* List Item2';
           expect(clipboardData.setData).toHaveBeenCalledWith('text/x-gfm', expectedGFM);
           done();
@@ -114,7 +114,7 @@ describe('CopyAsGFM', () => {
         simulateCopy();
         setTimeout(() => {
-          const expectedGFM = '1. List Item1\n\n1. List Item2';
+          const expectedGFM = '1. List Item1\n1. List Item2';
           expect(clipboardData.setData).toHaveBeenCalledWith('text/x-gfm', expectedGFM);
           done();