`cleanup-repo-filelist-actions`: Cannot read property 'replaceWith' of null #3963

Refined GitHub version: 21.2.9 Chrome version: 88.0.4324.96 (macOS, x86_64) GitHub version: GitHub Enterprise Server 2.22.3

❌ Refined GitHub → cleanup-repo-filelist-actions → TypeError: Cannot read property 'replaceWith' of null
    at init (VM37 refined-github.js:7589)
    at runFeature (VM37 refined-github.js:2091)
    at setupPageLoad (VM37 refined-github.js:2099)
    at VM37 refined-github.js:2132 

I can reproduce this on any repo main page on GitHub Enterprise, but not on GitHub.com, so I unfortunately can't provide a URL.

However, looking at the cleanup-repo-filelist-actions code, I think the problem might be that the "Add file" span itself has the btn class (rather than a parent tag).

Here's a diff of document.querySelector('.btn[data-hotkey="t"]').nextElementSibling from GitHub.com → GHE:

$ diff -uw add-file_github-dot-com.html add-file_ghe.html

--- add-file_github-dot-com.html        2021-02-10 12:11:23.000000000 +0100
+++ add-file_ghe.html   2021-02-10 12:12:14.000000000 +0100
@@ -1,19 +1,18 @@
 <details class="details-overlay details-reset position-relative d-block">
-    <summary role="button" type="button" class="btn ml-2">
-        <span class="d-none d-md-flex flex-items-center">
+    <summary role="button">
+        <span class="ml-2 btn d-none d-md-flex flex-items-center">
             Add file
             <span class="dropdown-caret ml-1"></span>
         </span>
-        <span class="d-inline-block d-md-none">
+        <span class="ml-2 btn d-inline-block d-md-none">
             <svg aria-label="More options" class="octicon octicon-kebab-horizontal" height="16" viewBox="0 0 16 16" version="1.1" width="16" role="img">
                 <path d="M8 9a1.5 1.5 0 100-3 1.5 1.5 0 000 3zM1.5 9a1.5 1.5 0 100-3 1.5 1.5 0 000 3zm13 0a1.5 1.5 0 100-3 1.5 1.5 0 000 3z"></path>
             </svg>
         </span>
     </summary>
-    <div>
         <ul class="dropdown-menu dropdown-menu-sw">
             <li class="d-block d-md-none">
-                <a class="dropdown-item" data-hydro-click="…" data-hydro-click-hmac="…" data-ga-click="…" data-hotkey="t" data-pjax="true" href="/org-name/repo-name/find/master">
+            <a class="dropdown-item" data-ga-click="…" data-hotkey="t" data-pjax="true" href="/org-name/repo-name/find/master">
                     Go to file
                 </a>
             </li>
@@ -33,5 +32,4 @@
                 </a>
             </li>
         </ul>
-    </div>
 </details>