CodeMirror breaks JavaScript on load in ext.CodeMirror.js: line 187:3 with:
```
load.php?debug=false&lang=en&modules=jquery%2Cmediawiki|mediawiki.legacy.wikibits&only=scripts&skin=vector&version=1faydix:52 Uncaught TypeError: $button.toggleClass(...).data(...) is not a function
at updateToolbarButton (load.php?debug=false&lang=en&modules=ext.CodeMirror|ext.CodeMirror.data%2Clib|ext.CodeMirror.mode.mediawiki|ext.centralauth.centralautologin.clearcookie|ext.echo.api%2Cinit|ext.math.editbutton.enabler|ext.wikimediaEvents.loggedin|jquery.tipsy|mediawiki.action.edit.preview|mediawiki.api.messages|mediawiki.diff.styles|mediawiki.page.watch.ajax|oojs-ui-core%2Csite&skin=vector&version=089p435:4)
at HTMLDocument.<anonymous> (load.php?debug=false&lang=en&modules=ext.CodeMirror|ext.CodeMirror.data%2Clib|ext.CodeMirror.mode.mediawiki|ext.centralauth.centralautologin.clearcookie|ext.echo.api%2Cinit|ext.math.editbutton.enabler|ext.wikimediaEvents.loggedin|jquery.tipsy|mediawiki.action.edit.preview|mediawiki.api.messages|mediawiki.diff.styles|mediawiki.page.watch.ajax|oojs-ui-core%2Csite&skin=vector&version=089p435:6)
at mightThrow (load.php?debug=false&lang=en&modules=jquery%2Cmediawiki|mediawiki.legacy.wikibits&only=scripts&skin=vector&version=1faydix:49)
at process (load.php?debug=false&lang=en&modules=jquery%2Cmediawiki|mediawiki.legacy.wikibits&only=scripts&skin=vector&version=1faydix:50)
```
(tested in Firefox and Chrome on Commons)