This adds the `ext.CodeMirror.v6.init` ResourceLoader module which
allows use of CodeMirror on `#wpTextbox1` without the use of WikiEditor
(the 'usebetatoolbar' preference). In order for users to opt-in to using
CodeMirror, we make the existing 'usecodemirror' option into a visible
preference. In addition, with two preferences related to CodeMirror, we
group them under a new heading 'Syntax highlighting'. More preferences
may be added later to this section following T359498.
When WikiEditor is not enabled, the layout of the action=edit page has
the textarea as a sibling to other visible content, like `.editOptions`.
Because of this, we can't simply append the CodeMirror DOM to the parent
like we were before, as that would put the visible editor beneath the
edit summary, Publish button, etc. Instead we rework the CodeMirror to
first add a wrapper around the textarea and use that as the parent. This
way, `.cm-editor` is always in the same place in the DOM as the native
textarea.
Line wrapping and focus/blur events are also moved to CodeMirror, as
these are needed when not using WikiEditor.
Bug: T190108
Change-Id: I4bc069e0d398aa7088e4f50bbd0ddda458b289c3
See https://w.wiki/9Twh for example usage with ResourceLoader.
Webpack is retired in favor of Rollup, which allows us to convert the
ECMAScript Modules into CommonJS modules for use by ResourceLoader.
We now have a file in dist/ for each RL module that we want to offer,
including the 'lib' module which includes the CM library itself.
Because Rollup has no knowledge of the ResourceLoader module registry,
the generated output requires other modules via relative path, when it
needs to be the RL module name. To get around this, we do a crude
find/replace after the files are generated. Hacky, but necessary to make
CodeMirror usable by gadgets and scripts that don't also want
WikiEditor.
Add new RL modules 'ext.CodeMirror.v6.lib' (vendor code) and
'ext.CodeMirror.v6' (the main CodeMirror class, sans WikiEditor).
Clean up extension.json, listing the v6 modules beneath the old ones.
Bug: T214989
Change-Id: Ide716247e545cf2bdd977bea645729564ebbe6e2
