CodeMirror 6 plugin API: Multiple plugins can't register autocompletion sources without enabling CodeMirror's built-in autocomplete

[personalizedrefrigerator]

Operating system

Linux

Joplin version

≥2.14.6

Current behaviour

See https://discuss.codemirror.net/t/autocompletion-merging-override-in-config/7853/2.

At present, CodeMirror 6 content scripts can register custom completions as follows:

const customCompletion = completeFromList([ 'completion1', 'completion2' ]);
editorControl.addExtension([
    autocompletion(),
    EditorState.languageData.of(() => [{ autocomplete: customCompletion }]),
]);

The above, however, enables CodeMirror's built-in autocompletions (e.g. autocompleting function in JavaScript code blocks or HTML tags in markdown), which may not be desired.

An alternative is something similar to this:

const customCompletion = completeFromList([ 'completion1', 'completion2' ]);
editorControl.addExtension([
    autocompletion({ overrides: [customCompletion] }),
]);

However, this fails if more than one plugin tries to register completions this way.

Expected behavior

Multiple plugins should be able to add autocompletion sources without enabling CodeMirror's built-in autocomplete.