QML modules should define their preferred import alias

Background

QML modules can be imported in two ways: dump everything into a component's global namespace, or use a so-called import alias as a namespace. This is kind of all-or-nothing situation, unlike many other languages that allow selectively importing entities into the global namespace and even renaming then in the process.

Import aliases a.k.a. namespaces are cool for a whole bunch of reasons, including avoiding name collisions and improving clarity (which type comes from where) especially in the absence of Go To Definition if you are working without LSP support (e.g. because qmlls crashed five times in ten seconds, so my Sublime Text LSP manager just had to disable it, or if qmlls just fails to locate the types anyway because a QML module was not using the new shiny declarative type registration API).

In KDE we use import aliases a lot, for almost every module except QtQuick and QtQuick.Layouts, and we try to keep the import aliases consistent but it does not always happen. One of the biggest offenders is QtQuick.Controls module which you can find imported as QQC, QQC2, Controls and even QtControls2. FWIW I personally went for QQC2 because it is the most widespread variant, even though the "2" suffix became meaningless with the demise of QtQuick.Controls1 and deprecation of import versions in Qt 6.

Problem

Import aliases in large projects tend to drift out of konsistency, with all the usual "benefits" such as frustration and tension between teams or developers, and generally less copy-pasteable code.

Solution

We need a way for QML modules to define their preferred or suggested names, which tooling like qmlls could use when completing an import statement. In case if a module does not define one, qmlls could infer one from the last part of dotted import path, maybe magically applying per-word Capitalization if it can detect sub-words. There could be other mechanisms other than qmlls to use this metadata, and even qmlls might not be limited to auto-completion.

I'd imagine this to be an option in QML CMake API which would translate to some string key-value in qmldir and/or native module metadata.

Example

qt6_add_qml_module(KirigamiDelegates
    URI "org.kde.kirigami.delegates"
    IMPORT_AS KirigamiDelegates
    ...
)

qmldir:

module org.kde.kirigami.delegates
linktarget KirigamiDelegatesplugin
classname org_kde_kirigami_delegatesPlugin
importas KirigamiDelegates

QML:

import org.kde.kirigami.delegates /* qmlls suggests: «as KirigamiDelegates» */

SubtitleDelegate {
// ^ Alt+Enter code actions menu suggests an action to add
// «as KirigamiDelegates» import alias and prepend all the
// usages with this namespace. I'd imagine it would select
// all occurrences after that for multi-cursor editing, or
// ask for the alias name via modal dialog beforehand
// with a preferred name as an initial selected text.
}

Considerations

A project may want to override 3rd-party module's preferred import alias on a per-target or global level, for example because the project already has many consistent imports of that module which just happens to differ from the new upstream preferences. How would that look like?