Enum key case

This warning category is spelled [enum-key-case] by qmllint.

Enum key starts with a lowercase letter

What happened?

An enum contains a key starting with a lowercase letter.

Why is that bad?

It can create ambiguity when performing lookups. Enum keys should start with an uppercase letter to distinguish them from properties of singletons and attached objects. Not following this convention can lead to unexpected results.

Example

// Properties.qml
import QtQuick

Item {
    enum Color { red, green, blue }
}

// Main.qml
import QtQuick

Item {
    // This lookup could be interpreted as a property lookup on a Singleton or attached object.
    property int i: Properties.green
}

To fix this warning, rename the key so it starts with an uppercase letter.

// Properties.qml
import QtQuick

Item {
    enum Color { Red, Green, Blue }
}

// Main.qml
import QtQuick

Item {
    // No ambiguity for the user or the QML engine, this is an enum lookup.
    property int i: Properties.Green
}