Wizards: Bump QtQuick import version in file wizards

Use 2.15 as default, plus a little heuristic to use the same version as
other files in the project.

Fixes: QTCREATORBUG-27614
Change-Id: Ic84db5da97a9f35a2ad0e57fd47b75fb32a0b7f8
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: <github-actions-qt-creator@cristianadam.eu>
Reviewed-by: Alessandro Portale <alessandro.portale@qt.io>

share/qtcreator/templates/wizards/autotest/files/tst_qml.tmpl

@@ -1,4 +1,4 @@
-import QtQuick 2.0
+import QtQuick 2.15
 import QtTest 1.0
 
 TestCase {

share/qtcreator/templates/wizards/files/qtquick2/file.qml.tpl

@@ -1,4 +1,4 @@
-import QtQuick 2.0
+import QtQuick %{QtQuickVersion}
 
 Item {
 

share/qtcreator/templates/wizards/files/qtquick2/wizard.json

@@ -3,13 +3,16 @@
     "supportedProjectTypes": [ ],
     "id": "Q.Qml.2",
     "category": "R.Qt",
-    "trDescription": "Creates a QML file with boilerplate code, starting with \"import QtQuick 2.0\".",
+    "trDescription": "Creates a QML file with boilerplate code, starting with \"import QtQuick\".",
     "trDisplayName": "QML File (Qt Quick 2)",
     "trDisplayCategory": "Qt",
     "iconText": "qml",
     "enabled": "%{JS: value('Plugins').indexOf('QmlJSEditor') >= 0}",
 
-    "options": { "key": "DefaultSuffix", "value": "%{JS: Util.preferredSuffix('text/x-qml')}" },
+    "options": [
+        {"key": "DefaultSuffix", "value": "%{JS: Util.preferredSuffix('text/x-qml')}"},
+        {"key": "QtQuickVersion", "value": "%{JS: Util.qtQuickVersion(value('TargetPath'))}"}
+    ],
 
     "pages" :
     [

src/plugins/coreplugin/corejsextensions.cpp

@@ -32,8 +32,10 @@
 #include <utils/qtcassert.h>
 
 #include <QDir>
+#include <QDirIterator>
 #include <QTemporaryFile>
 #include <QVariant>
+#include <QVersionNumber>
 
 namespace Core {
 namespace Internal {
@@ -165,5 +167,34 @@ QString UtilsJsExtension::asciify(const QString &input) const
     return result;
 }
 
+QString UtilsJsExtension::qtQuickVersion(const QString &filePath) const
+{
+    QDirIterator dirIt(Utils::FilePath::fromString(filePath).parentDir().path(), {"*.qml"},
+                       QDir::Files, QDirIterator::Subdirectories);
+    while (dirIt.hasNext()) {
+        Utils::FileReader reader;
+        if (!reader.fetch(Utils::FilePath::fromString(dirIt.next())))
+            continue;
+        const QString data = QString::fromUtf8(reader.data());
+        static const QString importString("import QtQuick");
+        const int importIndex = data.indexOf(importString);
+        if (importIndex == -1)
+            continue;
+        const int versionIndex = importIndex + importString.length();
+        const int newLineIndex = data.indexOf('\n', versionIndex);
+        if (newLineIndex == -1)
+            continue;
+        const QString versionString = data.mid(versionIndex,
+                                               newLineIndex - versionIndex).simplified();
+        if (versionString.isEmpty())
+            return {};
+        const auto version = QVersionNumber::fromString(versionString);
+        if (version.isNull())
+            return {};
+        return version.toString();
+    }
+    return QLatin1String("2.15");
+}
+
 } // namespace Internal
 } // namespace Core

src/plugins/coreplugin/corejsextensions.h

@@ -76,6 +76,9 @@ public:
 
     // Generate a ascii-only string:
     Q_INVOKABLE QString asciify(const QString &input) const;
+
+    // Heuristic to find out which QtQuick import version to use for the given file.
+    Q_INVOKABLE QString qtQuickVersion(const QString &filePath) const;
 };
 
 } // namespace Internal