3 files changed, 48 insertions, 14 deletions
diff --git a/src/qmlcompiler/qqmljsimportvisitor.cpp b/src/qmlcompiler/qqmljsimportvisitor.cpp
index 6f1558383d..6c1d22c90d 100644
--- a/src/qmlcompiler/qqmljsimportvisitor.cpp
+++ b/src/qmlcompiler/qqmljsimportvisitor.cpp
@@ -2398,6 +2398,19 @@ void QQmlJSImportVisitor::endVisit(UiArrayBinding *arrayBinding)
     }
 }
 
+void QQmlJSImportVisitor::handleDuplicateEnums(UiEnumMemberList *members, const QString &key,
+                                               const QQmlJS::SourceLocation &location)
+{
+    m_logger->log(u"Enum key '%1' has already been declared"_s.arg(key), qmlSyntax, location);
+    for (const auto *member = members; member; member = member->next) {
+        if (member->member.toString() == key) {
+            m_logger->log(u"Note: previous declaration of '%1' here"_s.arg(key), qmlSyntax,
+                          member->memberToken);
+            return;
+        }
+    }
+}
+
 bool QQmlJSImportVisitor::visit(QQmlJS::AST::UiEnumDeclaration *uied)
 {
     if (m_currentScope->inlineComponentName()) {
@@ -2407,7 +2420,16 @@ bool QQmlJSImportVisitor::visit(QQmlJS::AST::UiEnumDeclaration *uied)
     QQmlJSMetaEnum qmlEnum(uied->name.toString());
     qmlEnum.setIsQml(true);
     for (const auto *member = uied->members; member; member = member->next) {
-        qmlEnum.addKey(member->member.toString());
+        const QString key = member->member.toString();
+
+        if (!key.front().isUpper()) {
+            m_logger->log(u"Enum keys should start with an uppercase."_s, qmlSyntax,
+                          member->memberToken);
+        }
+        if (qmlEnum.hasKey(key))
+            handleDuplicateEnums(uied->members, key, member->memberToken);
+
+        qmlEnum.addKey(key);
         qmlEnum.addValue(int(member->value));
     }
     m_currentScope->addOwnEnumeration(qmlEnum);
diff --git a/src/qmlcompiler/qqmljsimportvisitor_p.h b/src/qmlcompiler/qqmljsimportvisitor_p.h
index 0d12ea0b6a..5de1c80c32 100644
--- a/src/qmlcompiler/qqmljsimportvisitor_p.h
+++ b/src/qmlcompiler/qqmljsimportvisitor_p.h
@@ -109,6 +109,8 @@ protected:
     bool visit(QQmlJS::AST::UiArrayBinding *) override;
     void endVisit(QQmlJS::AST::UiArrayBinding *) override;
     bool visit(QQmlJS::AST::UiEnumDeclaration *uied) override;
+    void handleDuplicateEnums(QQmlJS::AST::UiEnumMemberList *members, const QString &key,
+                              const QQmlJS::SourceLocation &location);
     bool visit(QQmlJS::AST::FunctionExpression *fexpr) override;
     void endVisit(QQmlJS::AST::FunctionExpression *) override;
     bool visit(QQmlJS::AST::UiSourceElement *) override;
diff --git a/tests/auto/qml/qmllint/tst_qmllint.cpp b/tests/auto/qml/qmllint/tst_qmllint.cpp
index a151b70f13..5aaf05612b 100644
--- a/tests/auto/qml/qmllint/tst_qmllint.cpp
+++ b/tests/auto/qml/qmllint/tst_qmllint.cpp
@@ -1324,6 +1324,20 @@ void TestQmllint::dirtyQmlCode()
             });
 }
 
+static void addLocationOffsetTo(TestQmllint::Result *result, qsizetype lineOffset,
+                                qsizetype columnOffset = 0)
+{
+    for (auto *messages :
+         { &result->expectedMessages, &result->badMessages, &result->expectedReplacements }) {
+        for (auto &message : *messages) {
+            if (message.line != 0)
+                message.line += lineOffset;
+            if (message.column != 0)
+                message.column += columnOffset;
+        }
+    }
+}
+
 void TestQmllint::dirtyQmlSnippet_data()
 {
     QTest::addColumn<QString>("code");
@@ -1331,6 +1345,11 @@ void TestQmllint::dirtyQmlSnippet_data()
 
     QTest::newRow("testSnippet") << u"property int qwer: \"Hello\""_s
                                  << Result{ { { "Cannot assign literal of type string to int"_L1 } } };
+
+    QTest::newRow("enum") << u"enum Hello { World, Kitty, World, dlrow }"_s
+                          << Result{ { { "Enum key 'World' has already been declared"_L1, 1, 28 },
+                                       { "Note: previous declaration of 'World' here"_L1, 1, 14 },
+                                       { "Enum keys should start with an uppercase"_L1, 1, 35 } } };
 }
 
 void TestQmllint::dirtyQmlSnippet()
@@ -1338,7 +1357,9 @@ void TestQmllint::dirtyQmlSnippet()
     QFETCH(QString, code);
     QFETCH(Result, result);
 
-    QString qmlCode = "import QtQuick\nItem {%1}"_L1.arg(code);
+    QString qmlCode = "import QtQuick\nItem {\n%1}"_L1.arg(code);
+
+    addLocationOffsetTo(&result, 2);
 
     QJsonArray warnings;
     callQmllint(QString(), result.flags.testFlag(Result::ExitsNormally), &warnings, {}, {}, {},
@@ -1353,6 +1374,7 @@ void TestQmllint::cleanQmlSnippet_data()
     QTest::addColumn<QString>("code");
 
     QTest::newRow("testSnippet") << u"property int qwer: 123"_s;
+    QTest::newRow("enum") << u"enum Hello { World, Kitty, DlroW }"_s;
 }
 
 void TestQmllint::cleanQmlSnippet()
@@ -1386,18 +1408,6 @@ void TestQmllint::dirtyJsSnippet_data()
                                     };
 }
 
-static void addLocationOffsetTo(TestQmllint::Result *result, qsizetype lineOffset,
-                                qsizetype columnOffset = 0)
-{
-    for (auto *messages :
-         { &result->expectedMessages, &result->badMessages, &result->expectedReplacements }) {
-        for (auto &message : *messages) {
-            message.line += lineOffset;
-            message.column += columnOffset;
-        }
-    }
-}
-
 void TestQmllint::dirtyJsSnippet()
 {
     QFETCH(QString, code);