AutoTest: Avoid invalid parse results

If the document gets updated while typing we can get different
results when fetching the content and using positions inside the
content which might have updated milliseconds later.
Beside fetching only once ensure valid parse results by adding an
additional check for the used visitor.

Change-Id: Id1ba4a139a4dc497be0fbb5cf1f81004f3f8676c
Reviewed-by: David Schulz <david.schulz@theqtcompany.com>

src/plugins/autotest/testcodeparser.cpp

@@ -284,9 +284,10 @@ static QString quickTestSrcDir(const CppTools::CppModelManager *cppMM,
     return QString();
 }
 
-static QString testClass(const CppTools::CppModelManager *modelManager,
+static QString testClass(const CppTools::CppModelManager *modelManager, const QString &fileName)
-                         CPlusPlus::Document::Ptr &document)
 {
+    const QByteArray &fileContent = getFileContent(fileName);
+    CPlusPlus::Document::Ptr document = modelManager->document(fileName);
     const QList<CPlusPlus::Document::MacroUse> macros = document->macroUses();
 
     foreach (const CPlusPlus::Document::MacroUse &macro, macros) {
@@ -295,14 +296,13 @@ static QString testClass(const CppTools::CppModelManager *modelManager,
         const QByteArray name = macro.macro().name();
         if (TestUtils::isQTestMacro(name)) {
             const CPlusPlus::Document::Block arg = macro.arguments().at(0);
-            return QLatin1String(getFileContent(document->fileName())
+            return QLatin1String(fileContent.mid(arg.bytesBegin(),
-                                 .mid(arg.bytesBegin(), arg.bytesEnd() - arg.bytesBegin()));
+                                                 arg.bytesEnd() - arg.bytesBegin()));
         }
     }
     // check if one has used a self-defined macro or QTest::qExec() directly
     const CPlusPlus::Snapshot snapshot = modelManager->snapshot();
-    const QByteArray fileContent = getFileContent(document->fileName());
+    document = snapshot.preprocessedDocument(fileContent, fileName);
-    document = snapshot.preprocessedDocument(fileContent, document->fileName());
     document->check();
     CPlusPlus::AST *ast = document->translationUnit()->ast();
     TestAstVisitor astVisitor(document);
@@ -523,7 +523,7 @@ static void checkDocumentForTestCode(QFutureInterface<TestParseResult> futureInt
     } else if (testCaseNames.contains(fileName) // if we do a reparse
                || (includesQtTest(document, modelManager)
                    && qtTestLibDefined(modelManager, fileName))) {
-        QString testCaseName(testClass(modelManager, document));
+        QString testCaseName(testClass(modelManager, fileName));
         // we might be in a reparse without the original entry point with the QTest::qExec()
         if (testCaseName.isEmpty())
             testCaseName = testCaseNames.value(fileName);
@@ -537,6 +537,10 @@ static void checkDocumentForTestCode(QFutureInterface<TestParseResult> futureInt
 
             TestVisitor visitor(testCaseName);
             visitor.accept(declaringDoc->globalNamespace());
+
+            if (!visitor.resultValid())
+                return;
+
             const QMap<QString, TestCodeLocationAndType> testFunctions = visitor.privateSlots();
 
             QMap<QString, TestCodeLocationList> dataTags =

src/plugins/autotest/testvisitor.cpp

@@ -73,6 +73,8 @@ bool TestVisitor::visit(CPlusPlus::Class *symbol)
         if (className != m_className)
             continue;
 
+        m_valid = true;
+
         if (const auto func = type->asFunctionType()) {
             if (func->isSlot() && member->isPrivate()) {
                 const QString name = o.prettyName(func->name());

src/plugins/autotest/testvisitor.h

@@ -52,6 +52,7 @@ public:
     virtual ~TestVisitor();
 
     QMap<QString, TestCodeLocationAndType> privateSlots() const { return m_privSlots; }
+    bool resultValid() const { return m_valid; }
 
     bool visit(CPlusPlus::Class *symbol);
 
@@ -59,6 +60,7 @@ private:
     CppTools::SymbolFinder m_symbolFinder;
     QString m_className;
     QMap<QString, TestCodeLocationAndType> m_privSlots;
+    bool m_valid = false;
 };
 
 class TestAstVisitor : public CPlusPlus::ASTVisitor