Utils: Add an auto test for QtcProcess::exitCode()

Exit code handling can break during refactorings. This addition to
tst_QtcProcess tests negative, zero and positive exit codes of sub
prcesses that are launched asynchronously and synchronously.

Change-Id: Icbcc036d3fda7fa681958b57fd0a6f67d3a90352
Reviewed-by: hjk <hjk@qt.io>

tests/auto/qtcprocess/tst_qtcprocess.cpp

@@ -30,8 +30,19 @@
 
 #include <QtTest>
 
+#include <iostream>
+
 using namespace Utils;
 
+const char kExitCodeSubProcessCode[] = "QTC_TST_QTCPROCESS_EXITCODE_CODE";
+
+static void exitCodeSubProcessMain()
+{
+    const int exitCode = qEnvironmentVariableIntValue(kExitCodeSubProcessCode);
+    std::cout << "Exiting with code:" << exitCode << std::endl;
+    exit(exitCode);
+}
+
 class MacroMapExpander : public AbstractMacroExpander {
 public:
     virtual bool resolveMacro(const QString &name, QString *ret, QSet<AbstractMacroExpander*> &seen)
@@ -73,6 +84,8 @@ private slots:
     void iterations();
     void iteratorEditsWindows();
     void iteratorEditsLinux();
+    void exitCode_data();
+    void exitCode();
 
 private:
     void iteratorEditsHelper(OsType osType);
@@ -88,6 +101,9 @@ private:
 
 void tst_QtcProcess::initTestCase()
 {
+    if (qEnvironmentVariableIsSet(kExitCodeSubProcessCode))
+        exitCodeSubProcessMain();
+
     homeStr = QLatin1String("@HOME@");
     home = QDir::homePath();
 
@@ -743,6 +759,50 @@ void tst_QtcProcess::iteratorEditsLinux()
     iteratorEditsHelper(OsTypeLinux);
 }
 
+void tst_QtcProcess::exitCode_data()
+{
+    QTest::addColumn<int>("exitCode");
+
+    static const auto exitCodes = {
+#ifdef Q_OS_WIN
+        "99999999", "-255", "-1",
+#endif // Q_OS_WIN
+        "0", "1", "255"
+    };
+    for (auto exitCode : exitCodes)
+        QTest::newRow(exitCode) << QString::fromLatin1(exitCode).toInt();
+}
+
+void tst_QtcProcess::exitCode()
+{
+    QFETCH(int, exitCode);
+
+    Environment env = Environment::systemEnvironment();
+    env.set(kExitCodeSubProcessCode, QString::number(exitCode));
+    QStringList args = QCoreApplication::arguments();
+    const QString binary = args.takeFirst();
+    const CommandLine command(binary, args);
+
+    {
+        QtcProcess qtcP;
+        qtcP.setCommand(command);
+        qtcP.setEnvironment(env);
+        qtcP.start();
+        const bool finished = qtcP.waitForFinished();
+
+        QVERIFY(finished);
+        QCOMPARE(qtcP.exitCode(), exitCode);
+    }
+    {
+        SynchronousProcess sP;
+        sP.setCommand(command);
+        sP.setEnvironment(env);
+        sP.runBlocking();
+
+        QCOMPARE(sP.exitCode(), exitCode);
+    }
+}
+
 QTEST_MAIN(tst_QtcProcess)
 
 #include "tst_qtcprocess.moc"