uic test: Test Python

Add a test that checks for the Presence of Qt for Python
and runs Python compile tests on the baseline files.

Task-number: PYSIDE-797
Change-Id: I7e15c3c75261a7d94fc6654a95d49ba323cbe7d6
Reviewed-by: Cristian Maureira-Fredes <cristian.maureira-fredes@qt.io>

tests/auto/tools/uic/tst_uic.cpp

@@ -73,6 +73,9 @@ private Q_SLOTS:
     void compare();
     void compare_data() const;
 
+    void python();
+    void python_data() const;
+
     void runCompare();
 
 private:
@@ -83,6 +86,7 @@ private:
     QTemporaryDir m_generated;
     TestEntries m_testEntries;
     QRegularExpression m_versionRegexp;
+    QString m_python;
 };
 
 tst_uic::tst_uic()
@@ -98,6 +102,32 @@ static QByteArray msgProcessStartFailed(const QString &command, const QString &w
     return result.toLocal8Bit();
 }
 
+// Locate Python and check whether PySide2 is installed
+static QString locatePython(QTemporaryDir &generatedDir)
+{
+    QString python = QStandardPaths::findExecutable(QLatin1String("python"));
+    if (python.isEmpty()) {
+        qWarning("Cannot locate python, skipping tests");
+        return QString();
+    }
+    QFile importTestFile(generatedDir.filePath(QLatin1String("import_test.py")));
+    if (!importTestFile.open(QIODevice::WriteOnly| QIODevice::Text))
+        return QString();
+    importTestFile.write("import PySide2.QtCore\n");
+    importTestFile.close();
+    QProcess process;
+    process.start(python, {importTestFile.fileName()});
+    if (!process.waitForStarted() || !process.waitForFinished())
+        return QString();
+    if (process.exitStatus() != QProcess::NormalExit || process.exitCode() != 0) {
+        const QString stdErr = QString::fromLocal8Bit(process.readAllStandardError()).simplified();
+        qWarning("PySide2 is not installed (%s)", qPrintable(stdErr));
+        return QString();
+    }
+    importTestFile.remove();
+    return python;
+}
+
 void tst_uic::initTestCase()
 {
     QVERIFY2(m_generated.isValid(), qPrintable(m_generated.errorString()));
@@ -121,6 +151,8 @@ void tst_uic::initTestCase()
     populateTestEntries();
     QVERIFY(!m_testEntries.isEmpty());
     qDebug("%s", qPrintable(msg));
+
+    m_python = locatePython(m_generated);
 }
 
 void tst_uic::populateTestEntries()
@@ -343,5 +375,75 @@ void tst_uic::runCompare()
     QCOMPARE(generatedFileContents, originalFileContents);
 }
 
+// Let uic generate Python code and verify that it is syntactically
+// correct by compiling it into .pyc. This test is executed only
+// when python with an installed Qt for Python is detected (see locatePython()).
+
+static inline QByteArray msgCompilePythonFailed(const QByteArray &error)
+{
+    // If there is a line with blanks and caret indicating an error in the line
+    // above, insert the cursor into the offending line and remove the caret.
+    QByteArrayList lines = error.trimmed().split('\n');
+    for (int i = lines.size() -  1; i > 0; --i) {
+        const auto &line = lines.at(i);
+        const int caret = line.indexOf('^');
+        if (caret == 0 || (caret > 0 && line.at(caret - 1) == ' ')) {
+            lines.removeAt(i);
+            lines[i - 1].insert(caret, '|');
+            break;
+        }
+    }
+    return lines.join('\n');
+}
+
+void tst_uic::python_data() const
+{
+    QTest::addColumn<QString>("originalFile");
+    QTest::addColumn<QString>("generatedFile");
+
+    const int size = m_python.isEmpty()
+        ? qMin(1, m_testEntries.size()) : m_testEntries.size();
+    for (int i = 0; i < size; ++i) {
+        const TestEntry &te = m_testEntries.at(i);
+        // qprintsettingsoutput: variable named 'from' clashes with Python
+        if (!te.baselineBaseName.endsWith(QLatin1String("/qprintsettingsoutput"))) {
+            QString generatedFile = te.generatedFileName;
+            generatedFile.chop(1); // foo.h -> foo.py
+            generatedFile.append(QLatin1String("py"));
+            QTest::newRow(te.name.constData())
+                << (te.baselineBaseName + QLatin1String(".ui"))
+                << generatedFile;
+        }
+    }
+}
+
+void tst_uic::python()
+{
+    QFETCH(QString, originalFile);
+    QFETCH(QString, generatedFile);
+    if (m_python.isEmpty())
+        QSKIP("Python was not found");
+
+    QStringList uicArguments{QLatin1String("-g"), QLatin1String("python"),
+        originalFile, QLatin1String("-o"), generatedFile};
+    QProcess process;
+    process.setWorkingDirectory(m_generated.path());
+    process.start(m_command, uicArguments);
+    QVERIFY2(process.waitForStarted(), msgProcessStartFailed(m_command, process.errorString()));
+    QVERIFY(process.waitForFinished());
+    QCOMPARE(process.exitStatus(), QProcess::NormalExit);
+    QCOMPARE(process.exitCode(), 0);
+    QVERIFY(QFileInfo::exists(generatedFile));
+
+    // Test Python code generation by compiling the file
+    QStringList compileArguments{QLatin1String("-m"), QLatin1String("py_compile"), generatedFile};
+    process.start(m_python, compileArguments);
+    QVERIFY2(process.waitForStarted(), msgProcessStartFailed(m_command, process.errorString()));
+    QVERIFY(process.waitForFinished());
+    const bool compiled = process.exitStatus() == QProcess::NormalExit
+        && process.exitCode() == 0;
+    QVERIFY2(compiled, msgCompilePythonFailed(process.readAllStandardError()).constData());
+}
+
 QTEST_MAIN(tst_uic)
 #include "tst_uic.moc"