Console API: Add console.assert

console.assert tests if an expression is true. If it is false,
it writes a message to the console and prints the JavaScript
stack trace at that point.

Change-Id: I5487552cb8a947e1947914166834e0bdedba3354
Reviewed-by: Kai Koehne <kai.koehne@nokia.com>

doc/src/declarative/qdeclarativedebugging.qdoc

@@ -49,6 +49,19 @@ The output is generated using the qDebug, qWarning, qCritical methods in C++
 \hint Setting the environment variable QML_CONSOLE_EXTENDED also prints the source
 code location of the call.
 
+\section2 Assert
+
+\c console.assert tests that an expression is true. If not, it will write an optional message
+to the console and print the stack trace.
+
+\qml
+function f() {
+  var x = 12
+  console.assert(x == 12, "This will pass");
+  console.assert(x > 12, "This will fail");
+}
+\endqml
+
 \section2 Timer
 
 \c console.time and console.timeEnd log the time (in milliseconds) that was spent between

src/declarative/qml/v8/qdeclarativebuiltinfunctions.cpp

@@ -94,6 +94,22 @@ static QString extendMessage(const QString &msg) {
     return msg;
 }
 
+static void printStack() {
+    //The v8 default is currently 10 stack frames.
+    v8::Handle<v8::StackTrace> stackTrace =
+        v8::StackTrace::CurrentStackTrace(10, v8::StackTrace::kOverview);
+    int stackCount = stackTrace->GetFrameCount();
+
+    for (int i = 0; i < stackCount; i++) {
+        v8::Local<v8::StackFrame> frame = stackTrace->GetFrame(i);
+        v8::String::Utf8Value func_name(frame->GetFunctionName());
+        v8::String::Utf8Value script_name(frame->GetScriptName());
+        int lineNumber = frame->GetLineNumber();
+        int columnNumber = frame->GetColumn();
+        qDebug("%s (%s:%d:%d)\n", *func_name, *script_name, lineNumber, columnNumber);
+    }
+}
+
 v8::Handle<v8::Value> console(ConsoleLogTypes logType, const v8::Arguments &args)
 {
     v8::HandleScope handleScope;
@@ -252,19 +268,7 @@ v8::Handle<v8::Value> consoleTrace(const v8::Arguments &args)
     if (args.Length() != 0)
         V8THROW_ERROR("console.trace(): Invalid arguments");
 
-    //The v8 default is currently 10 stack frames.
-    v8::Handle<v8::StackTrace> stackTrace =
-        v8::StackTrace::CurrentStackTrace(10, v8::StackTrace::kOverview);
-    int stackCount = stackTrace->GetFrameCount();
-
-    for (int i = 0; i < stackCount; i++) {
-        v8::Local<v8::StackFrame> frame = stackTrace->GetFrame(i);
-        v8::String::Utf8Value func_name(frame->GetFunctionName());
-        v8::String::Utf8Value script_name(frame->GetScriptName());
-        int lineNumber = frame->GetLineNumber();
-        int columnNumber = frame->GetColumn();
-        qDebug("%s (%s:%d:%d)\n", *func_name, *script_name, lineNumber, columnNumber);
-    }
+    printStack();
     return v8::Undefined();
 }
 
@@ -273,6 +277,28 @@ v8::Handle<v8::Value> consoleWarn(const v8::Arguments &args)
     return console(Warn, args);
 }
 
+v8::Handle<v8::Value> consoleAssert(const v8::Arguments &args)
+{
+    if (args.Length() == 0)
+        V8THROW_ERROR("console.assert(): Missing argument");
+
+    if (!args[0]->ToBoolean()->Value()) {
+        QString message;
+        for (int i = 1; i < args.Length(); ++i) {
+            if (i != 1)
+                message.append(QLatin1Char(' '));
+
+            v8::Local<v8::Value> value = args[i];
+            message.append(V8ENGINE()->toString(value->ToString()));
+        }
+
+        message = extendMessage(message);
+        qCritical("%s", qPrintable(message));
+        printStack();
+    }
+    return v8::Undefined();
+}
+
 v8::Handle<v8::Value> stringArg(const v8::Arguments &args)
 {
     QString value = V8ENGINE()->toString(args.This()->ToString());

src/declarative/qml/v8/qdeclarativebuiltinfunctions_p.h

@@ -70,6 +70,7 @@ v8::Handle<v8::Value> consoleTimeEnd(const v8::Arguments &args);
 v8::Handle<v8::Value> consoleCount(const v8::Arguments &args);
 v8::Handle<v8::Value> consoleTrace(const v8::Arguments &args);
 v8::Handle<v8::Value> consoleWarn(const v8::Arguments &args);
+v8::Handle<v8::Value> consoleAssert(const v8::Arguments &args);
 v8::Handle<v8::Value> isQtObject(const v8::Arguments &args);
 v8::Handle<v8::Value> rgba(const v8::Arguments &args);
 v8::Handle<v8::Value> hsla(const v8::Arguments &args);

src/declarative/qml/v8/qv8engine.cpp

@@ -530,6 +530,7 @@ void QV8Engine::initializeGlobal(v8::Handle<v8::Object> global)
     console->Set(v8::String::New("info"), consoleLogFn);
     console->Set(v8::String::New("warn"), V8FUNCTION(consoleWarn, this));
     console->Set(v8::String::New("error"), V8FUNCTION(consoleError, this));
+    console->Set(v8::String::New("assert"), V8FUNCTION(consoleAssert, this));
 
     console->Set(v8::String::New("count"), V8FUNCTION(consoleCount, this));
     console->Set(v8::String::New("profile"), V8FUNCTION(consoleProfile, this));

tests/auto/declarative/qdeclarativeconsole/data/assert.qml

@@ -0,0 +1,62 @@
+/****************************************************************************
+**
+** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (qt-info@nokia.com)
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** GNU Lesser General Public License Usage
+** This file may be used under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation and
+** appearing in the file LICENSE.LGPL included in the packaging of this
+** file. Please review the following information to ensure the GNU Lesser
+** General Public License version 2.1 requirements will be met:
+** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain additional
+** rights. These rights are described in the Nokia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU General
+** Public License version 3.0 as published by the Free Software Foundation
+** and appearing in the file LICENSE.GPL included in the packaging of this
+** file. Please review the following information to ensure the GNU General
+** Public License version 3.0 requirements will be met:
+** http://www.gnu.org/copyleft/gpl.html.
+**
+** Other Usage
+** Alternatively, this file may be used in accordance with the terms and
+** conditions contained in a signed written agreement between you and Nokia.
+**
+**
+**
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+import QtQuick 2.0
+
+QtObject {
+    property int q:1
+    function assertFail() {
+        console.assert(0, "This will fail too")
+    }
+
+    Component.onCompleted: {
+        var x = 12;
+        console.assert(x == 12, "This will pass");
+        try {
+        console.assert(x < 12, "This will fail");
+        } catch (e) {
+            console.log(e);
+        }
+        console.assert("x < 12", "This will pass too")
+        assertFail();
+        console.assert(1)
+    }
+}

tests/auto/declarative/qdeclarativeconsole/tst_qdeclarativeconsole.cpp

@@ -54,6 +54,7 @@ private slots:
     void logging();
     void tracing();
     void profiling();
+    void assert();
 
 private:
     QDeclarativeEngine engine;
@@ -120,6 +121,25 @@ void tst_qdeclarativeconsole::profiling()
     delete object;
 }
 
+void tst_qdeclarativeconsole::assert()
+{
+    QUrl testUrl = testFileUrl("assert.qml");
+
+    // assert()
+    QTest::ignoreMessage(QtCriticalMsg, "This will fail");
+    QTest::ignoreMessage(QtCriticalMsg, "This will fail too");
+    QString trace1 = QString::fromLatin1("onCompleted (%1:%2:%3)\n").arg(testUrl.toString()).arg(54).arg(17);
+    QString trace2 = QString::fromLatin1("onCompleted (%1:%2:%3)\n").arg(testUrl.toString()).arg(59).arg(9);
+    QString trace3 = QString::fromLatin1("assertFail (%1:%2:%3)\n").arg(testUrl.toString()).arg(47).arg(17);
+    QTest::ignoreMessage(QtDebugMsg, qPrintable(trace1));
+    QTest::ignoreMessage(QtDebugMsg, qPrintable(trace2));
+    QTest::ignoreMessage(QtDebugMsg, qPrintable(trace3));
+
+    QDeclarativeComponent component(&engine, testUrl);
+    QObject *object = component.create();
+    QVERIFY(object != 0);
+    delete object;
+}
 
 QTEST_MAIN(tst_qdeclarativeconsole)