Introduce JSON validation

Support basic validation for JSON files according to the
draft http://tools.ietf.org/html/draft-zyp-json-schema-03

.

This is not a complete implementation yet, but it should
already be useful, since "type" verification along with
many of the attributes is done.

Change-Id: I364bc98dd92937c5e2ea9cba7e15ed8e03eb9beb
Reviewed-by: Erik Verbruggen <erik.verbruggen@nokia.com>

src/libs/qmljs/jsoncheck.cpp

+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2012 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+**
+** 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.
+**
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at info@qt.nokia.com.
+**
+**************************************************************************/
+
+#include "jsoncheck.h"
+
+#include <parser/qmljsast_p.h>
+#include <utils/qtcassert.h>
+
+#include <QtCore/QDebug>
+#include <QtCore/QLatin1String>
+#include <QtCore/QRegExp>
+#include <QtCore/QMap>
+
+#include <cmath>
+
+using namespace QmlJS;
+using namespace QmlJS::AST;
+using namespace QmlJS::StaticAnalysis;
+using namespace Utils;
+
+JsonCheck::JsonCheck(Document::Ptr doc)
+    : m_doc(doc)
+    , m_schema(0)
+{
+    QTC_CHECK(m_doc->ast());
+}
+
+JsonCheck::~JsonCheck()
+{}
+
+QList<Message> JsonCheck::operator ()(JsonSchema *schema)
+{
+    QTC_ASSERT(schema, return QList<Message>());
+
+    m_schema = schema;
+
+    m_analysis.push(AnalysisData());
+    processSchema(m_doc->ast());
+    const AnalysisData &analysis = m_analysis.pop();
+
+    return analysis.m_messages;
+}
+
+bool JsonCheck::preVisit(Node *ast)
+{
+    if (!m_firstLoc.isValid()) {
+        if (ExpressionNode *expr = ast->expressionCast())
+            m_firstLoc = expr->firstSourceLocation();
+    }
+
+    m_analysis.push(AnalysisData());
+
+    return true;
+}
+
+void JsonCheck::postVisit(Node *)
+{
+    const AnalysisData &previous = m_analysis.pop();
+    if (previous.m_messages.isEmpty())
+        analysis()->m_hasMatch = true;
+    else
+        analysis()->m_messages.append(previous.m_messages);
+    analysis()->m_ranking += previous.m_ranking;
+}
+
+bool JsonCheck::visit(ObjectLiteral *ast)
+{
+    if (!proceedCheck(JsonValue::Object, ast->lbraceToken))
+        return false;
+
+    analysis()->boostRanking();
+
+    const QStringList &properties = m_schema->properties();
+    if (properties.isEmpty())
+        return false;
+
+    QSet<QString> propertiesFound;
+    for (PropertyNameAndValueList *it = ast->properties; it; it = it->next) {
+        StringLiteralPropertyName *literalName = cast<StringLiteralPropertyName *>(it->name);
+        if (literalName) {
+            const QString &propertyName = literalName->id.toString();
+            if (m_schema->hasPropertySchema(propertyName)) {
+                analysis()->boostRanking();
+                propertiesFound.insert(propertyName);
+                // Sec. 5.2: "... each property definition's value MUST be a schema..."
+                m_schema->enterNestedPropertySchema(propertyName);
+                processSchema(it->value);
+                m_schema->leaveNestedSchema();
+            } else {
+                analysis()->m_messages.append(Message(ErrInvalidPropertyName,
+                                                      literalName->firstSourceLocation(),
+                                                      propertyName, QString(),
+                                                      false));
+            }
+        }  else {
+            analysis()->m_messages.append(Message(ErrStringValueExpected,
+                                                  it->name->firstSourceLocation(),
+                                                  QString(), QString(),
+                                                  false));
+        }
+    }
+
+    QStringList missing;
+    foreach (const QString &property, properties) {
+        if (!propertiesFound.contains(property)) {
+            m_schema->enterNestedPropertySchema(property);
+            if (m_schema->required())
+                missing.append(property);
+            m_schema->leaveNestedSchema();
+        }
+    }
+    if (!missing.isEmpty()) {
+        analysis()->m_messages.append(Message(ErrMissingRequiredProperty,
+                                              ast->firstSourceLocation(),
+                                              missing.join(QLatin1String(", ")),
+                                              QString(),
+                                              false));
+    } else {
+        analysis()->boostRanking();
+    }
+
+    return false;
+}
+
+bool JsonCheck::visit(ArrayLiteral *ast)
+{
+    if (!proceedCheck(JsonValue::Array, ast->firstSourceLocation()))
+        return false;
+
+    analysis()->boostRanking();
+
+    if (m_schema->hasItemSchema()) {
+        // Sec. 5.5: "When this attribute value is a schema... all the items in the array MUST
+        // be valid according to the schema."
+        m_schema->enterNestedItemSchema();
+        for (ElementList *element = ast->elements; element; element = element->next)
+            processSchema(element->expression);
+        m_schema->leaveNestedSchema();
+    } else if (m_schema->hasItemArraySchema()) {
+        // Sec. 5.5: "When this attribute value is an array of schemas... each position in the
+        // instance array MUST conform to the schema in the corresponding position for this array."
+        int current = 0;
+        const int arraySize = m_schema->itemArraySchemaSize();
+        for (ElementList *element = ast->elements; element; element = element->next, ++current) {
+            if (current < arraySize) {
+                if (m_schema->maybeEnterNestedArraySchema(current)) {
+                    processSchema(element->expression);
+                    m_schema->leaveNestedSchema();
+                } else {
+                    Node::accept(element->expression, this);
+                }
+            } else {
+                // TODO: Handle additionalItems.
+            }
+        }
+        if (current < arraySize
+                || (current > arraySize && !m_schema->hasAdditionalItems())) {
+            analysis()->m_messages.append(Message(ErrInvalidArrayValueLength,
+                                                  ast->firstSourceLocation(),
+                                                  QString::number(arraySize), QString(), false));
+        }
+    }
+
+    return false;
+}
+
+bool JsonCheck::visit(NullExpression *ast)
+{
+    if (proceedCheck(JsonValue::Null, ast->firstSourceLocation()))
+        return false;
+
+    analysis()->boostRanking();
+
+    return false;
+}
+
+bool JsonCheck::visit(TrueLiteral *ast)
+{
+    if (!proceedCheck(JsonValue::Boolean, ast->firstSourceLocation()))
+        return false;
+
+    analysis()->boostRanking();
+
+    return false;
+}
+
+bool JsonCheck::visit(FalseLiteral *ast)
+{
+    if (!proceedCheck(JsonValue::Boolean, ast->firstSourceLocation()))
+        return false;
+
+    analysis()->boostRanking();
+
+    return false;
+}
+
+bool JsonCheck::visit(NumericLiteral *ast)
+{
+    double dummy;
+    if (std::abs(std::modf(ast->value, &dummy)) > 0.000000001) {
+        if (!proceedCheck(JsonValue::Double, ast->firstSourceLocation()))
+            return false;
+    } else if (!proceedCheck(JsonValue::Int, ast->firstSourceLocation())) {
+        return false;
+    }
+
+    analysis()->boostRanking();
+
+    if (m_schema->hasMinimum()) {
+        double minValue = m_schema->minimum();
+        if (ast->value < minValue) {
+            analysis()->m_messages.append(Message(ErrLargerNumberValueExpected,
+                                                  ast->firstSourceLocation(),
+                                                  QString::number(minValue), QString(), false));
+        } else if (m_schema->hasExclusiveMinimum()
+                   && std::abs(ast->value - minValue) > 0.000000001) {
+            analysis()->m_messages.append(Message(ErrMinimumNumberValueIsExclusive,
+                                                  ast->firstSourceLocation(),
+                                                  QString(), QString(), false));
+        } else {
+            analysis()->boostRanking();
+        }
+    }
+
+    if (m_schema->hasMaximum()) {
+        double maxValue = m_schema->maximum();
+        if (ast->value > maxValue) {
+            analysis()->m_messages.append(Message(ErrSmallerNumberValueExpected,
+                                                  ast->firstSourceLocation(),
+                                                  QString::number(maxValue), QString(), false));
+        } else if (m_schema->hasExclusiveMaximum()) {
+            analysis()->m_messages.append(Message(ErrMaximumNumberValueIsExclusive,
+                                                  ast->firstSourceLocation(),
+                                                  QString(), QString(), false));
+        } else {
+            analysis()->boostRanking();
+        }
+    }
+
+    return false;
+}
+
+bool JsonCheck::visit(StringLiteral *ast)
+{
+    if (!proceedCheck(JsonValue::String, ast->firstSourceLocation()))
+        return false;
+
+    analysis()->boostRanking();
+
+    const QString &literal = ast->value.toString();
+
+    const QString &pattern = m_schema->pattern();
+    if (!pattern.isEmpty()) {
+        QRegExp regExp(pattern);
+        if (regExp.indexIn(literal) == -1) {
+            analysis()->m_messages.append(Message(ErrInvalidStringValuePattern,
+                                                  ast->firstSourceLocation(),
+                                                  QString(), QString(), false));
+            return false;
+        }
+        analysis()->boostRanking(3); // Treat string patterns with higher weight.
+    }
+
+    int expectedLength = m_schema->minimumLength();
+    if (expectedLength != -1) {
+        if (literal.length() < expectedLength) {
+            analysis()->m_messages.append(Message(ErrLongerStringValueExpected,
+                                                  ast->firstSourceLocation(),
+                                                  QString::number(expectedLength), QString(),
+                                                  false));
+        } else {
+            analysis()->boostRanking();
+        }
+    }
+
+    expectedLength = m_schema->maximumLength();
+    if (expectedLength != -1) {
+        if (literal.length() > expectedLength) {
+            analysis()->m_messages.append(Message(ErrShorterStringValueExpected,
+                                                  ast->firstSourceLocation(),
+                                                  QString::number(expectedLength), QString(),
+                                                  false));
+        } else {
+            analysis()->boostRanking();
+        }
+    }
+
+    return false;
+}
+
+static QString formatExpectedTypes(QStringList all)
+{
+    all.removeDuplicates();
+    return all.join(QLatin1String(", or "));
+}
+
+void JsonCheck::processSchema(Node *ast)
+{
+    if (m_schema->hasTypeSchema()) {
+        m_schema->enterNestedTypeSchema();
+        processSchema(ast);
+        m_schema->leaveNestedSchema();
+    } else if (m_schema->hasUnionSchema()) {
+        // Sec. 5.1: "... value is valid if it is of the same type as one of the simple
+        // type definitions, or valid by one of the schemas, in the array."
+        int bestRank = 0;
+        QList<StaticAnalysis::Message> bestErrorGuess;
+        int current = 0;
+        const int unionSize = m_schema->unionSchemaSize();
+        m_analysis.push(AnalysisData());
+        for (; current < unionSize; ++current) {
+            if (m_schema->maybeEnterNestedUnionSchema(current)) {
+                processSchema(ast);
+                m_schema->leaveNestedSchema();
+            } else {
+                Node::accept(ast, this);
+            }
+            if (analysis()->m_hasMatch)
+                break;
+
+            if (analysis()->m_ranking >= bestRank) {
+                bestRank = analysis()->m_ranking;
+                bestErrorGuess = analysis()->m_messages;
+            }
+            analysis()->m_ranking = 0;
+            analysis()->m_messages.clear();
+        }
+        m_analysis.pop();
+
+        if (current == unionSize) {
+            // When we don't have a match for a union typed schema, we try to "guess" which
+            // particular item from the union the user tried to represent. The one with the best
+            // ranking wins.
+            if (bestRank > 0) {
+                analysis()->m_messages.append(bestErrorGuess);
+            } else {
+                analysis()->m_messages.append(Message(ErrDifferentValueExpected,
+                                                      ast->firstSourceLocation(),
+                                                      formatExpectedTypes(m_schema->validTypes()),
+                                                      QString(),
+                                                      false));
+            }
+        }
+    } else {
+        Node::accept(ast, this);
+    }
+}
+
+bool JsonCheck::proceedCheck(JsonValue::Kind kind, const SourceLocation &location)
+{
+    if (!m_firstLoc.isValid())
+        return false;
+
+    if (!m_schema->isTypeConstrained())
+        return false;
+
+    if (!m_schema->acceptsType(JsonValue::kindToString(kind))) {
+        analysis()->m_messages.append(Message(ErrDifferentValueExpected,
+                                              location,
+                                              formatExpectedTypes(m_schema->validTypes()),
+                                              QString(),
+                                              false));
+        return false;
+    }
+
+    return true;
+}
+
+JsonCheck::AnalysisData *JsonCheck::analysis()
+{
+    return &m_analysis.top();
+}

src/libs/qmljs/jsoncheck.h

+/**************************************************************************
+**
+** This file is part of Qt Creator
+**
+** Copyright (c) 2012 Nokia Corporation and/or its subsidiary(-ies).
+**
+** Contact: Nokia Corporation (info@qt.nokia.com)
+**
+**
+** 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.
+**
+** 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.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at info@qt.nokia.com.
+**
+**************************************************************************/
+
+#ifndef JSONCHECK_H
+#define JSONCHECK_H
+
+#include "qmljs_global.h"
+
+#include <qmljs/qmljsdocument.h>
+#include <qmljs/parser/qmljsast_p.h>
+#include <qmljs/parser/qmljsastvisitor_p.h>
+#include <qmljs/qmljsstaticanalysismessage.h>
+
+#include <utils/json.h>
+
+#include <QtCore/QString>
+#include <QtCore/QSet>
+#include <QtCore/QStack>
+#include <QtCore/QList>
+
+
+namespace QmlJS {
+
+class QMLJS_EXPORT JsonCheck : public AST::Visitor
+{
+public:
+    JsonCheck(Document::Ptr doc);
+    virtual ~JsonCheck();
+
+    QList<StaticAnalysis::Message> operator()(Utils::JsonSchema *schema);
+
+private:
+    virtual bool preVisit(AST::Node *);
+    virtual void postVisit(AST::Node *);
+
+    virtual bool visit(AST::ObjectLiteral *ast);
+    virtual bool visit(AST::ArrayLiteral *ast);
+    virtual bool visit(AST::NullExpression *ast);
+    virtual bool visit(AST::TrueLiteral *ast);
+    virtual bool visit(AST::FalseLiteral *ast);
+    virtual bool visit(AST::NumericLiteral *ast);
+    virtual bool visit(AST::StringLiteral *ast);
+
+    struct AnalysisData
+    {
+        AnalysisData() : m_ranking(0), m_hasMatch(false), m_evaluatinType(false) {}
+
+        void boostRanking(int unit = 1) { m_ranking += unit; }
+
+        int m_ranking;
+        bool m_hasMatch;
+        bool m_evaluatinType;
+        QList<StaticAnalysis::Message> m_messages;
+    };
+
+    void processSchema(AST::Node *ast);
+    bool proceedCheck(Utils::JsonValue::Kind kind, const AST::SourceLocation &location);
+
+    AnalysisData *analysis();
+
+    Document::Ptr m_doc;
+    AST::SourceLocation m_firstLoc;
+    Utils::JsonSchema *m_schema;
+    QStack<AnalysisData> m_analysis;
+};
+
+} // QmlJs
+
+#endif // JSONCHECK_H

src/libs/qmljs/qmljs-lib.pri

@@ -32,7 +32,8 @@ HEADERS += \
     $$PWD/qmljscontext.h \
     $$PWD/qmljsscopechain.h \
     $$PWD/qmljsutils.h \
-    $$PWD/qmljsstaticanalysismessage.h
+    $$PWD/qmljsstaticanalysismessage.h \
+    $$PWD/jsoncheck.h
 
 SOURCES += \
     $$PWD/qmljsbind.cpp \
@@ -56,7 +57,8 @@ SOURCES += \
     $$PWD/qmljscontext.cpp \
     $$PWD/qmljsscopechain.cpp \
     $$PWD/qmljsutils.cpp \
-    $$PWD/qmljsstaticanalysismessage.cpp
+    $$PWD/qmljsstaticanalysismessage.cpp \
+    $$PWD/jsoncheck.cpp
 
 RESOURCES += \
     $$PWD/qmljs.qrc

src/libs/qmljs/qmljsstaticanalysismessage.cpp

@@ -193,6 +193,30 @@ StaticAnalysisMessages::StaticAnalysisMessages()
            tr("unintentional empty block, use ({}) for empty object literal"));
     newMsg(HintPreferNonVarPropertyType, Hint,
            tr("use %1 instead of 'var' or 'variant' to improve performance"), 1);
+    newMsg(ErrMissingRequiredProperty, Error,
+           tr("missing property '%1'"), 1);
+    newMsg(ErrObjectValueExpected, Error,
+           tr("object value expected"));
+    newMsg(ErrArrayValueExpected, Error,
+           tr("array value expected"));
+    newMsg(ErrDifferentValueExpected, Error,
+           tr("%1 value expected"), 1);
+    newMsg(ErrSmallerNumberValueExpected, Error,
+           tr("maximum number value is %1"), 1);
+    newMsg(ErrLargerNumberValueExpected, Error,
+           tr("minimum number value is %1"), 1);
+    newMsg(ErrMaximumNumberValueIsExclusive, Error,
+           tr("maximum number value is exclusive"));
+    newMsg(ErrMinimumNumberValueIsExclusive, Error,
+           tr("minimum number value is exclusive"));
+    newMsg(ErrInvalidStringValuePattern, Error,
+           tr("string value does not match required pattern"));
+    newMsg(ErrLongerStringValueExpected, Error,
+           tr("minimum string value length is %1"), 1);
+    newMsg(ErrShorterStringValueExpected, Error,
+           tr("maximum string value length is %1"), 1);
+    newMsg(ErrInvalidArrayValueLength, Error,
+           tr("%1 elements expected in array value"), 1);
 }
 
 } // anonymous namespace
@@ -208,7 +232,11 @@ Message::Message()
     : type(UnknownType), severity(Hint)
 {}
 
-Message::Message(Type type, AST::SourceLocation location, const QString &arg1, const QString &arg2)
+Message::Message(Type type,
+                 AST::SourceLocation location,
+                 const QString &arg1,
+                 const QString &arg2,
+                 bool appendTypeId)
     : location(location), type(type)
 {
     QTC_ASSERT(messages()->messages.contains(type), return);
@@ -227,7 +255,8 @@ Message::Message(Type type, AST::SourceLocation location, const QString &arg1, c
             qWarning() << "StaticAnalysis message" << type << "expects exactly two arguments";
         message = message.arg(arg1, arg2);
     }
-    message.append(QString(" (M%1)").arg(QString::number(prototype.type)));
+    if (appendTypeId)
+        message.append(QString(" (M%1)").arg(QString::number(prototype.type)));
 }
 
 bool Message::isValid() const

src/libs/qmljs/qmljsstaticanalysismessage.h

@@ -114,7 +114,19 @@ enum Type
     WarnNumberConstructor = 308,
     HintBinaryOperatorSpacing = 309,
     WarnUnintentinalEmptyBlock = 310,
-    HintPreferNonVarPropertyType = 311
+    HintPreferNonVarPropertyType = 311,
+    ErrMissingRequiredProperty = 312,
+    ErrObjectValueExpected = 313,
+    ErrArrayValueExpected = 314,
+    ErrDifferentValueExpected = 315,
+    ErrSmallerNumberValueExpected = 316,
+    ErrLargerNumberValueExpected = 317,
+    ErrMaximumNumberValueIsExclusive = 318,
+    ErrMinimumNumberValueIsExclusive = 319,
+    ErrInvalidStringValuePattern = 320,
+    ErrLongerStringValueExpected = 321,
+    ErrShorterStringValueExpected = 322,
+    ErrInvalidArrayValueLength = 323
 };
 
 class QMLJS_EXPORT Message
@@ -123,7 +135,8 @@ public:
     Message();
     Message(Type type, AST::SourceLocation location,
             const QString &arg1 = QString(),
-            const QString &arg2 = QString());
+            const QString &arg2 = QString(),
+            bool appendTypeId = true);
 
     static QList<Type> allMessageTypes();
 

src/libs/utils/json.h

+/**************************************************************************