Add API for adding groups and files.

This is a necessary feature for proper IDE support.

Change-Id: I296beb5beae514f70babf3da1b5544726e9df82e
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>

23 files changed, 932 insertions, 44 deletions

diff --git a/src/lib/api/api.pri b/src/lib/api/api.pri
index 917a54bbe..8a0c93237 100644
--- a/src/lib/api/api.pri
+++ b/src/lib/api/api.pri
@@ -2,6 +2,7 @@ HEADERS += \
     $$PWD/changeset.h \
     $$PWD/internaljobs.h \
     $$PWD/projectdata.h \
+    $$PWD/projectfileupdater.h \
     $$PWD/runenvironment.h \
     $$PWD/jobs.h \
     $$PWD/project.h \
@@ -12,6 +13,7 @@ HEADERS += \
 SOURCES += \
     $$PWD/changeset.cpp \
     $$PWD/internaljobs.cpp \
+    $$PWD/projectfileupdater.cpp \
     $$PWD/runenvironment.cpp \
     $$PWD/projectdata.cpp \
     $$PWD/jobs.cpp \
diff --git a/src/lib/api/project.cpp b/src/lib/api/project.cpp
index 41d4db29c..39ed4dc27 100644
--- a/src/lib/api/project.cpp
+++ b/src/lib/api/project.cpp
@@ -32,13 +32,18 @@
 #include "jobs.h"
 #include "projectdata.h"
 #include "projectdata_p.h"
+#include "projectfileupdater.h"
 #include "propertymap_p.h"
 #include "runenvironment.h"
 #include <buildgraph/artifact.h>
+#include <buildgraph/buildgraph.h>
 #include <buildgraph/productbuilddata.h>
 #include <buildgraph/productinstaller.h>
+#include <buildgraph/projectbuilddata.h>
+#include <buildgraph/rulesevaluationcontext.h>
 #include <buildgraph/timestampsupdater.h>
 #include <language/language.h>
+#include <language/projectresolver.h>
 #include <logging/logger.h>
 #include <logging/translator.h>
 #include <tools/cleanoptions.h>
@@ -108,6 +113,17 @@ public:
     QList<ResolvedProductPtr> internalProducts(const QList<ProductData> &products) const;
     QList<ResolvedProductPtr> allEnabledInternalProducts() const;
     ResolvedProductPtr internalProduct(const ProductData &product) const;
+    ProductData findProductData(const QString &productName) const;
+    GroupData findGroupData(const ProductData &product, const QString &groupName) const;
+
+    GroupData createGroupDataFromGroup(const GroupPtr &resolvedGroup);
+
+    void addGroup(const ProductData &product, const QString &groupName);
+    void addFiles(const ProductData &product, const GroupData &group, const QStringList &filePaths);
+    void updateInternalCodeLocations(const ResolvedProjectPtr &project,
+                                     const CodeLocation &changeLocation, int lineOffset);
+    void updateExternalCodeLocations(const ProjectData &project,
+                                     const CodeLocation &changeLocation, int lineOffset);
 
     const TopLevelProjectPtr internalProject;
     Logger logger;
@@ -220,6 +236,235 @@ ResolvedProductPtr ProjectPrivate::internalProduct(const ProductData &product) c
     return internalProductForProject(internalProject, product);
 }
 
+ProductData ProjectPrivate::findProductData(const QString &productName) const
+{
+    foreach (const ProductData &p, m_projectData.allProducts()) {
+        if (p.name() == productName)
+            return p;
+    }
+    return ProductData();
+}
+
+GroupData ProjectPrivate::findGroupData(const ProductData &product, const QString &groupName) const
+{
+    foreach (const GroupData &g, product.groups()) {
+        if (g.name() == groupName)
+            return g;
+    }
+    return GroupData();
+}
+
+GroupData ProjectPrivate::createGroupDataFromGroup(const GroupPtr &resolvedGroup)
+{
+    GroupData group;
+    group.d->name = resolvedGroup->name;
+    group.d->location = resolvedGroup->location;
+    foreach (const SourceArtifactConstPtr &sa, resolvedGroup->files)
+        group.d->filePaths << sa->absoluteFilePath;
+    if (resolvedGroup->wildcards) {
+        foreach (const SourceArtifactConstPtr &sa, resolvedGroup->wildcards->files)
+            group.d->expandedWildcards << sa->absoluteFilePath;
+    }
+    qSort(group.d->filePaths);
+    qSort(group.d->expandedWildcards);
+    group.d->properties.d->m_map = resolvedGroup->properties;
+    group.d->isEnabled = resolvedGroup->enabled;
+    group.d->isValid = true;
+    return group;
+}
+
+void ProjectPrivate::addGroup(const ProductData &product, const QString &groupName)
+{
+    if (groupName.isEmpty())
+        throw ErrorInfo(Tr::tr("Group has an empty name."));
+    if (!product.isValid())
+        throw ErrorInfo(Tr::tr("Product is invalid."));
+    const ResolvedProductPtr resolvedProduct = internalProduct(product);
+    if (!resolvedProduct)
+        throw ErrorInfo(Tr::tr("Product '%1' does not exist.").arg(product.name()));
+
+    // Guard against calls with outdated product data.
+    const ProductData currentProduct= findProductData(product.name());
+    QBS_CHECK(currentProduct.isValid());
+
+    foreach (const GroupPtr &resolvedGroup, resolvedProduct->groups) {
+        if (resolvedGroup->name == groupName) {
+            throw ErrorInfo(Tr::tr("Group '%1' already exists in product '%2'.")
+                            .arg(groupName, product.name()), resolvedGroup->location);
+        }
+    }
+
+    ProjectFileGroupInserter groupInserter(currentProduct, groupName);
+    groupInserter.apply();
+
+    m_projectData.d.detach(); // The data we already gave out must stay as it is.
+
+    updateInternalCodeLocations(internalProject, groupInserter.itemPosition(),
+                                groupInserter.lineOffset());
+    updateExternalCodeLocations(m_projectData, groupInserter.itemPosition(),
+                                groupInserter.lineOffset());
+
+    GroupPtr resolvedGroup = ResolvedGroup::create();
+    resolvedGroup->location = groupInserter.itemPosition();
+    resolvedGroup->enabled = true;
+    resolvedGroup->name = groupName;
+    resolvedGroup->properties = resolvedProduct->properties;
+    resolvedGroup->overrideTags = false;
+    resolvedProduct->groups << resolvedGroup;
+    foreach (const ProductData &newProduct, m_projectData.allProducts()) {
+        if (newProduct.name() == product.name()) {
+            newProduct.d->groups << createGroupDataFromGroup(resolvedGroup);
+            qSort(newProduct.d->groups);
+            break;
+        }
+    }
+}
+
+void ProjectPrivate::addFiles(const ProductData &product, const GroupData &group,
+                              const QStringList &filePaths)
+{
+    if (!product.isValid())
+        throw ErrorInfo(Tr::tr("Product is invalid."));
+    const ResolvedProductPtr resolvedProduct = internalProduct(product);
+    if (!resolvedProduct)
+        throw ErrorInfo(Tr::tr("Product '%1' does not exist.").arg(product.name()));
+
+    const ProductData currentProduct = findProductData(product.name());
+    QBS_CHECK(currentProduct.isValid());
+
+    GroupPtr resolvedGroup;
+    GroupData currentGroup;
+    const QString groupName = group.isValid() ? group.name() : product.name();
+    foreach (const GroupPtr &g, resolvedProduct->groups) {
+        if (g->name == groupName) {
+            resolvedGroup = g;
+            break;
+        }
+    }
+    if (!resolvedGroup)
+        throw ErrorInfo(Tr::tr("Group '%1' does not exist.").arg(groupName));
+    currentGroup = findGroupData(currentProduct, groupName);
+    QBS_CHECK(currentGroup.isValid());
+
+    if (filePaths.isEmpty())
+        return; // "No-op". Could also be defined to be an error, I guess.
+
+    if (!resolvedGroup->prefix.isEmpty())
+        throw ErrorInfo(Tr::tr("Cannot add files to a group with a prefix."));
+    QStringList absoluteFilePaths;
+    QString projectFileDir = QFileInfo(product.location().fileName()).dir().absolutePath();
+    foreach (const QString &filePath, filePaths) {
+        const QString absPath = QDir::cleanPath(FileInfo::resolvePath(projectFileDir,
+                                                                      filePath));
+        if (absoluteFilePaths.contains(absPath))
+            throw ErrorInfo(Tr::tr("File '%1' appears more than once.").arg(absPath));
+        if (!FileInfo(absPath).exists())
+            throw ErrorInfo(Tr::tr("File '%1' does not exist.").arg(absPath));
+        absoluteFilePaths << absPath;
+    }
+
+    // We do not check for entries in other groups, because such doublettes might be legitimate
+    // due to conditions.
+    foreach (const QString &filePath, absoluteFilePaths) {
+        foreach (const SourceArtifactConstPtr &sa, resolvedGroup->files) {
+            if (sa->absoluteFilePath == filePath) {
+                throw ErrorInfo(Tr::tr("File '%1' already exists in group '%2'.")
+                                .arg(filePath, group.name()));
+            }
+        }
+    }
+
+    ProjectFileFilesAdder adder(currentProduct, group.isValid() ? currentGroup : GroupData(),
+                                absoluteFilePaths);
+    adder.apply();
+
+    m_projectData.d.detach();
+    updateInternalCodeLocations(internalProject, adder.itemPosition(), adder.lineOffset());
+    updateExternalCodeLocations(m_projectData, adder.itemPosition(), adder.lineOffset());
+
+    QList<SourceArtifactPtr> addedSourceArtifacts;
+    foreach (const QString &file, absoluteFilePaths) {
+        const SourceArtifactPtr artifact = SourceArtifact::create();
+        artifact->absoluteFilePath = file;
+        artifact->properties = resolvedGroup->properties;
+        artifact->fileTags = resolvedGroup->fileTags;
+        artifact->overrideFileTags = resolvedGroup->overrideTags;
+        ProjectResolver::applyFileTaggers(artifact, resolvedProduct, logger);
+        addedSourceArtifacts << artifact;
+        resolvedGroup->files << artifact;
+    }
+    if (resolvedProduct->enabled) {
+        ArtifactsPerFileTagMap artifactsPerFileTag;
+        foreach (const SourceArtifactConstPtr &sa, addedSourceArtifacts) {
+            Artifact * const artifact = createArtifact(resolvedProduct, sa, logger);
+            foreach (const FileTag &ft, artifact->fileTags)
+                artifactsPerFileTag[ft] += artifact;
+        }
+        RulesEvaluationContextPtr &evalContext
+                = resolvedProduct->topLevelProject()->buildData->evaluationContext;
+        evalContext.reset(new RulesEvaluationContext(logger));
+        RulesApplicator(resolvedProduct, artifactsPerFileTag, logger).applyAllRules();
+        addTargetArtifacts(resolvedProduct, artifactsPerFileTag, logger);
+        evalContext.clear();
+    }
+    doSanityChecks(internalProject, logger);
+    currentGroup.d->filePaths << absoluteFilePaths;
+    qSort(currentGroup.d->filePaths);
+}
+
+static void updateLocationIfNecessary(CodeLocation &location, const CodeLocation &changeLocation,
+                                      int lineOffset)
+{
+    if (location.fileName() == changeLocation.fileName()
+            && location.line() >= changeLocation.line()) {
+        location = CodeLocation(location.fileName(), location.line() + lineOffset,
+                                location.column());
+    }
+}
+
+void ProjectPrivate::updateInternalCodeLocations(const ResolvedProjectPtr &project,
+        const CodeLocation &changeLocation, int lineOffset)
+{
+    updateLocationIfNecessary(project->location, changeLocation, lineOffset);
+    foreach (const ResolvedProjectPtr &subProject, project->subProjects)
+        updateInternalCodeLocations(subProject, changeLocation, lineOffset);
+    foreach (const ResolvedProductPtr &product, project->products) {
+        updateLocationIfNecessary(product->location, changeLocation, lineOffset);
+        foreach (const GroupPtr &group, product->groups)
+            updateLocationIfNecessary(group->location, changeLocation, lineOffset);
+        foreach (const RulePtr &rule, product->rules) {
+            updateLocationIfNecessary(rule->script->location, changeLocation, lineOffset);
+            foreach (const RuleArtifactPtr &artifact, rule->artifacts) {
+                for (int i = 0; i < artifact->bindings.count(); ++i) {
+                    updateLocationIfNecessary(artifact->bindings[i].location, changeLocation,
+                                              lineOffset);
+                }
+            }
+        }
+        foreach (const ResolvedTransformerConstPtr &transformer, product->transformers)
+            updateLocationIfNecessary(transformer->transform->location, changeLocation, lineOffset);
+        foreach (const ResolvedModuleConstPtr &module, product->modules) {
+            updateLocationIfNecessary(module->setupBuildEnvironmentScript->location,
+                                      changeLocation, lineOffset);
+            updateLocationIfNecessary(module->setupRunEnvironmentScript->location,
+                                      changeLocation, lineOffset);
+        }
+    }
+}
+
+void ProjectPrivate::updateExternalCodeLocations(const ProjectData &project,
+        const CodeLocation &changeLocation, int lineOffset)
+{
+    updateLocationIfNecessary(project.d->location, changeLocation, lineOffset);
+    foreach (const ProjectData &subProject, project.subProjects())
+        updateExternalCodeLocations(subProject, changeLocation, lineOffset);
+    foreach (const ProductData &product, project.products()) {
+        updateLocationIfNecessary(product.d->location, changeLocation, lineOffset);
+        foreach (const GroupData &group, product.groups())
+            updateLocationIfNecessary(group.d->location, changeLocation, lineOffset);
+    }
+}
+
 void ProjectPrivate::retrieveProjectData(ProjectData &projectData,
                                          const ResolvedProjectConstPtr &internalProject)
 {
@@ -231,23 +476,8 @@ void ProjectPrivate::retrieveProjectData(ProjectData &projectData,
         product.d->name = resolvedProduct->name;
         product.d->location = resolvedProduct->location;
         product.d->isEnabled = resolvedProduct->enabled;
-        foreach (const GroupPtr &resolvedGroup, resolvedProduct->groups) {
-            GroupData group;
-            group.d->name = resolvedGroup->name;
-            group.d->location = resolvedGroup->location;
-            foreach (const SourceArtifactConstPtr &sa, resolvedGroup->files)
-                group.d->filePaths << sa->absoluteFilePath;
-            if (resolvedGroup->wildcards) {
-                foreach (const SourceArtifactConstPtr &sa, resolvedGroup->wildcards->files)
-                    group.d->expandedWildcards << sa->absoluteFilePath;
-            }
-            qSort(group.d->filePaths);
-            qSort(group.d->expandedWildcards);
-            group.d->properties.d->m_map = resolvedGroup->properties;
-            group.d->isEnabled = resolvedGroup->enabled;
-            group.d->isValid = true;
-            product.d->groups << group;
-        }
+        foreach (const GroupPtr &resolvedGroup, resolvedProduct->groups)
+            product.d->groups << createGroupDataFromGroup(resolvedGroup);
         if (resolvedProduct->enabled) {
             QBS_CHECK(resolvedProduct->buildData);
             foreach (const Artifact * const a, resolvedProduct->buildData->targetArtifacts) {
@@ -577,4 +807,45 @@ QSet<QString> Project::buildSystemFiles() const
     return d->internalProject->buildSystemFiles;
 }
 
+/*!
+ * \brief Adds a new empty group to the given product.
+ * Returns an \c ErrorInfo object for which \c hasError() is false in case of a success
+ * and true otherwise. In the latter case, the object will have a sensible description.
+ * After calling this function, it is recommended to re-fetch the project data, as other
+ * items can be affected.
+ * \sa qbs::Project::projectData()
+ */
+ErrorInfo Project::addGroup(const ProductData &product, const QString &groupName)
+{
+    try {
+        d->addGroup(product, groupName);
+        return ErrorInfo();
+    } catch (ErrorInfo errorInfo) {
+        errorInfo.prepend(Tr::tr("Failure adding group to product."));
+        return errorInfo;
+    }
+}
+
+/*!
+ * \brief Adds the given files to the given product.
+ * If \c group is a default-constructed object, the files will be added to the product's
+ * "files" property, otherwise to the one of \c group.
+ * The file paths can be absolute or relative to the location of \c product. The project file
+ * will always contain relative paths.
+ * After calling this function, it is recommended to re-fetch the project data, as other
+ * items can be affected.
+ * \sa qbs::Project::projectData()
+ */
+ErrorInfo Project::addFiles(const ProductData &product, const GroupData &group,
+                            const QStringList &filePaths)
+{
+    try {
+        d->addFiles(product, group, filePaths);
+        return ErrorInfo();
+    } catch (ErrorInfo errorInfo) {
+        errorInfo.prepend(Tr::tr("Failure adding files to product."));
+        return errorInfo;
+    }
+}
+
 } // namespace qbs
diff --git a/src/lib/api/project.h b/src/lib/api/project.h
index 9e85bc417..11df00a08 100644
--- a/src/lib/api/project.h
+++ b/src/lib/api/project.h
@@ -49,6 +49,8 @@ class BuildJob;
 class BuildOptions;
 class CleanJob;
 class CleanOptions;
+class ErrorInfo;
+class GroupData;
 class ILogSink;
 class InstallableFile;
 class InstallJob;
@@ -120,6 +122,10 @@ public:
 
     QSet<QString> buildSystemFiles() const;
 
+    ErrorInfo addGroup(const ProductData &product, const QString &groupName);
+    ErrorInfo addFiles(const ProductData &product, const GroupData &group,
+                       const QStringList &filePaths);
+
 private:
     Project(const Internal::TopLevelProjectPtr &internalProject, const Internal::Logger &logger);
 
diff --git a/src/lib/api/projectfileupdater.cpp b/src/lib/api/projectfileupdater.cpp
new file mode 100644
index 000000000..d4c60abad
--- /dev/null
+++ b/src/lib/api/projectfileupdater.cpp
@@ -0,0 +1,305 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Build Suite.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+
+#include "projectfileupdater.h"
+
+#include "projectdata.h"
+#include "qmljsrewriter.h"
+
+#include <language/asttools.h>
+#include <logging/translator.h>
+#include <parser/qmljsast_p.h>
+#include <parser/qmljsastvisitor_p.h>
+#include <parser/qmljsengine_p.h>
+#include <parser/qmljslexer_p.h>
+#include <parser/qmljsparser_p.h>
+#include <tools/qbsassert.h>
+
+#include <QDir>
+#include <QFile>
+#include <QFileInfo>
+
+using namespace QbsQmlJS;
+using namespace AST;
+
+namespace qbs {
+namespace Internal {
+
+class ItemFinder : public Visitor
+{
+public:
+    ItemFinder(const CodeLocation &cl) : m_cl(cl), m_item(0) { }
+
+    UiObjectDefinition *item() const { return m_item; }
+
+private:
+    bool visit(UiObjectDefinition *ast)
+    {
+        if (toCodeLocation(m_cl.fileName(), ast->firstSourceLocation()) == m_cl) {
+            m_item = ast;
+            return false;
+        }
+        return true;
+    }
+
+    const CodeLocation m_cl;
+    UiObjectDefinition *m_item;
+};
+
+class FilesBindingFinder : public Visitor
+{
+public:
+    FilesBindingFinder(const UiObjectDefinition *startItem)
+        : m_startItem(startItem), m_binding(0)
+    {
+    }
+
+    UiScriptBinding *binding() const { return m_binding; }
+
+private:
+    bool visit(UiObjectDefinition *ast)
+    {
+        // We start with the direct parent of the binding, so do not descend into any
+        // other item.
+        return ast == m_startItem;
+    }
+
+    bool visit(UiScriptBinding *ast)
+    {
+        if (ast->qualifiedId->name.toString() != QLatin1String("files"))
+            return true;
+        m_binding = ast;
+        return false;
+    }
+
+    const UiObjectDefinition * const m_startItem;
+    UiScriptBinding *m_binding;
+};
+
+
+ProjectFileUpdater::ProjectFileUpdater(const QString &projectFile) : m_projectFile(projectFile)
+{
+}
+
+void ProjectFileUpdater::apply()
+{
+    QFile file(m_projectFile);
+    if (!file.open(QFile::ReadOnly)) {
+        throw ErrorInfo(Tr::tr("File '%1' cannot be opened for reading: %2")
+                        .arg(m_projectFile, file.errorString()));
+    }
+    QString content = QString::fromLocal8Bit(file.readAll());
+    file.close();
+    Engine engine;
+    Lexer lexer(&engine);
+    lexer.setCode(content, 1);
+    Parser parser(&engine);
+    if (!parser.parse()) {
+        QList<DiagnosticMessage> parserMessages = parser.diagnosticMessages();
+        if (!parserMessages.isEmpty()) {
+            ErrorInfo errorInfo;
+            errorInfo.append(Tr::tr("Failure parsing project file."));
+            foreach (const DiagnosticMessage &msg, parserMessages)
+                errorInfo.append(msg.message, toCodeLocation(file.fileName(), msg.loc));
+            throw errorInfo;
+        }
+    }
+
+    doApply(content, parser.ast());
+
+    if (!file.open(QFile::WriteOnly)) {
+        throw ErrorInfo(Tr::tr("File '%1' cannot be opened for writing: %2")
+                        .arg(m_projectFile, file.errorString()));
+    }
+    file.resize(0);
+    file.write(content.toLocal8Bit());
+}
+
+
+ProjectFileGroupInserter::ProjectFileGroupInserter(const ProductData &product,
+                                                   const QString &groupName)
+    : ProjectFileUpdater(product.location().fileName())
+    , m_product(product)
+    , m_groupName(groupName)
+{
+}
+
+void ProjectFileGroupInserter::doApply(QString &fileContent, UiProgram *ast)
+{
+    ItemFinder itemFinder(m_product.location());
+    ast->accept(&itemFinder);
+    if (!itemFinder.item()) {
+        throw ErrorInfo(Tr::tr("The project file parser failed to find the product item."),
+                        CodeLocation(projectFile()));
+    }
+
+    ChangeSet changeSet;
+    Rewriter rewriter(fileContent, &changeSet, QStringList());
+    QString groupItemString;
+    const int productItemIndentation
+            = itemFinder.item()->qualifiedTypeNameId->firstSourceLocation().startColumn - 1;
+    const int groupItemIndentation = productItemIndentation + 4;
+    const QString groupItemIndentationString = QString(groupItemIndentation, QLatin1Char(' '));
+    groupItemString += groupItemIndentationString + QLatin1String("Group {\n");
+    groupItemString += groupItemIndentationString + groupItemIndentationString
+            + QLatin1String("name: \"") + m_groupName + QLatin1String("\"\n");
+    groupItemString += groupItemIndentationString + groupItemIndentationString
+            + QLatin1String("files: []\n");
+    groupItemString += groupItemIndentationString + QLatin1Char('}');
+    rewriter.addObject(itemFinder.item()->initializer, groupItemString);
+
+    int lineOffset = 3 + 1; // Our text + a leading newline that is always added by the rewriter.
+    const QList<ChangeSet::EditOp> &editOps = changeSet.operationList();
+    QBS_CHECK(editOps.count() == 1);
+    const ChangeSet::EditOp &insertOp = editOps.first();
+    setLineOffset(lineOffset);
+
+    int insertionLine = fileContent.left(insertOp.pos1).count(QLatin1Char('\n'));
+    for (int i = 0; i < insertOp.text.count() && insertOp.text.at(i) == QLatin1Char('\n'); ++i)
+        ++insertionLine; // To account for newlines prepended by the rewriter.
+    ++insertionLine; // To account for zero-based indexing.
+    setItemPosition(CodeLocation(projectFile(), insertionLine,
+                                 groupItemIndentation + 1));
+    changeSet.apply(&fileContent);
+}
+
+ProjectFileFilesAdder::ProjectFileFilesAdder(const ProductData &product, const GroupData &group,
+                                             const QStringList &files)
+    : ProjectFileUpdater(product.location().fileName())
+    , m_product(product)
+    , m_group(group)
+    , m_files(files)
+{
+}
+
+void ProjectFileFilesAdder::doApply(QString &fileContent, UiProgram *ast)
+{
+    // Find the item containing the "files" binding.
+    ItemFinder itemFinder(m_group.isValid() ? m_group.location() : m_product.location());
+    ast->accept(&itemFinder);
+    if (!itemFinder.item()) {
+        throw ErrorInfo(Tr::tr("The project file parser failed to find the item."),
+                        CodeLocation(projectFile()));
+    }
+
+    const int itemIndentation
+            = itemFinder.item()->qualifiedTypeNameId->firstSourceLocation().startColumn - 1;
+    const int bindingIndentation = itemIndentation + 4;
+    const int arrayElemIndentation = bindingIndentation + 4;
+    QString newFilesString;
+    const QDir projectFileDir = QFileInfo(projectFile()).dir();
+    foreach (const QString &absFilePath, m_files) {
+        newFilesString += QString(arrayElemIndentation, QLatin1Char(' '));
+        newFilesString += QLatin1Char('"');
+        newFilesString += projectFileDir.relativeFilePath(absFilePath);
+        newFilesString += QLatin1Char('"');
+        newFilesString += QLatin1String(",\n");
+    }
+    newFilesString.chop(2); // Trailing comma and newline.
+
+    // Now get the binding itself.
+    FilesBindingFinder bindingFinder(itemFinder.item());
+    itemFinder.item()->accept(&bindingFinder);
+
+    ChangeSet changeSet;
+    Rewriter rewriter(fileContent, &changeSet, QStringList());
+
+    UiScriptBinding * const filesBinding = bindingFinder.binding();
+    if (filesBinding) {
+        if (filesBinding->statement->kind != Node::Kind_ExpressionStatement)
+            throw ErrorInfo(Tr::tr("JavaScript construct in source file is too complex.")); // TODO: rename, add new and concat.
+        const ExpressionStatement * const exprStatement
+                = static_cast<ExpressionStatement *>(filesBinding->statement);
+        switch (exprStatement->expression->kind) {
+        case Node::Kind_ArrayLiteral: {
+            QString filesString = QLatin1String("[\n");
+            const ElementList *elem
+                    = static_cast<ArrayLiteral *>(exprStatement->expression)->elements;
+            while (elem) {
+                const quint32 start = elem->expression->firstSourceLocation().offset;
+                const quint32 end = elem->expression->lastSourceLocation().end();
+                const QString elemRepr = fileContent.mid(start, end - start);
+                filesString += QString(arrayElemIndentation, QLatin1Char(' '));
+                filesString += elemRepr;
+                filesString += QLatin1String(",\n");
+                elem = elem->next;
+            }
+            filesString += newFilesString;
+            filesString += QLatin1Char('\n');
+            filesString += QString(bindingIndentation, QLatin1Char(' '));
+            filesString += QLatin1Char(']');
+            rewriter.changeBinding(itemFinder.item()->initializer, QLatin1String("files"),
+                                   filesString, Rewriter::ScriptBinding);
+            break;
+        }
+        case Node::Kind_StringLiteral: {
+            const QString existingElement
+                    = static_cast<StringLiteral *>(exprStatement->expression)->value.toString();
+            QString filesString = QLatin1String("[\n");
+            filesString += QString(arrayElemIndentation, QLatin1Char(' '));
+            filesString += QLatin1Char('"') + existingElement + QLatin1Char('"');
+            filesString += QLatin1String(",\n");
+            filesString += newFilesString;
+            filesString += QLatin1Char('\n');
+            filesString += QString(bindingIndentation, QLatin1Char(' '));
+            filesString += QLatin1Char(']');
+            rewriter.changeBinding(itemFinder.item()->initializer, QLatin1String("files"),
+                                   filesString, Rewriter::ScriptBinding);
+            break;
+        }
+        default:
+            qDebug("unsupported kind: %d", exprStatement->expression->kind);
+            // TODO: If it's an identifier, call "concat()".
+            throw ErrorInfo(Tr::tr("Javascript construct in source file is too complex."));
+        }
+    } else { // Can happen for the product itself, for which the "files" binding is not mandatory.
+        newFilesString.prepend(QLatin1String("[\n"));
+        newFilesString += QLatin1Char('\n');
+        newFilesString += QString(bindingIndentation, QLatin1Char(' '));
+        newFilesString += QLatin1Char(']');
+        const QString bindingString = QString(bindingIndentation, QLatin1Char(' '))
+                + QLatin1String("files");
+        rewriter.addBinding(itemFinder.item()->initializer, bindingString, newFilesString,
+                            Rewriter::ScriptBinding);
+    }
+
+    const QList<ChangeSet::EditOp> &editOps = changeSet.operationList();
+    QBS_CHECK(editOps.count() == 1);
+    const ChangeSet::EditOp &insertOp = editOps.first();
+    setLineOffset(insertOp.text.count(QLatin1Char('\n')));
+
+    const int insertionLine = fileContent.left(insertOp.pos1 + 1).count(QLatin1Char('\n')) + 2;
+    const int insertionColumn = (filesBinding ? arrayElemIndentation : bindingIndentation) + 1;
+    setItemPosition(CodeLocation(projectFile(), insertionLine, insertionColumn));
+    changeSet.apply(&fileContent);
+}
+
+
+} // namespace Internal
+} // namespace qbs
diff --git a/src/lib/api/projectfileupdater.h b/src/lib/api/projectfileupdater.h
new file mode 100644
index 000000000..a7ce351a5
--- /dev/null
+++ b/src/lib/api/projectfileupdater.h
@@ -0,0 +1,100 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the Qt Build Suite.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, 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, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+****************************************************************************/
+#ifndef QBS_PROJECTFILEUPDATER_H
+#define QBS_PROJECTFILEUPDATER_H
+
+#include "projectdata.h"
+
+#include <tools/error.h>
+#include <tools/codelocation.h>
+
+#include <QStringList>
+
+namespace QbsQmlJS { namespace AST { class UiProgram; } }
+
+namespace qbs {
+namespace Internal {
+
+class ProjectFileUpdater
+{
+public:
+    void apply();
+
+    CodeLocation itemPosition() const { return m_itemPosition; }
+    int lineOffset() const { return m_lineOffset; }
+
+protected:
+    ProjectFileUpdater(const QString &projectFile);
+
+    QString projectFile() const { return m_projectFile; }
+
+    void setLineOffset(int offset) { m_lineOffset = offset; }
+    void setItemPosition(const CodeLocation &cl) { m_itemPosition = cl; }
+
+private:
+    virtual void doApply(QString &fileContent, QbsQmlJS::AST::UiProgram *ast) = 0;
+
+    const QString m_projectFile;
+    CodeLocation m_itemPosition;
+    int m_lineOffset;
+};
+
+
+class ProjectFileGroupInserter : public ProjectFileUpdater
+{
+public:
+    ProjectFileGroupInserter(const ProductData &product, const QString &groupName);
+
+private:
+    void doApply(QString &fileContent, QbsQmlJS::AST::UiProgram *ast);
+
+    const ProductData m_product;
+    const QString m_groupName;
+};
+
+
+class ProjectFileFilesAdder : public ProjectFileUpdater
+{
+public:
+    ProjectFileFilesAdder(const ProductData &product, const GroupData &group,
+                          const QStringList &files);
+
+private:
+    void doApply(QString &fileContent, QbsQmlJS::AST::UiProgram *ast);
+
+    const ProductData m_product;
+    const GroupData m_group;
+    const QStringList m_files;
+};
+
+} // namespace Internal
+} // namespace qbs
+
+
+#endif // Include guard.
diff --git a/src/lib/language/language.h b/src/lib/language/language.h
index 334400035..f828b7b33 100644
--- a/src/lib/language/language.h
+++ b/src/lib/language/language.h
@@ -252,8 +252,8 @@ public:
 
     QString name;
     QStringList moduleDependencies;
-    ScriptFunctionConstPtr setupBuildEnvironmentScript;
-    ScriptFunctionConstPtr setupRunEnvironmentScript;
+    ScriptFunctionPtr setupBuildEnvironmentScript;
+    ScriptFunctionPtr setupRunEnvironmentScript;
 
 private:
     ResolvedModule() {}
@@ -279,13 +279,13 @@ public:
     static RulePtr create() { return RulePtr(new Rule); }
 
     ResolvedModuleConstPtr module;
-    ScriptFunctionConstPtr script;
+    ScriptFunctionPtr script;
     FileTags inputs;
     FileTags auxiliaryInputs;
     FileTags usings;
     FileTags explicitlyDependsOn;
     bool multiplex;
-    QList<RuleArtifactConstPtr> artifacts;
+    QList<RuleArtifactPtr> artifacts;
 
     // members that we don't need to save
     int ruleGraphId;
@@ -314,7 +314,7 @@ public:
     ResolvedModuleConstPtr module;
     QStringList inputs;
     QList<SourceArtifactPtr> outputs;
-    ScriptFunctionConstPtr transform;
+    ScriptFunctionPtr transform;
     FileTags explicitlyDependsOn;
 
 private:
diff --git a/src/lib/language/projectresolver.cpp b/src/lib/language/projectresolver.cpp
index 65a874d70..7de84608c 100644
--- a/src/lib/language/projectresolver.cpp
+++ b/src/lib/language/projectresolver.cpp
@@ -831,11 +831,11 @@ void ProjectResolver::postProcess(const ResolvedProductPtr &product,
 void ProjectResolver::applyFileTaggers(const ResolvedProductPtr &product) const
 {
     foreach (const SourceArtifactPtr &artifact, product->allEnabledFiles())
-        applyFileTaggers(artifact, product);
+        applyFileTaggers(artifact, product, m_logger);
 }
 
 void ProjectResolver::applyFileTaggers(const SourceArtifactPtr &artifact,
-                                       const ResolvedProductConstPtr &product) const
+        const ResolvedProductConstPtr &product, const Logger &logger)
 {
     if (!artifact->overrideFileTags || artifact->fileTags.isEmpty()) {
         const QString fileName = FileInfo::fileName(artifact->absoluteFilePath);
@@ -843,8 +843,8 @@ void ProjectResolver::applyFileTaggers(const SourceArtifactPtr &artifact,
         artifact->fileTags.unite(fileTags);
         if (artifact->fileTags.isEmpty())
             artifact->fileTags.insert(unknownFileTag());
-        if (m_logger.traceEnabled())
-            m_logger.qbsTrace() << "[PR] adding file tags " << artifact->fileTags
+        if (logger.traceEnabled())
+            logger.qbsTrace() << "[PR] adding file tags " << artifact->fileTags
                        << " to " << fileName;
     }
 }
diff --git a/src/lib/language/projectresolver.h b/src/lib/language/projectresolver.h
index 645aeba77..b23f19341 100644
--- a/src/lib/language/projectresolver.h
+++ b/src/lib/language/projectresolver.h
@@ -61,6 +61,9 @@ public:
     TopLevelProjectPtr resolve(ModuleLoaderResult &loadResult,
                                const SetupProjectParameters &setupParameters);
 
+    static void applyFileTaggers(const SourceArtifactPtr &artifact,
+            const ResolvedProductConstPtr &product, const Logger &logger);
+
 private:
     struct ProjectContext
     {
@@ -105,8 +108,6 @@ private:
     void resolveProductDependencies(ProjectContext *projectContext);
     void postProcess(const ResolvedProductPtr &product, ProjectContext *projectContext) const;
     void applyFileTaggers(const ResolvedProductPtr &product) const;
-    void applyFileTaggers(const SourceArtifactPtr &artifact,
-                          const ResolvedProductConstPtr &product) const;
     QVariantMap evaluateModuleValues(Item *item) const;
     void evaluateModuleValues(Item *item, QVariantMap *modulesMap) const;
     QVariantMap evaluateProperties(Item *item) const;
diff --git a/src/lib/lib.qbs b/src/lib/lib.qbs
index c45997744..f5d08380d 100644
--- a/src/lib/lib.qbs
+++ b/src/lib/lib.qbs
@@ -49,6 +49,8 @@ Product {
             "project.cpp",
             "projectdata.cpp",
             "projectdata_p.h",
+            "projectfileupdater.cpp",
+            "projectfileupdater.h",
             "qmljsrewriter.cpp",
             "qmljsrewriter.h",
             "propertymap_p.h",
diff --git a/src/lib/tools/fileinfo.h b/src/lib/tools/fileinfo.h
index f7de2d2a0..1f988c867 100644
--- a/src/lib/tools/fileinfo.h
+++ b/src/lib/tools/fileinfo.h
@@ -83,11 +83,11 @@ private:
 };
 
 bool removeFileRecursion(const QFileInfo &f, QString *errorMessage);
-bool copyFileRecursion(const QString &sourcePath, const QString &targetPath, bool preserveSymLinks,
-        QString *errorMessage);
 
-// FIXME: Used by tst_blackbox
+// FIXME: Used by tests.
 bool QBS_EXPORT removeDirectoryWithContents(const QString &path, QString *errorMessage);
+bool QBS_EXPORT copyFileRecursion(const QString &sourcePath, const QString &targetPath,
+                                  bool preserveSymLinks, QString *errorMessage);
 
 } // namespace Internal
 } // namespace qbs
diff --git a/tests/auto/api/testdata/project-editing/existingfile1.txt b/tests/auto/api/testdata/project-editing/existingfile1.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/existingfile1.txt
diff --git a/tests/auto/api/testdata/project-editing/existingfile2.txt b/tests/auto/api/testdata/project-editing/existingfile2.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/existingfile2.txt
diff --git a/tests/auto/api/testdata/project-editing/existingfile3.txt b/tests/auto/api/testdata/project-editing/existingfile3.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/existingfile3.txt
diff --git a/tests/auto/api/testdata/project-editing/file.cpp b/tests/auto/api/testdata/project-editing/file.cpp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/file.cpp
diff --git a/tests/auto/api/testdata/project-editing/file.h b/tests/auto/api/testdata/project-editing/file.h
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/file.h
diff --git a/tests/auto/api/testdata/project-editing/main.cpp b/tests/auto/api/testdata/project-editing/main.cpp
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/main.cpp
diff --git a/tests/auto/api/testdata/project-editing/newfile1.txt b/tests/auto/api/testdata/project-editing/newfile1.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/newfile1.txt
diff --git a/tests/auto/api/testdata/project-editing/newfile2.txt b/tests/auto/api/testdata/project-editing/newfile2.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/newfile2.txt
diff --git a/tests/auto/api/testdata/project-editing/newfile3.txt b/tests/auto/api/testdata/project-editing/newfile3.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/newfile3.txt
diff --git a/tests/auto/api/testdata/project-editing/newfile4.txt b/tests/auto/api/testdata/project-editing/newfile4.txt
new file mode 100644
index 000000000..e69de29bb
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/newfile4.txt
diff --git a/tests/auto/api/testdata/project-editing/project.qbs b/tests/auto/api/testdata/project-editing/project.qbs
new file mode 100644
index 000000000..1d7704fe6
--- /dev/null
+++ b/tests/auto/api/testdata/project-editing/project.qbs
@@ -0,0 +1,21 @@
+import qbs
+
+CppApplication {
+    Group {
+        name: "Existing Group 1"
+        files: ["existingfile1.txt"]
+    }
+    property string aFile: "existingfile2.txt"
+    Group {
+        name: "Existing Group 2"
+        files: product.aFile
+    }
+    Group {
+        name: "Existing Group 3"
+        files: {
+            var file = "existingfile3.txt";
+            return file;
+        }
+    }
+    files: "main.cpp"
+}
diff --git a/tests/auto/api/tst_api.cpp b/tests/auto/api/tst_api.cpp
index a60d4795e..1e1e883d3 100644
--- a/tests/auto/api/tst_api.cpp
+++ b/tests/auto/api/tst_api.cpp
@@ -35,7 +35,9 @@
 #include <api/project.h>
 #include <api/projectdata.h>
 #include <logging/ilogsink.h>
+#include <tools/fileinfo.h>
 #include <tools/hostosinfo.h>
+#include <tools/buildoptions.h>
 #include <tools/installoptions.h>
 #include <tools/preferences.h>
 #include <tools/setupprojectparameters.h>
@@ -44,6 +46,7 @@
 #include <QDir>
 #include <QEventLoop>
 #include <QScopedPointer>
+#include <QStringList>
 #include <QTest>
 
 class LogSink: public qbs::ILogSink
@@ -54,7 +57,22 @@ class LogSink: public qbs::ILogSink
     void doPrintMessage(qbs::LoggerLevel, const QString &, const QString &) { }
 };
 
-TestApi::TestApi() : m_logSink(new LogSink)
+class BuildDescriptionReveiver : public QObject
+{
+    Q_OBJECT
+public:
+    QString descriptions;
+
+private slots:
+    void handleDescription(const QString &, const QString &description) {
+        descriptions += description;
+    }
+};
+
+TestApi::TestApi()
+    : m_logSink(new LogSink)
+    , m_sourceDataDir(QDir::cleanPath(SRCDIR "/testdata"))
+    , m_workingDataDir(QCoreApplication::applicationDirPath() + "/../tests/auto/api/testWorkDir")
 {
 }
 
@@ -63,6 +81,14 @@ TestApi::~TestApi()
     delete m_logSink;
 }
 
+void TestApi::initTestCase()
+{
+    QString errorMessage;
+    qbs::Internal::removeDirectoryWithContents(m_workingDataDir, &errorMessage);
+    QVERIFY2(qbs::Internal::copyFileRecursion(m_sourceDataDir,
+            m_workingDataDir, false, &errorMessage), qPrintable(errorMessage));
+}
+
 static void waitForFinished(qbs::AbstractJob *job)
 {
     QEventLoop loop;
@@ -70,11 +96,160 @@ static void waitForFinished(qbs::AbstractJob *job)
     loop.exec();
 }
 
+
+void printProjectData(const qbs::ProjectData &project)
+{
+    foreach (const qbs::ProductData &p, project.products()) {
+        qDebug("    Product '%s' at %s", qPrintable(p.name()), qPrintable(p.location().toString()));
+        foreach (const qbs::GroupData &g, p.groups()) {
+            qDebug("        Group '%s' at %s", qPrintable(g.name()), qPrintable(g.location().toString()));
+            qDebug("            Files: %s", qPrintable(g.filePaths().join(QLatin1String(", "))));
+        }
+    }
+}
+
+qbs::GroupData findGroup(const qbs::ProductData &product, const QString &name)
+{
+    foreach (const qbs::GroupData &g, product.groups()) {
+        if (g.name() == name)
+            return g;
+    }
+    return qbs::GroupData();
+}
+
+void TestApi::changeContent()
+{
+    qbs::SetupProjectParameters setupParams = defaultSetupParameters();
+    setupParams.setProjectFilePath(QDir::cleanPath(m_workingDataDir +
+        "/project-editing/project.qbs"));
+    QScopedPointer<qbs::SetupProjectJob> job(qbs::Project::setupProject(setupParams,
+                                                                        m_logSink, 0));
+    waitForFinished(job.data());
+    QVERIFY2(!job->error().hasError(), qPrintable(job->error().toString()));
+    qbs::Project project = job->project();
+    qbs::ProjectData projectData = project.projectData();
+    QCOMPARE(projectData.allProducts().count(), 1);
+    qbs::ProductData product = projectData.allProducts().first();
+    QCOMPARE(product.groups().count(), 4);
+
+    // Error handling: Invalid product.
+    qbs::ErrorInfo errorInfo = project.addGroup(qbs::ProductData(), "blubb");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY(errorInfo.toString().contains("invalid"));
+
+    // Error handling: Empty group name.
+    errorInfo = project.addGroup(product, QString());
+    QVERIFY(errorInfo.hasError());
+    QVERIFY(errorInfo.toString().contains("empty"));
+
+    errorInfo = project.addGroup(product, "New Group 1");
+    QVERIFY2(!errorInfo.hasError(), qPrintable(errorInfo.toString()));
+
+    errorInfo = project.addGroup(product, "New Group 2");
+    QVERIFY2(!errorInfo.hasError(), qPrintable(errorInfo.toString()));
+
+    // Error handling: Group already inserted.
+    errorInfo = project.addGroup(product, "New Group 1");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY(errorInfo.toString().contains("already"));
+
+    // Error handling: Add list of files with double entries.
+    errorInfo = project.addFiles(product, qbs::GroupData(), QStringList() << "file.cpp"
+                                 << "file.cpp");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY2(errorInfo.toString().contains("more than once"), qPrintable(errorInfo.toString()));
+
+    // Add files to empty array literal.
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    QCOMPARE(product.groups().count(), 6);
+    qbs::GroupData group = findGroup(product, "New Group 1");
+    QVERIFY(group.isValid());
+    errorInfo = project.addFiles(product, group, QStringList() << "file.h" << "file.cpp");
+    QVERIFY2(!errorInfo.hasError(), qPrintable(errorInfo.toString()));
+
+    // Error handling: Add the same file again.
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    QCOMPARE(product.groups().count(), 6);
+    group = findGroup(product, "New Group 1");
+    QVERIFY(group.isValid());
+    errorInfo = project.addFiles(product, group, QStringList() << "file.cpp");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY2(errorInfo.toString().contains("already"), qPrintable(errorInfo.toString()));
+
+    // Add file to non-empty array literal.
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    group = findGroup(product, "Existing Group 1");
+    QVERIFY(group.isValid());
+    errorInfo = project.addFiles(product, group, QStringList() << "newfile1.txt");
+    QVERIFY2(!errorInfo.hasError(), qPrintable(errorInfo.toString()));
+
+    // Add files to list represented as a single string.
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    errorInfo = project.addFiles(product, qbs::GroupData(), QStringList() << "newfile2.txt");
+    QVERIFY2(!errorInfo.hasError(), qPrintable(errorInfo.toString()));
+
+    // Add files to list represented as an identifier (not yet implmented).
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    group = findGroup(product, "Existing Group 2");
+    QVERIFY(group.isValid());
+    errorInfo = project.addFiles(product, group, QStringList() << "newfile3.txt");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY2(errorInfo.toString().contains("complex"), qPrintable(errorInfo.toString()));
+
+    // Add files to list represented as a block of code (not yet implemented).
+    projectData = project.projectData();
+    QVERIFY(projectData.products().count() == 1);
+    product = projectData.products().first();
+    group = findGroup(product, "Existing Group 3");
+    QVERIFY(group.isValid());
+    errorInfo = project.addFiles(product, group, QStringList() << "newfile4.txt");
+    QVERIFY(errorInfo.hasError());
+    QVERIFY2(errorInfo.toString().contains("complex"), qPrintable(errorInfo.toString()));
+
+    // Check whether building will take the newly added cpp file into account.
+    // This must not be moved below the re-resolving test!!!
+    qbs::BuildOptions buildOptions;
+    buildOptions.setDryRun(true);
+    m_logSink->setLogLevel(qbs::LoggerMaxLevel);
+    BuildDescriptionReveiver rcvr;
+    const QScopedPointer<qbs::BuildJob> buildJob(project.buildAllProducts(buildOptions, this));
+    connect(buildJob.data(), SIGNAL(reportCommandDescription(QString, QString)), &rcvr,
+            SLOT(handleDescription(QString,QString)));
+    waitForFinished(buildJob.data());
+    QVERIFY2(!buildJob->error().hasError(), qPrintable(buildJob->error().toString()));
+    QVERIFY(rcvr.descriptions.contains("compiling file.cpp"));
+
+    // Now check whether the data updates were done correctly.
+    projectData = project.projectData();
+    job.reset(qbs::Project::setupProject(setupParams, m_logSink, 0));
+    waitForFinished(job.data());
+    QVERIFY2(!job->error().hasError(), qPrintable(job->error().toString()));
+    const qbs::ProjectData newProjectData = job->project().projectData();
+    const bool projectDataMatches = newProjectData == projectData;
+    if (!projectDataMatches) {
+        qDebug("This is the assumed project:");
+        printProjectData(projectData);
+        qDebug("This is the actual project:");
+        printProjectData(newProjectData);
+    }
+    QVERIFY(projectDataMatches); // Will fail if e.g. code locations don't match.
+}
+
 void TestApi::disabledInstallGroup()
 {
     qbs::SetupProjectParameters setupParams = defaultSetupParameters();
-    setupParams.setProjectFilePath(QDir::cleanPath(QLatin1String(SRCDIR "/testdata"
-        "/disabled_install_group/project.qbs")));
+    setupParams.setProjectFilePath(QDir::cleanPath(m_workingDataDir +
+        "/disabled_install_group/project.qbs"));
     QScopedPointer<qbs::SetupProjectJob> job(qbs::Project::setupProject(setupParams,
                                                                         m_logSink, 0));
     waitForFinished(job.data());
@@ -95,8 +270,8 @@ void TestApi::disabledInstallGroup()
 void TestApi::fileTagsFilterOverride()
 {
     qbs::SetupProjectParameters setupParams = defaultSetupParameters();
-    setupParams.setProjectFilePath(QDir::cleanPath(QLatin1String(SRCDIR "/testdata"
-        "/filetagsfilter_override/project.qbs")));
+    setupParams.setProjectFilePath(QDir::cleanPath(m_workingDataDir +
+        "/filetagsfilter_override/project.qbs"));
     QScopedPointer<qbs::SetupProjectJob> job(qbs::Project::setupProject(setupParams,
                                                                         m_logSink, 0));
     waitForFinished(job.data());
@@ -176,7 +351,7 @@ void TestApi::nonexistingProjectPropertyFromProduct()
 {
     qbs::SetupProjectParameters setupParams = defaultSetupParameters();
     const QString projectDir
-            = QDir::cleanPath(QLatin1String(SRCDIR "/testdata/nonexistingprojectproperties"));
+            = QDir::cleanPath(m_workingDataDir + "/nonexistingprojectproperties");
     const QString topLevelProjectFile = projectDir + QLatin1String("/invalidaccessfromproduct.qbs");
     setupParams.setProjectFilePath(topLevelProjectFile);
     QScopedPointer<qbs::SetupProjectJob> job(qbs::Project::setupProject(setupParams,
@@ -191,8 +366,7 @@ void TestApi::nonexistingProjectPropertyFromProduct()
 void TestApi::nonexistingProjectPropertyFromCommandLine()
 {
     qbs::SetupProjectParameters setupParams = defaultSetupParameters();
-    const QString projectDir
-            = QDir::cleanPath(QLatin1String(SRCDIR "/testdata/nonexistingprojectproperties"));
+    const QString projectDir = QDir::cleanPath(m_workingDataDir + "/nonexistingprojectproperties");
     const QString topLevelProjectFile = projectDir + QLatin1String("/project.qbs");
     setupParams.setProjectFilePath(topLevelProjectFile);
     QVariantMap projectProperties;
@@ -227,3 +401,5 @@ qbs::SetupProjectParameters TestApi::defaultSetupParameters() const
 }
 
 QTEST_MAIN(TestApi)
+
+#include "tst_api.moc"
diff --git a/tests/auto/api/tst_api.h b/tests/auto/api/tst_api.h
index 707ccf85e..ffeff6922 100644
--- a/tests/auto/api/tst_api.h
+++ b/tests/auto/api/tst_api.h
@@ -32,10 +32,9 @@
 
 #include <QObject>
 
-namespace qbs {
-class ILogSink;
-class SetupProjectParameters;
-}
+namespace qbs { class SetupProjectParameters; }
+
+class LogSink;
 
 class TestApi : public QObject
 {
@@ -46,6 +45,9 @@ public:
     ~TestApi();
 
 private slots:
+    void initTestCase();
+
+    void changeContent();
     void disabledInstallGroup();
     void fileTagsFilterOverride();
     void installableFiles();
@@ -56,7 +58,9 @@ private slots:
 private:
     qbs::SetupProjectParameters defaultSetupParameters() const;
 
-    qbs::ILogSink * const m_logSink;
+    LogSink * const m_logSink;
+    const QString m_sourceDataDir;
+    const QString m_workingDataDir;
 };
 
 #endif // Include guard.