Processing: Add Fix Geometry algorithm and test: Area

Porting area fix from geometry checker to processing

src/analysis/CMakeLists.txt

@@ -64,6 +64,7 @@ set(QGIS_ANALYSIS_SRCS
   processing/qgsalgorithmcheckgeometryangle.cpp
   processing/qgsalgorithmfixgeometryangle.cpp
   processing/qgsalgorithmcheckgeometryarea.cpp
+  processing/qgsalgorithmfixgeometryarea.cpp
   processing/qgsalgorithmclip.cpp
   processing/qgsalgorithmconcavehull.cpp
   processing/qgsalgorithmconditionalbranch.cpp

src/analysis/processing/qgsalgorithmfixgeometryarea.cpp

@@ -0,0 +1,292 @@
+/***************************************************************************
+                        qgsalgorithmfixgeometryarea.cpp
+                        ---------------------
+   begin                : June 2024
+   copyright            : (C) 2024 by Jacky Volpes
+   email                : jacky dot volpes at oslandia dot com
+***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#include "qgsalgorithmfixgeometryarea.h"
+#include "qgsgeometryareacheck.h"
+#include "qgsvectordataproviderfeaturepool.h"
+#include "qgsgeometrycheckerror.h"
+#include "qgsvectorfilewriter.h"
+
+///@cond PRIVATE
+
+auto QgsFixGeometryAreaAlgorithm::name() const -> QString
+{
+  return QStringLiteral( "fixgeometryarea" );
+}
+
+auto QgsFixGeometryAreaAlgorithm::displayName() const -> QString
+{
+  return QObject::tr( "Fix geometry (Area)" );
+}
+
+auto QgsFixGeometryAreaAlgorithm::tags() const -> QStringList
+{
+  return QObject::tr( "merge,polygons,neighbor,fix,area" ).split( ',' );
+}
+
+auto QgsFixGeometryAreaAlgorithm::group() const -> QString
+{
+  return QObject::tr( "Fix geometry" );
+}
+
+auto QgsFixGeometryAreaAlgorithm::groupId() const -> QString
+{
+  return QStringLiteral( "fixgeometry" );
+}
+
+auto QgsFixGeometryAreaAlgorithm::shortHelpString() const -> QString
+{
+  return QObject::tr( "This algorithm merges neighboring polygons according to the chosen method, "
+                      "based on an error layer from the check area algorithm." );
+}
+
+auto QgsFixGeometryAreaAlgorithm::createInstance() const -> QgsFixGeometryAreaAlgorithm *
+{
+  return new QgsFixGeometryAreaAlgorithm();
+}
+
+void QgsFixGeometryAreaAlgorithm::initAlgorithm( const QVariantMap &configuration )
+{
+  Q_UNUSED( configuration )
+
+  // Inputs
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "INPUT" ), QObject::tr( "Input layer" ),
+                QList< int >() << static_cast<int>( Qgis::ProcessingSourceType::VectorPolygon ) )
+              );
+  addParameter( new QgsProcessingParameterFeatureSource( QStringLiteral( "ERRORS" ), QObject::tr( "Errors layer" ),
+                QList< int >() << static_cast<int>( Qgis::ProcessingSourceType::VectorPoint ) )
+              );
+
+  // Specific inputs for this check
+  QStringList methods;
+  {
+    // const QVariantMap config;
+    // QgsGeometryCheckContext *context;  //!\ uninitialized context to retrieve resolution methods ontly (which should perhaps be a static method?)
+    QList<QgsGeometryCheckResolutionMethod> checkMethods = QgsGeometryAreaCheck( nullptr, QVariantMap() ).availableResolutionMethods();
+    std::transform( checkMethods.cbegin(), checkMethods.cend() - 2, std::inserter( methods, methods.begin() ),
+    []( const QgsGeometryCheckResolutionMethod & checkMethod ) { return checkMethod.name(); } );
+  }
+  addParameter( new QgsProcessingParameterEnum( QStringLiteral( "METHOD" ), QObject::tr( "Method" ), methods ) );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "MERGE_ATTRIBUTE" ), QObject::tr( "Field to consider when merging polygons with the identical attribue method" ),
+                  QString(), QStringLiteral( "INPUT" ),
+                  Qgis::ProcessingFieldParameterDataType::Any, false, true )
+              );
+
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "UNIQUE_ID" ), QObject::tr( "Field of original feature unique identifier" ),
+                  QStringLiteral( "id" ), QStringLiteral( "ERRORS" ) )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "PART_IDX" ), QObject::tr( "Field of part index" ),
+                  QStringLiteral( "gc_partidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "RING_IDX" ), QObject::tr( "Field of ring index" ),
+                  QStringLiteral( "gc_ringidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric )
+              );
+  addParameter( new QgsProcessingParameterField(
+                  QStringLiteral( "VERTEX_IDX" ), QObject::tr( "Field of vertex index" ),
+                  QStringLiteral( "gc_vertidx" ), QStringLiteral( "ERRORS" ),
+                  Qgis::ProcessingFieldParameterDataType::Numeric )
+              );
+
+  // Outputs
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "OUTPUT" ), QObject::tr( "Output layer" ), Qgis::ProcessingSourceType::VectorPolygon ) );
+  addParameter( new QgsProcessingParameterFeatureSink( QStringLiteral( "REPORT" ), QObject::tr( "Report layer" ), Qgis::ProcessingSourceType::VectorPoint ) );
+
+  std::unique_ptr< QgsProcessingParameterNumber > tolerance = std::make_unique< QgsProcessingParameterNumber >( QStringLiteral( "TOLERANCE" ),
+      QObject::tr( "Tolerance" ), Qgis::ProcessingNumberParameterType::Integer, 8, false, 1, 13 );
+  tolerance->setFlags( tolerance->flags() | Qgis::ProcessingParameterFlag::Advanced );
+  addParameter( tolerance.release() );
+}
+
+auto QgsFixGeometryAreaAlgorithm::processAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) -> QVariantMap
+{
+  const std::unique_ptr< QgsProcessingFeatureSource > input( parameterAsSource( parameters, QStringLiteral( "INPUT" ), context ) );
+  if ( !input )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "INPUT" ) ) );
+
+  const std::unique_ptr< QgsProcessingFeatureSource > errors( parameterAsSource( parameters, QStringLiteral( "ERRORS" ), context ) );
+  if ( !errors )
+    throw QgsProcessingException( invalidSourceError( parameters, QStringLiteral( "ERRORS" ) ) );
+
+  QgsProcessingMultiStepFeedback multiStepFeedback( 2, feedback );
+
+  const QString featIdFieldName = parameterAsString( parameters, QStringLiteral( "UNIQUE_ID" ), context );
+  const QString partIdxFieldName = parameterAsString( parameters, QStringLiteral( "PART_IDX" ), context );
+  const QString ringIdxFieldName = parameterAsString( parameters, QStringLiteral( "RING_IDX" ), context );
+  const QString vertexIdxFieldName = parameterAsString( parameters, QStringLiteral( "VERTEX_IDX" ), context );
+
+  // Specific inputs for this check
+  const QString mergeAttributeName = parameterAsString( parameters, QStringLiteral( "MERGE_ATTRIBUTE" ), context );
+  const int method = parameterAsEnum( parameters, QStringLiteral( "METHOD" ), context );
+
+  // Verify that input fields exists
+  if ( errors->fields().indexFromName( featIdFieldName ) == -1 )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not exist in errors layer." ).arg( featIdFieldName ) );
+  if ( errors->fields().indexFromName( partIdxFieldName ) == -1 )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not exist in errors layer." ).arg( partIdxFieldName ) );
+  if ( errors->fields().indexFromName( ringIdxFieldName ) == -1 )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not exist in errors layer." ).arg( ringIdxFieldName ) );
+  if ( errors->fields().indexFromName( vertexIdxFieldName ) == -1 )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not exist in errors layer." ).arg( vertexIdxFieldName ) );
+  int inputIdFieldIndex = input->fields().indexFromName( featIdFieldName );
+  if ( inputIdFieldIndex == -1 )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not exist in input layer." ).arg( featIdFieldName ) );
+
+  QgsField inputFeatIdField = input->fields().at( inputIdFieldIndex );
+  if ( inputFeatIdField.type() != errors->fields().at( errors->fields().indexFromName( featIdFieldName ) ).type() )
+    throw QgsProcessingException( QObject::tr( "Field %1 does not have the same type than in errors layer." ).arg( featIdFieldName ) );
+
+  QString dest_output;
+  const std::unique_ptr< QgsFeatureSink > sink_output( parameterAsSink( parameters, QStringLiteral( "OUTPUT" ), context, dest_output, input->fields(), input->wkbType(), input->sourceCrs() ) );
+  if ( !sink_output )
+    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "OUTPUT" ) ) );
+
+  QString dest_report;
+  QgsFields reportFields = errors->fields();
+  reportFields.append( QgsField( QStringLiteral( "report" ), QMetaType::QString ) );
+  reportFields.append( QgsField( QStringLiteral( "error_fixed" ), QMetaType::Bool ) );
+  const std::unique_ptr< QgsFeatureSink > sink_report( parameterAsSink( parameters, QStringLiteral( "REPORT" ), context, dest_report, reportFields, errors->wkbType(), errors->sourceCrs() ) );
+  if ( !sink_report )
+    throw QgsProcessingException( invalidSinkError( parameters, QStringLiteral( "REPORT" ) ) );
+
+  const QgsProject *project = QgsProject::instance();
+  std::unique_ptr<QgsGeometryCheckContext> checkContext = std::make_unique<QgsGeometryCheckContext>( mTolerance, input->sourceCrs(), project->transformContext(), project );
+  QStringList messages;
+  QVariantMap configurationCheck;
+
+  // maximum limit, we know that every feature to process is an error (otherwise it is not treated and marked as obsolete)
+  configurationCheck.insert( "areaThreshold", std::numeric_limits<double>::max() );
+  const QgsGeometryAreaCheck check( checkContext.get(), configurationCheck );
+
+  QgsVectorLayer *fixedLayer = input->materialize( QgsFeatureRequest() );
+  std::unique_ptr<QgsFeaturePool> featurePool = std::make_unique<QgsVectorDataProviderFeaturePool>( fixedLayer, false );
+  QMap<QString, QgsFeaturePool *> featurePools;
+  featurePools.insert( fixedLayer->id(), featurePool.get() );
+
+  QMap<QString, int> attributeIndex;
+  if ( method == QgsGeometryAreaCheck::ResolutionMethod::MergeIdenticalAttribute )
+  {
+    if ( mergeAttributeName.isEmpty() )
+      throw QgsProcessingException( QObject::tr( "Merge field to merge polygons with identical attribute method is empty" ) );
+    if ( !fixedLayer->fields().names().contains( mergeAttributeName ) )
+      throw QgsProcessingException( QObject::tr( "Merge field %1 does not exist in input layer" ).arg( mergeAttributeName ) );
+    attributeIndex.insert( fixedLayer->id(), fixedLayer->fields().indexOf( mergeAttributeName ) );
+  }
+
+  QgsFeature errorFeature, inputFeature, testDuplicateIdFeature;
+  QgsFeatureIterator errorFeaturesIt = errors->getFeatures();
+  QList<QgsGeometryCheck::Changes> changesList;
+  QgsFeature reportFeature;
+  reportFeature.setFields( reportFields );
+  long long progression = 0;
+  long long totalProgression = errors->featureCount();
+  multiStepFeedback.setCurrentStep( 1 );
+  multiStepFeedback.setProgressText( QObject::tr( "Fixing errors..." ) );
+  while ( errorFeaturesIt.nextFeature( errorFeature ) )
+  {
+    progression++;
+    multiStepFeedback.setProgress( static_cast<double>( static_cast<long double>( progression ) / totalProgression ) * 100 );
+    reportFeature.setGeometry( errorFeature.geometry() );
+
+    QVariant attr = errorFeature.attribute( featIdFieldName );
+    if ( !attr.isValid() || attr.isNull() )
+      throw QgsProcessingException( QObject::tr( "NULL or invalid value found in unique field %1" ).arg( featIdFieldName ) );
+
+    QString idValue = errorFeature.attribute( featIdFieldName ).toString();
+    if ( inputFeatIdField.type() == QMetaType::QString )
+      idValue = "'" + idValue + "'";
+
+    QgsFeatureIterator it = fixedLayer->getFeatures( QgsFeatureRequest().setFilterExpression( "\"" + featIdFieldName + "\" = " + idValue ) );
+    if ( !it.nextFeature( inputFeature ) || !inputFeature.isValid() )
+      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Source feature not found or invalid" ) << false );
+
+    else if ( it.nextFeature( testDuplicateIdFeature ) )
+      throw QgsProcessingException( QObject::tr( "More than one feature found in input layer with value %1 in unique field %2" ).arg( idValue ).arg( featIdFieldName ) );
+
+    else if ( inputFeature.geometry().isNull() )
+      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Feature geometry is null" ) << false );
+
+    else if ( QgsGeometryCheckerUtils::getGeomPart( inputFeature.geometry().constGet(), errorFeature.attribute( partIdxFieldName ).toInt() ) == nullptr )
+      reportFeature.setAttributes( errorFeature.attributes() << QObject::tr( "Feature geometry part is null" ) << false );
+
+    else
+    {
+      QgsGeometryCheckError checkError = QgsGeometryCheckError(
+                                           &check,
+                                           QgsGeometryCheckerUtils::LayerFeature( featurePool.get(), inputFeature, checkContext.get(), false ),
+                                           errorFeature.geometry().asPoint(),
+                                           QgsVertexId(
+                                             errorFeature.attribute( partIdxFieldName ).toInt(),
+                                             errorFeature.attribute( ringIdxFieldName ).toInt(),
+                                             errorFeature.attribute( vertexIdxFieldName ).toInt()
+                                           )
+                                         );
+      for ( auto changes : changesList )
+        checkError.handleChanges( changes );
+
+      QgsGeometryCheck::Changes changes;
+      check.fixError( featurePools, &checkError, method, attributeIndex, changes );
+      changesList << changes;
+      reportFeature.setAttributes( errorFeature.attributes() << checkError.resolutionMessage() << ( checkError.status() == QgsGeometryCheckError::StatusFixed ) );
+    }
+
+    if ( !sink_report->addFeature( reportFeature, QgsFeatureSink::FastInsert ) )
+      throw QgsProcessingException( writeFeatureError( sink_report.get(), parameters, QStringLiteral( "REPORT" ) ) );
+
+  }
+  multiStepFeedback.setProgress( 100 );
+
+  progression = 0;
+  totalProgression = fixedLayer->featureCount();
+  multiStepFeedback.setCurrentStep( 2 );
+  multiStepFeedback.setProgressText( QObject::tr( "Exporting fixed layer..." ) );
+  QgsFeature fixedFeature;
+  QgsFeatureIterator fixedFeaturesIt = fixedLayer->getFeatures();
+  while ( fixedFeaturesIt.nextFeature( fixedFeature ) )
+  {
+    progression++;
+    multiStepFeedback.setProgress( static_cast<double>( static_cast<long double>( progression ) / totalProgression ) * 100 );
+    if ( !sink_output->addFeature( fixedFeature, QgsFeatureSink::FastInsert ) )
+      throw QgsProcessingException( writeFeatureError( sink_output.get(), parameters, QStringLiteral( "OUTPUT" ) ) );
+  }
+  multiStepFeedback.setProgress( 100 );
+
+  QVariantMap outputs;
+  outputs.insert( QStringLiteral( "OUTPUT" ), dest_output );
+  outputs.insert( QStringLiteral( "REPORT" ), dest_report );
+
+  return outputs;
+}
+
+auto QgsFixGeometryAreaAlgorithm::prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback * ) -> bool
+{
+  mTolerance = parameterAsInt( parameters, QStringLiteral( "TOLERANCE" ), context );
+
+  return true;
+}
+
+auto QgsFixGeometryAreaAlgorithm::flags() const -> Qgis::ProcessingAlgorithmFlags
+{
+  return QgsProcessingAlgorithm::flags() | Qgis::ProcessingAlgorithmFlag::NoThreading;
+}
+
+///@endcond

src/analysis/processing/qgsalgorithmfixgeometryarea.h

@@ -0,0 +1,55 @@
+/***************************************************************************
+                        qgsalgorithmfixgeometryarea.h
+                        ---------------------
+   begin                : June 2024
+   copyright            : (C) 2024 by Jacky Volpes
+   email                : jacky dot volpes at oslandia dot com
+***************************************************************************/
+
+/***************************************************************************
+ *                                                                         *
+ *   This program is free software; you can redistribute it and/or modify  *
+ *   it under the terms of the GNU General Public License as published by  *
+ *   the Free Software Foundation; either version 2 of the License, or     *
+ *   (at your option) any later version.                                   *
+ *                                                                         *
+ ***************************************************************************/
+
+#ifndef QGSALGORITHMFIXGEOMETRYAREA_H
+#define QGSALGORITHMFIXGEOMETRYAREA_H
+
+#define SIP_NO_FILE
+
+#include "qgis_sip.h"
+#include "qgsprocessingalgorithm.h"
+
+///@cond PRIVATE
+
+class QgsFixGeometryAreaAlgorithm : public QgsProcessingAlgorithm
+{
+  public:
+
+    QgsFixGeometryAreaAlgorithm() = default;
+    void initAlgorithm( const QVariantMap &configuration = QVariantMap() ) override;
+    QString name() const override;
+    QString displayName() const override;
+    QStringList tags() const override;
+    QString group() const override;
+    QString groupId() const override;
+    QString shortHelpString() const override;
+    Qgis::ProcessingAlgorithmFlags flags() const override;
+    QgsFixGeometryAreaAlgorithm *createInstance() const override SIP_FACTORY;
+
+  protected:
+
+    bool prepareAlgorithm( const QVariantMap &parameters, QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+    QVariantMap processAlgorithm( const QVariantMap &parameters,
+                                  QgsProcessingContext &context, QgsProcessingFeedback *feedback ) override;
+  private:
+
+    int mTolerance{8};
+};
+
+///@endcond PRIVATE
+
+#endif // QGSALGORITHMFIXGEOMETRYAREA_H

src/analysis/processing/qgsnativealgorithms.cpp

@@ -45,6 +45,7 @@
 #include "qgsalgorithmcentroid.h"
 #include "qgsalgorithmcheckgeometryangle.h"
 #include "qgsalgorithmcheckgeometryarea.h"
+#include "qgsalgorithmfixgeometryarea.h"
 #include "qgsalgorithmclip.h"
 #include "qgsalgorithmconcavehull.h"
 #include "qgsalgorithmconditionalbranch.h"
@@ -581,6 +582,7 @@ void QgsNativeAlgorithms::loadAlgorithms()
   addAlgorithm( new QgsDensifyGeometriesByIntervalAlgorithm() );
   addAlgorithm( new QgsDensifyGeometriesByCountAlgorithm() );
   addAlgorithm( new QgsFixGeometryAngleAlgorithm() );
+  addAlgorithm( new QgsFixGeometryAreaAlgorithm() );
 }
 
 ///@endcond

tests/src/analysis/testqgsprocessingfixgeometry.cpp

@@ -35,6 +35,9 @@ class TestQgsProcessingFixGeometry: public QgsTest
     void fixAngleAlg_data();
     void fixAngleAlg();
 
+    void fixAreaAlg_data();
+    void fixAreaAlg();
+
   private:
     const QDir mDataDir{ QDir( TEST_DATA_DIR ).absoluteFilePath( QStringLiteral( "geometry_fix" ) ) };
 
@@ -175,5 +178,99 @@ void TestQgsProcessingFixGeometry::fixAngleAlg()
   }
 }
 
+void TestQgsProcessingFixGeometry::fixAreaAlg_data()
+{
+  //create a line layer that will be used in tests
+  QTest::addColumn<QStringList>( "reportList" );
+  QTest::addColumn<int>( "method" );
+
+  QTest::newRow( "Merge with longest shared edge" )
+      << ( QStringList()
+           << QStringLiteral( "Merge with neighboring polygon with longest shared edge" )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Merge with neighboring polygon with longest shared edge" )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Merge with neighboring polygon with longest shared edge" )
+           << QStringLiteral( "Merge with neighboring polygon with longest shared edge" ) )
+      << 0;
+
+  QTest::newRow( "Merge with largest area" )
+      << ( QStringList()
+           << QStringLiteral( "Merge with neighboring polygon with largest area" )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Merge with neighboring polygon with largest area" )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Failed to merge with neighbor: " )
+           << QStringLiteral( "Merge with neighboring polygon with largest area" )
+           << QStringLiteral( "Merge with neighboring polygon with largest area" ) )
+      << 1;
+
+  QTest::newRow( "Merge with identical attribute value" )
+      << ( QStringList()
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" )
+           << QStringLiteral( "Merge with neighboring polygon with identical attribute value, if any, or leave as is" ) )
+      << 2;
+}
+
+void TestQgsProcessingFixGeometry::fixAreaAlg()
+{
+
+  const QDir testDataDir( QDir( TEST_DATA_DIR ).absoluteFilePath( "geometry_checker" ) );
+  QgsVectorLayer sourceLayer = QgsVectorLayer( testDataDir.absoluteFilePath( "polygon_layer.shp" ), QStringLiteral( "polygons" ), QStringLiteral( "ogr" ) );
+  QgsVectorLayer errorsLayer = QgsVectorLayer( mDataDir.absoluteFilePath( "merge_polygons.gpkg|layername=errors_layer" ), QStringLiteral( "" ), QStringLiteral( "ogr" ) );
+  QFETCH( QStringList, reportList );
+  QFETCH( int, method );
+
+  QVERIFY( sourceLayer.isValid() );
+  QVERIFY( errorsLayer.isValid() );
+
+  const std::unique_ptr< QgsProcessingAlgorithm > alg(
+    QgsApplication::processingRegistry()->createAlgorithmById( QStringLiteral( "native:fixgeometryarea" ) )
+  );
+  QVERIFY( alg != nullptr );
+
+  QVariantMap parameters;
+  parameters.insert( QStringLiteral( "INPUT" ), QVariant::fromValue( &sourceLayer ) );
+  parameters.insert( QStringLiteral( "UNIQUE_ID" ), "id" );
+  parameters.insert( QStringLiteral( "ERRORS" ), QVariant::fromValue( &errorsLayer ) );
+  parameters.insert( QStringLiteral( "METHOD" ), method );
+  if ( method == 2 )
+    parameters.insert( QStringLiteral( "MERGE_ATTRIBUTE" ), QStringLiteral( "attr" ) );
+  parameters.insert( QStringLiteral( "OUTPUT" ), QgsProcessing::TEMPORARY_OUTPUT );
+  parameters.insert( QStringLiteral( "REPORT" ), QgsProcessing::TEMPORARY_OUTPUT );
+
+  bool ok = false;
+  QgsProcessingFeedback feedback;
+  std::unique_ptr< QgsProcessingContext > context = std::make_unique< QgsProcessingContext >();
+
+  QVariantMap results;
+  results = alg->run( parameters, *context, &feedback, &ok );
+  QVERIFY( ok );
+
+  const std::unique_ptr<QgsVectorLayer> outputLayer( qobject_cast< QgsVectorLayer * >( context->getMapLayer( results.value( QStringLiteral( "OUTPUT" ) ).toString() ) ) );
+  const std::unique_ptr<QgsVectorLayer> reportLayer( qobject_cast< QgsVectorLayer * >( context->getMapLayer( results.value( QStringLiteral( "REPORT" ) ).toString() ) ) );
+  QVERIFY( reportLayer->isValid() );
+  QVERIFY( outputLayer->isValid() );
+
+  QCOMPARE( outputLayer->featureCount(), 21 );
+  QCOMPARE( reportLayer->featureCount(), reportList.count() );
+  int idx = 1;
+  for ( QString expectedReport : reportList )
+  {
+    const QgsFeature reportFeature = reportLayer->getFeature( idx );
+    QCOMPARE( reportFeature.attribute( "report" ), expectedReport );
+    idx++;
+  }
+}
+
 QGSTEST_MAIN( TestQgsProcessingFixGeometry )
 #include "testqgsprocessingfixgeometry.moc"