Add LayerUtils export import test

test/qml/tst_layerUtils.qml

@@ -0,0 +1,97 @@
+import QtQuick
+import QtTest
+import org.qgis
+import org.qfield
+
+TestCase {
+  name: "LayerUtils"
+
+  /**
+   * Creates a memory layer with two fields and three features, then exercises
+   * LayerUtils.saveVectorLayerAs and LayerUtils.loadVectorLayer end-to-end.
+   *
+   * Verifies that:
+   * Exporting with no filter writes every feature and returns the final path
+   * A filter expression restricts the exported subset
+   * Attributes survive the export / reload round trip
+   * Features can be iterated from a loaded layer and copied into a target
+   * layer via LayerUtils.addFeature
+   */
+
+  function test_00_exportImportWorkflow() {
+    //Create source layer and register it
+    let sourceFields = FeatureUtils.createFields([FeatureUtils.createField("id", FeatureUtils.Int), FeatureUtils.createField("label", FeatureUtils.String)]);
+    let sourceLayer = LayerUtils.createMemoryLayer("LayerUtilsSource", sourceFields, Qgis.WkbType.Point, CoordinateReferenceSystemUtils.wgs84Crs());
+    verify(sourceLayer !== null, "Source layer must be created");
+    ProjectUtils.addMapLayer(qgisProject, sourceLayer);
+
+    //Seed three features
+    sourceLayer.startEditing();
+    for (let i = 0; i < 3; ++i) {
+      let feature = FeatureUtils.createBlankFeature(sourceLayer.fields, GeometryUtils.createGeometryFromWkt("POINT(" + i + " " + i + ")"));
+      feature.setAttribute(sourceLayer.fields.indexFromName("id"), i + 1);
+      feature.setAttribute(sourceLayer.fields.indexFromName("label"), "row-" + (i + 1));
+      verify(LayerUtils.addFeature(sourceLayer, feature), "Feature insertion failed");
+    }
+    sourceLayer.commitChanges();
+
+    //Export every feature
+    const allPath = LayerUtils.saveVectorLayerAs(sourceLayer, qgisProject.homePath + "/layerutils-export-all.gpkg", "", "");
+    verify(allPath !== "", "Export with empty filter must return a final path");
+    let exportedLayer = LayerUtils.loadVectorLayer(allPath, "LayerUtilsExportAllReload", "ogr");
+    verify(exportedLayer.isValid, "Reloaded export must be valid");
+    let allCount = 0;
+    let allIt = LayerUtils.createFeatureIterator(exportedLayer);
+    while (allIt.hasNext()) {
+      allIt.next();
+      ++allCount;
+    }
+    allIt.close();
+    compare(allCount, 3);
+
+    // Export a filtered subset
+    const filteredPath = LayerUtils.saveVectorLayerAs(sourceLayer, qgisProject.homePath + "/layerutils-export-filtered.gpkg", "", "\"id\" >= 2");
+    verify(filteredPath !== "", "Filtered export must return a final path");
+    let exportedFilteredLayer = LayerUtils.loadVectorLayer(filteredPath, "LayerUtilsExportFilteredReload", "ogr");
+    verify(exportedFilteredLayer.isValid, "Reloaded filtered export must be valid");
+    let filteredCount = 0;
+    let filteredIt = LayerUtils.createFeatureIterator(exportedFilteredLayer);
+    while (filteredIt.hasNext()) {
+      filteredIt.next();
+      ++filteredCount;
+    }
+    filteredIt.close();
+    compare(filteredCount, 2);
+
+    // Check a single feature attributes
+    let it = LayerUtils.createFeatureIteratorFromExpression(exportedLayer, "\"id\" = 2");
+    verify(it.hasNext(), "Reloaded export must contain id=2");
+    compare(it.next().attribute("label"), "row-2");
+    it.close();
+
+    // Import: iterate the loaded layer and copy features into a target layer
+    let targetFields = FeatureUtils.createFields([FeatureUtils.createField("id", FeatureUtils.Int), FeatureUtils.createField("label", FeatureUtils.String)]);
+    let targetLayer = LayerUtils.createMemoryLayer("LayerUtilsTarget", targetFields, Qgis.WkbType.Point, CoordinateReferenceSystemUtils.wgs84Crs());
+    verify(targetLayer !== null, "Target layer must be created");
+    ProjectUtils.addMapLayer(qgisProject, targetLayer);
+    targetLayer.startEditing();
+    let sourceIt = LayerUtils.createFeatureIterator(exportedLayer);
+    while (sourceIt.hasNext()) {
+      let sourceFeature = sourceIt.next();
+      let copy = FeatureUtils.createBlankFeature(targetLayer.fields, sourceFeature.geometry);
+      copy.setAttribute(targetLayer.fields.indexFromName("id"), sourceFeature.attribute("id"));
+      copy.setAttribute(targetLayer.fields.indexFromName("label"), sourceFeature.attribute("label"));
+      verify(LayerUtils.addFeature(targetLayer, copy), "Imported feature insertion failed");
+    }
+    sourceIt.close();
+    targetLayer.commitChanges();
+    let targetCount = 0;
+    let targetIt = LayerUtils.createFeatureIterator(targetLayer);
+    while (targetIt.hasNext()) {
+      targetIt.next();
+      ++targetCount;
+    }
+    targetIt.close();
+    compare(targetCount, 3);
+  }
+}