IO: Add test for iterating over invisible objects

Add a test that checks invisible objects are iterated over by the
`IO::AbstractHierarchyIterator` class, when a suitable depsgraph is given.

No functional changes.

source/blender/blenloader/tests/blendfile_loading_base_test.h

@@ -56,9 +56,9 @@ class BlendfileLoadingBaseTest : public testing::Test {
   void blendfile_free();
 
   /* Create a depsgraph. Assumes a blend file has been loaded to this->bfile. */
-  void depsgraph_create(eEvaluationMode depsgraph_evaluation_mode);
+  virtual void depsgraph_create(eEvaluationMode depsgraph_evaluation_mode);
   /* Free the depsgraph if it's not nullptr. */
-  void depsgraph_free();
+  virtual void depsgraph_free();
 };
 
 #endif /* __BLENDFILE_LOADING_BASE_TEST_H__ */

source/blender/io/common/intern/abstract_hierarchy_iterator_test.cc

@@ -20,8 +20,11 @@
 
 #include "tests/blendfile_loading_base_test.h"
 
+#include "BKE_scene.h"
 #include "BLI_math.h"
+#include "BLO_readfile.h"
 #include "DEG_depsgraph.h"
+#include "DEG_depsgraph_build.h"
 #include "DNA_object_types.h"
 
 #include <map>
@@ -99,7 +102,7 @@ class TestingHierarchyIterator : public AbstractHierarchyIterator {
   }
 };
 
-class USDHierarchyIteratorTest : public BlendfileLoadingBaseTest {
+class AbstractHierarchyIteratorTest : public BlendfileLoadingBaseTest {
  protected:
   TestingHierarchyIterator *iterator;
 
@@ -131,7 +134,7 @@ class USDHierarchyIteratorTest : public BlendfileLoadingBaseTest {
   }
 };
 
-TEST_F(USDHierarchyIteratorTest, ExportHierarchyTest)
+TEST_F(AbstractHierarchyIteratorTest, ExportHierarchyTest)
 {
   /* Load the test blend file. */
   if (!blendfile_load("usd/usd_hierarchy_export_test.blend")) {
@@ -206,7 +209,7 @@ TEST_F(USDHierarchyIteratorTest, ExportHierarchyTest)
   EXPECT_EQ(expected_data, iterator->data_writers);
 }
 
-TEST_F(USDHierarchyIteratorTest, ExportSubsetTest)
+TEST_F(AbstractHierarchyIteratorTest, ExportSubsetTest)
 {
   // The scene has no hair or particle systems, and this is already covered by ExportHierarchyTest,
   // so not included here. Update this test when hair & particle systems are included.
@@ -317,4 +320,45 @@ TEST_F(USDHierarchyIteratorTest, ExportSubsetTest)
   EXPECT_EQ(expected_transforms, iterator->transform_writers);
   EXPECT_EQ(expected_data, iterator->data_writers);
 }
+
+/* Test class that constructs a depsgraph in such a way that it includes invisible objects. */
+class AbstractHierarchyIteratorInvisibleTest : public AbstractHierarchyIteratorTest {
+ protected:
+  void depsgraph_create(eEvaluationMode depsgraph_evaluation_mode) override
+  {
+    depsgraph = DEG_graph_new(
+        bfile->main, bfile->curscene, bfile->cur_view_layer, depsgraph_evaluation_mode);
+    DEG_graph_build_for_all_objects(
+        depsgraph, bfile->main, bfile->curscene, bfile->cur_view_layer);
+    BKE_scene_graph_update_tagged(depsgraph, bfile->main);
+  }
+};
+
+TEST_F(AbstractHierarchyIteratorInvisibleTest, ExportInvisibleTest)
+{
+  if (!blendfile_load("alembic/visibility.blend")) {
+    return;
+  }
+  depsgraph_create(DAG_EVAL_RENDER);
+  iterator_create();
+
+  iterator->iterate_and_write();
+
+  // Mapping from object name to set of export paths.
+  used_writers expected_transforms = {{"OBInvisibleAnimatedCube", {"/InvisibleAnimatedCube"}},
+                                      {"OBInvisibleCube", {"/InvisibleCube"}},
+                                      {"OBVisibleCube", {"/VisibleCube"}}};
+  EXPECT_EQ(expected_transforms, iterator->transform_writers);
+
+  used_writers expected_data = {{"OBInvisibleAnimatedCube", {"/InvisibleAnimatedCube/Cube"}},
+                                {"OBInvisibleCube", {"/InvisibleCube/Cube"}},
+                                {"OBVisibleCube", {"/VisibleCube/Cube"}}};
+
+  EXPECT_EQ(expected_data, iterator->data_writers);
+
+  // The scene has no hair or particle systems.
+  EXPECT_EQ(0, iterator->hair_writers.size());
+  EXPECT_EQ(0, iterator->particle_writers.size());
+}
+
 }  // namespace blender::io