diff --git a/tests/src/Mod/Part/App/CMakeLists.txt b/tests/src/Mod/Part/App/CMakeLists.txt
index ca7e8e69b4..35796ab770 100644
--- a/tests/src/Mod/Part/App/CMakeLists.txt
+++ b/tests/src/Mod/Part/App/CMakeLists.txt
@@ -4,4 +4,9 @@ target_sources(
         PRIVATE
             ${CMAKE_CURRENT_SOURCE_DIR}/TopoShape.cpp
             ${CMAKE_CURRENT_SOURCE_DIR}/TopoShapeCache.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/FeaturePartCommon.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/FeaturePartCut.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/FeaturePartFuse.cpp
+            # ${CMAKE_CURRENT_SOURCE_DIR}/FeatureFillet.cpp
+            ${CMAKE_CURRENT_SOURCE_DIR}/PartTestHelpers.cpp
 )
diff --git a/tests/src/Mod/Part/App/FeaturePartCommon.cpp b/tests/src/Mod/Part/App/FeaturePartCommon.cpp
new file mode 100644
index 0000000000..be062749bb
--- /dev/null
+++ b/tests/src/Mod/Part/App/FeaturePartCommon.cpp
@@ -0,0 +1,201 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "gtest/gtest.h"
+
+#include "Mod/Part/App/FeaturePartCommon.h"
+#include <src/App/InitApplication.h>
+
+#include "PartTestHelpers.h"
+
+class FeaturePartCommonTest: public ::testing::Test, public PartTestHelpers::PartTestHelperClass
+{
+protected:
+    static void SetUpTestSuite()
+    {
+        tests::initApplication();
+    }
+
+
+    void SetUp() override
+    {
+        createTestDoc();
+        _common = dynamic_cast<Part::Common*>(_doc->addObject("Part::Common"));
+    }
+
+    void TearDown() override
+    {}
+
+    Part::Common* _common = nullptr;  // NOLINT Can't be private in a test framework
+};
+
+TEST_F(FeaturePartCommonTest, testIntersecting)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[1]);
+
+    // Act
+    _common->execute();
+    Part::TopoShape ts = _common->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 3.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCommonTest, testNonIntersecting)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[2]);
+
+    // Act
+    _common->execute();
+    Part::TopoShape ts = _common->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_FALSE(bb.IsValid());
+    EXPECT_DOUBLE_EQ(volume, 0.0);
+}
+
+TEST_F(FeaturePartCommonTest, testTouching)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[3]);
+
+    // Act
+    _common->execute();
+    Part::TopoShape ts = _common->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_FALSE(bb.IsValid());
+    EXPECT_DOUBLE_EQ(volume, 0.0);
+}
+
+TEST_F(FeaturePartCommonTest, testAlmostTouching)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[4]);
+
+    // Act
+    _common->execute();
+    Part::TopoShape ts = _common->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_FALSE(bb.IsValid());
+    EXPECT_DOUBLE_EQ(volume, 0.0);
+}
+
+TEST_F(FeaturePartCommonTest, testBarelyIntersecting)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[5]);  // NOLINT magic number
+
+    // Act
+    _common->execute();
+    Part::TopoShape ts = _common->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    double target = PartTestHelpers::minimalDistance * 3;  // 3 dimensions in a Volume
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    // Using FLOAT, not DOUBLE here so test library comparison is of reasonable precision 1e07
+    // rather than 1e15 See
+    // https://google.github.io/googletest/reference/assertions.html#floating-point
+    EXPECT_FLOAT_EQ(volume, target);  // Should be approximately 0.00029999999999996696
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 2.0 - PartTestHelpers::minimalDistance);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCommonTest, testMustExecute)
+{
+    // Assert initially we don't need to execute
+    EXPECT_FALSE(_common->mustExecute());
+    // Act to change one property
+    _common->Base.setValue(_boxes[0]);
+    // Assert we still can't execute
+    EXPECT_FALSE(_common->mustExecute());
+    // Act to complete the properties we need
+    _common->Tool.setValue(_boxes[1]);
+    // Assert that we now must execute
+    EXPECT_TRUE(_common->mustExecute());
+    // Act to execute
+    _doc->recompute();
+    // Assert we don't need to execute anymore
+    EXPECT_FALSE(_common->mustExecute());
+}
+
+TEST_F(FeaturePartCommonTest, testGetProviderName)
+{
+    // Act
+    _common->execute();
+    const char* name = _common->getViewProviderName();
+    // Assert
+    EXPECT_STREQ(name, "PartGui::ViewProviderBoolean");
+}
+
+TEST_F(FeaturePartCommonTest, testHistory)
+{
+    // Arrange
+    _common->Base.setValue(_boxes[0]);
+    _common->Tool.setValue(_boxes[1]);
+    // Manually create the histories classically generated by FreeCAD for comparison
+    using MapList = std::map<int, std::vector<int>>;
+    using List = std::vector<int>;
+    MapList compare1 = {{0, List {0}},
+                        {1, List {5}},  // NOLINT magic number
+                        {2, List()},
+                        {3, List {2}},
+                        {4, List {3}},
+                        {5, List {1}}};  // NOLINT magic number
+    MapList compare2 = {{0, List {0}},
+                        {1, List {5}},  // NOLINT magic number
+                        {2, List {4}},
+                        {3, List()},
+                        {4, List {3}},
+                        {5, List {1}}};  // NOLINT magic number
+
+    // Act and Assert no histories yet
+    std::vector<Part::ShapeHistory> hist = _common->History.getValues();
+    EXPECT_EQ(hist.size(), 0);
+
+    // Act to generate histories
+    _common->execute();
+    hist = _common->History.getValues();
+    // Assert
+    ASSERT_EQ(hist.size(), 2);
+    EXPECT_EQ(hist[0].shapeMap, compare1);
+    EXPECT_EQ(hist[1].shapeMap, compare2);
+
+    // Act to reverse the histories
+    _common->Base.setValue(_boxes[1]);
+    _common->Tool.setValue(_boxes[0]);
+    _common->execute();
+    hist = _common->History.getValues();
+    // Assert
+    ASSERT_EQ(hist.size(), 2);
+    EXPECT_EQ(hist[0].shapeMap, compare2);
+    EXPECT_EQ(hist[1].shapeMap, compare1);
+}
diff --git a/tests/src/Mod/Part/App/FeaturePartCut.cpp b/tests/src/Mod/Part/App/FeaturePartCut.cpp
new file mode 100644
index 0000000000..b5148d68ce
--- /dev/null
+++ b/tests/src/Mod/Part/App/FeaturePartCut.cpp
@@ -0,0 +1,176 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "gtest/gtest.h"
+
+#include "Mod/Part/App/FeaturePartCut.h"
+#include <src/App/InitApplication.h>
+
+#include "PartTestHelpers.h"
+
+class FeaturePartCutTest: public ::testing::Test, public PartTestHelpers::PartTestHelperClass
+{
+protected:
+    static void SetUpTestSuite()
+    {
+        tests::initApplication();
+    }
+
+    void SetUp() override
+    {
+        createTestDoc();
+        _cut = dynamic_cast<Part::Cut*>(_doc->addObject("Part::Cut"));
+    }
+
+    void TearDown() override
+    {}
+
+    Part::Cut* _cut = nullptr;  // NOLINT Can't be private in a test framework
+};
+
+TEST_F(FeaturePartCutTest, testIntersecting)
+{
+    // Arrange
+    _cut->Base.setValue(_boxes[0]);
+    _cut->Tool.setValue(_boxes[1]);
+
+    // Act
+    _cut->execute();
+    Part::TopoShape ts = _cut->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 3.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCutTest, testNonIntersecting)
+{
+    // Arrange
+    _cut->Base.setValue(_boxes[0]);
+    _cut->Tool.setValue(_boxes[2]);
+
+    // Act
+    _cut->execute();
+    Part::TopoShape ts = _cut->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 6.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCutTest, testTouching)
+{
+    // Arrange
+    _cut->Base.setValue(_boxes[0]);
+    _cut->Tool.setValue(_boxes[3]);
+
+    // Act
+    _cut->execute();
+    Part::TopoShape ts = _cut->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 6.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCutTest, testAlmostTouching)
+{
+    // Arrange
+    _cut->Base.setValue(_boxes[0]);
+    _cut->Tool.setValue(_boxes[4]);
+
+    // Act
+    _cut->execute();
+    Part::TopoShape ts = _cut->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 6.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCutTest, testBarelyIntersecting)
+{
+    // Arrange
+    _cut->Base.setValue(_boxes[0]);
+    _cut->Tool.setValue(_boxes[5]);  // NOLINT magic number
+
+    // Act
+    _cut->execute();
+    Part::TopoShape ts = _cut->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    double target = 6 - PartTestHelpers::minimalDistance * 3;  // NOLINT 3 dimensions in a Volume
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    // Using FLOAT, not DOUBLE here so test library comparison is of reasonable precision 1e07
+    // rather than 1e15 See
+    // https://google.github.io/googletest/reference/assertions.html#floating-point
+    EXPECT_FLOAT_EQ(volume, target);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 2.0 - PartTestHelpers::minimalDistance);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartCutTest, testMustExecute)
+{
+    // Assert initially we don't need to execute
+    EXPECT_FALSE(_cut->mustExecute());
+    // Act to change one property
+    _cut->Base.setValue(_boxes[0]);
+    // Assert we still can't execute
+    EXPECT_FALSE(_cut->mustExecute());
+    // Act to complete the properties we need
+    _cut->Tool.setValue(_boxes[1]);
+    // Assert that we now must execute
+    EXPECT_TRUE(_cut->mustExecute());
+    // Act to execute
+    _doc->recompute();
+    // Assert we don't need to execute anymore
+    EXPECT_FALSE(_cut->mustExecute());
+}
+
+TEST_F(FeaturePartCutTest, testGetProviderName)
+{
+    // Act
+    _cut->execute();
+    const char* name = _cut->getViewProviderName();
+    // Assert
+    EXPECT_STREQ(name, "PartGui::ViewProviderBoolean");
+}
+
+// See FeaturePartCommon.cpp for a history test.  It would be exactly the same and redundant here.
diff --git a/tests/src/Mod/Part/App/FeaturePartFuse.cpp b/tests/src/Mod/Part/App/FeaturePartFuse.cpp
new file mode 100644
index 0000000000..9ea4b11392
--- /dev/null
+++ b/tests/src/Mod/Part/App/FeaturePartFuse.cpp
@@ -0,0 +1,199 @@
+// SPDX-License-Identifier: LGPL-2.1-or-later
+
+#include "gtest/gtest.h"
+
+#include "Mod/Part/App/FeaturePartFuse.h"
+#include <src/App/InitApplication.h>
+
+#include "PartTestHelpers.h"
+
+
+class FeaturePartFuseTest: public ::testing::Test, public PartTestHelpers::PartTestHelperClass
+{
+protected:
+    static void SetUpTestSuite()
+    {
+        tests::initApplication();
+    }
+
+    void SetUp() override
+    {
+        createTestDoc();
+        _fuse = dynamic_cast<Part::Fuse*>(_doc->addObject("Part::Fuse"));
+    }
+
+    void TearDown() override
+    {}
+
+    Part::Fuse* _fuse = nullptr;  // NOLINT Can't be private in a test framework
+};
+
+TEST_F(FeaturePartFuseTest, testIntersecting)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[1]);
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 9.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 3.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartFuseTest, testNonIntersecting)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[2]);
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 12.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 5.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartFuseTest, testTouching)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[3]);
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_DOUBLE_EQ(volume, 12.0);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 4.0);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartFuseTest, testAlmostTouching)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[4]);
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    EXPECT_FLOAT_EQ(volume, 12.0);  // Use FLOAT to limit precision to 1E07 rather than 1E15
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_FLOAT_EQ(bb.MaxY, 4.0);  // Use FLOAT to limit precision to 1E07 rather than 1E15
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartFuseTest, testBarelyIntersecting)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[5]);  // NOLINT magic number
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    double volume = PartTestHelpers::getVolume(ts.getShape());
+    double target = 12 - PartTestHelpers::minimalDistance * 3;  // NOLINT 3 dimensions in a Volume
+    Base::BoundBox3d bb = ts.getBoundBox();
+
+    // Assert
+    // Using FLOAT, not DOUBLE here so test library comparison is of reasonable precision 1e07
+    // rather than 1e15 See
+    // https://google.github.io/googletest/reference/assertions.html#floating-point
+    EXPECT_FLOAT_EQ(volume, target);
+    // double check using bounds:
+    EXPECT_DOUBLE_EQ(bb.MinX, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinY, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MinZ, 0.0);
+    EXPECT_DOUBLE_EQ(bb.MaxX, 1.0);
+    EXPECT_DOUBLE_EQ(bb.MaxY, 4.0 - PartTestHelpers::minimalDistance);
+    EXPECT_DOUBLE_EQ(bb.MaxZ, 3.0);
+}
+
+TEST_F(FeaturePartFuseTest, testMustExecute)
+{
+    // Assert initially we don't need to execute
+    EXPECT_FALSE(_fuse->mustExecute());
+    // Act to change one property
+    _fuse->Base.setValue(_boxes[0]);
+    // Assert we still can't execute
+    EXPECT_FALSE(_fuse->mustExecute());
+    // Act to complete the properties we need
+    _fuse->Tool.setValue(_boxes[1]);
+    // Assert that we now must execute
+    EXPECT_TRUE(_fuse->mustExecute());
+    // Act to execute
+    _doc->recompute();
+    // Assert we don't need to execute anymore
+    EXPECT_FALSE(_fuse->mustExecute());
+}
+
+TEST_F(FeaturePartFuseTest, testGetProviderName)
+{
+    // Act
+    _fuse->execute();
+    const char* name = _fuse->getViewProviderName();
+    // Assert
+    EXPECT_STREQ(name, "PartGui::ViewProviderBoolean");
+}
+
+TEST_F(FeaturePartFuseTest, testRefine)
+{
+    // Arrange
+    _fuse->Base.setValue(_boxes[0]);
+    _fuse->Tool.setValue(_boxes[1]);
+
+    // Act
+    _fuse->execute();
+    Part::TopoShape ts = _fuse->Shape.getValue();
+    std::vector<Part::TopoShape> subs =
+        ts.getSubTopoShapes(TopAbs_FACE);  // TopAbs_WIRE alternate approach
+    // Assert two boxes, plus redundant faces at the joint.
+    EXPECT_EQ(subs.size(), 14);
+    // Act
+    _fuse->Refine.setValue(true);
+    _fuse->execute();
+    ts = _fuse->Shape.getValue();
+    subs = ts.getSubTopoShapes(TopAbs_FACE);
+    // Assert we now just have one big box
+    EXPECT_EQ(subs.size(), 6);
+}
+
+// See FeaturePartCommon.cpp for a history test.  It would be exactly the same and redundant here.
diff --git a/tests/src/Mod/Part/App/PartTestHelpers.cpp b/tests/src/Mod/Part/App/PartTestHelpers.cpp
new file mode 100644
index 0000000000..cdcfa44e95
--- /dev/null
+++ b/tests/src/Mod/Part/App/PartTestHelpers.cpp
@@ -0,0 +1,38 @@
+
+#include "PartTestHelpers.h"
+
+namespace PartTestHelpers
+{
+
+double getVolume(const TopoDS_Shape shape)
+{
+    GProp_GProps prop;
+    BRepGProp::VolumeProperties(shape, prop);
+    return prop.Mass();
+}
+
+void PartTestHelperClass::createTestDoc()
+{
+    _docName = App::GetApplication().getUniqueDocumentName("test");
+    _doc = App::GetApplication().newDocument(_docName.c_str(), "testUser");
+    std::array<Base::Vector3d, 6> box_origins = {
+        // NOLINT magic number
+        Base::Vector3d(),                                        // First box at 0,0,0
+        Base::Vector3d(0, 1, 0),                                 // Overlap with first box
+        Base::Vector3d(0, 3, 0),                                 // Don't Overlap with first box
+        Base::Vector3d(0, 2, 0),                                 // Touch the first box
+        Base::Vector3d(0, 2 + Base::Precision::Confusion(), 0),  // Just Outside of touching
+        // For the Just Inside Of Touching case, go enough that we exceed precision rounding
+        Base::Vector3d(0, 2 - minimalDistance, 0)};
+
+    for (int i = 0; i < _boxes.size(); i++) {
+        auto box = _boxes[i] = static_cast<Part::Box*>(_doc->addObject("Part::Box"));
+        box->Length.setValue(1);
+        box->Width.setValue(2);
+        box->Height.setValue(3);
+        box->Placement.setValue(
+            Base::Placement(box_origins[i], Base::Rotation(), Base::Vector3d()));
+    }
+}
+
+}  // namespace PartTestHelpers
diff --git a/tests/src/Mod/Part/App/PartTestHelpers.h b/tests/src/Mod/Part/App/PartTestHelpers.h
new file mode 100644
index 0000000000..cc2be6e1c6
--- /dev/null
+++ b/tests/src/Mod/Part/App/PartTestHelpers.h
@@ -0,0 +1,25 @@
+#include <App/Application.h>
+#include <App/Document.h>
+#include <Base/Precision.h>
+#include "Mod/Part/App/FeaturePartBox.h"
+#include "Mod/Part/App/FeaturePartFuse.h"
+#include "Mod/Part/App/FeatureFillet.h"
+#include <BRepGProp.hxx>
+
+namespace PartTestHelpers
+{
+
+double getVolume(TopoDS_Shape shape);
+
+class PartTestHelperClass
+{
+public:
+    App::Document* _doc;
+    std::string _docName;
+    std::array<Part::Box*, 6> _boxes;
+    void createTestDoc();
+};
+
+const double minimalDistance = Base::Precision::Confusion() * 1000;
+
+}  // namespace PartTestHelpers