diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..8ce093c
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,20 @@
+from pathlib import Path
+
+import pytest
+
+
+@pytest.fixture
+def test_data_folder() -> Path:
+    return Path(__file__).parent / "data"
+
+
+@pytest.fixture
+def test_data_clean(test_data_folder: Path) -> str:
+    file_path = test_data_folder / "Example_Clean.xml"
+    return file_path.as_posix()
+
+
+@pytest.fixture
+def test_data_mesh2dm(test_data_folder: Path) -> str:
+    file_path = test_data_folder / "mesh.2dm"
+    return file_path.as_posix()
diff --git a/tests/test_2dm_reader.py b/tests/test_2dm_reader.py
new file mode 100644
index 0000000..beffb6f
--- /dev/null
+++ b/tests/test_2dm_reader.py
@@ -0,0 +1,18 @@
+from landxmlconvertor.classes.mesh2dm_reader import Mesh2DMReader
+from landxmlconvertor.classes.mesh_elements import MeshFace, MeshVertex
+
+
+def test_read(test_data_mesh2dm):
+    mesh_2d = Mesh2DMReader(test_data_mesh2dm)
+
+    assert isinstance(mesh_2d, Mesh2DMReader)
+    assert all([isinstance(x, MeshVertex) for x in mesh_2d.points])
+    assert all([isinstance(x, MeshFace) for x in mesh_2d.faces])
+
+    assert all([isinstance(x.id, int) for x in mesh_2d.points])
+    assert all([isinstance(x.x, float) for x in mesh_2d.points])
+    assert all([isinstance(x.y, float) for x in mesh_2d.points])
+    assert all([isinstance(x.z, float) for x in mesh_2d.points])
+
+    assert all([isinstance(x.id, int) for x in mesh_2d.faces])
+    assert all([all([isinstance(y, int) for y in x.points_ids]) for x in mesh_2d.faces])
diff --git a/tests/test_conversions.py b/tests/test_conversions.py
new file mode 100644
index 0000000..fffb990
--- /dev/null
+++ b/tests/test_conversions.py
@@ -0,0 +1,55 @@
+import tempfile
+from pathlib import Path
+
+import pytest
+from qgis.core import QgsCoordinateReferenceSystem, QgsMeshLayer
+
+from landxmlconvertor.classes.landxml_reader import LandXMLReader
+from landxmlconvertor.classes.landxml_writer import LandXMLWriter
+from landxmlconvertor.classes.mesh2dm_writer import Mesh2DMWriter
+
+
+@pytest.mark.parametrize(
+    "filename",
+    [
+        ("Example_Clean.xml"),
+        ("Example_Clean_without_schema.xml"),
+    ],
+)
+def test_landxml_to_2dm(test_data_folder, filename):
+    current_filename = test_data_folder / filename
+
+    land_xml = LandXMLReader(current_filename.as_posix())
+
+    mesh_2dm_writer = Mesh2DMWriter(land_xml.all_points, land_xml.all_faces)
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        tmp_2dm_file = Path(tmpdir) / "file.2dm"
+
+        mesh_2dm_writer.write(tmp_2dm_file.as_posix())
+
+        mesh = QgsMeshLayer(tmp_2dm_file.as_posix(), "layer", "mdal")
+
+        assert mesh.dataProvider().vertexCount() == 264
+        assert mesh.dataProvider().faceCount() == 362
+
+
+def test_2dm_to_landxml(test_data_folder):
+    current_filename = test_data_folder / "mesh.2dm"
+
+    mesh_2dm = QgsMeshLayer(current_filename.as_posix(), "layer", "mdal")
+
+    with tempfile.TemporaryDirectory() as tmpdir:
+        tmp_landxml_file = Path(tmpdir) / "file.xml"
+
+        landxml_writer = LandXMLWriter()
+        landxml_writer.add_surface(mesh_2dm)
+        landxml_writer.write(tmp_landxml_file.as_posix())
+
+        landxml_reader = LandXMLReader(tmp_landxml_file.as_posix())
+
+        assert landxml_reader.namespace_prefix == "LandXML-1.2:"
+        assert landxml_reader.crs() == QgsCoordinateReferenceSystem()
+        assert landxml_reader.surface_count == 1
+        assert len(landxml_reader.all_faces) == 45
+        assert len(landxml_reader.all_points) == 29
diff --git a/tests/test_landxml_reader.py b/tests/test_landxml_reader.py
new file mode 100644
index 0000000..b321a39
--- /dev/null
+++ b/tests/test_landxml_reader.py
@@ -0,0 +1,105 @@
+import xml.etree.ElementTree as ET
+
+import pytest
+from qgis.core import QgsCoordinateReferenceSystem
+
+from landxmlconvertor.classes.landxml_elements import LandXMLSurface
+from landxmlconvertor.classes.landxml_reader import LandXMLReader
+from landxmlconvertor.classes.mesh_elements import MeshFace, MeshVertex
+
+
+@pytest.mark.parametrize(
+    "filename",
+    [
+        ("Example_Clean.xml"),
+        ("Example_Clean_without_schema.xml"),
+    ],
+)
+def test_clean_data(test_data_folder, filename):
+    current_filename = test_data_folder / filename
+
+    land_xml = LandXMLReader(current_filename.as_posix())
+
+    assert land_xml.path == current_filename.as_posix()
+    assert isinstance(land_xml.xml_tree, ET.ElementTree)
+
+    assert isinstance(land_xml.xml_root, ET.Element)
+    assert "LandXML" in land_xml.xml_root.tag
+
+    assert land_xml.crs() == QgsCoordinateReferenceSystem()
+
+    assert land_xml.surface_count == 3
+
+    assert all([isinstance(x, LandXMLSurface) for x in land_xml.surfaces])
+
+    assert len(land_xml.get_surface_points(0)) == 29
+    assert len(land_xml.get_surface_faces(0)) == 45
+
+    assert len(land_xml.get_surface_points(1)) == 92
+    assert len(land_xml.get_surface_faces(1)) == 138
+
+    assert len(land_xml.get_surface_points(2)) == 143
+    assert len(land_xml.get_surface_faces(2)) == 179
+
+    assert all([isinstance(x, MeshVertex) for x in land_xml.get_surface_points(0)])
+    assert all([isinstance(x, MeshFace) for x in land_xml.get_surface_faces(0)])
+
+    assert len(land_xml.all_points) == 29 + 92 + 143
+    assert len(land_xml.all_faces) == 45 + 138 + 179
+
+
+def test_non_existing_file():
+    with pytest.raises(FileNotFoundError, match="No such file"):
+        LandXMLReader("file_that_does_not_exist.xml")
+
+
+def test_non_LandXML_file(test_data_folder):
+    filename = test_data_folder / "just_xml.xml"
+    with pytest.raises(ValueError, match="Not a valid LandXML file"):
+        LandXMLReader(filename.as_posix())
+
+
+def test_LandXML_without_surface_1(test_data_folder):
+    filename = test_data_folder / "land_xml_no_surface.xml"
+
+    land_xml = LandXMLReader(filename.as_posix())
+
+    assert land_xml.surface_count == 0
+
+
+def test_LandXML_without_surface_2(test_data_folder):
+    filename = test_data_folder / "land_xml_empty_surface.xml"
+
+    land_xml = LandXMLReader(filename.as_posix())
+
+    assert land_xml.surface_count == 1
+    assert land_xml.surfaces[0].empty()
+
+
+def test_LandXML_unsupported_schema(test_data_folder):
+    filename = test_data_folder / "land_xml_with_unsupported_schema.xml"
+
+    with pytest.raises(ValueError, match="Unsupported namespace: "):
+        LandXMLReader(filename.as_posix())
+
+
+def test_data_1(test_data_folder):
+    filename = test_data_folder / "Total topp.xml"
+
+    landxml_reader = LandXMLReader(filename.as_posix())
+
+    assert landxml_reader.crs() == QgsCoordinateReferenceSystem()
+    assert landxml_reader.surface_count == 1
+    assert len(landxml_reader.all_faces) == 36093
+    assert len(landxml_reader.all_points) == 22273
+
+
+def test_data_2(test_data_folder):
+    filename = test_data_folder / "3D_modell_underlag_skyfall_20230915.xml"
+
+    landxml_reader = LandXMLReader(filename.as_posix())
+
+    assert landxml_reader.crs() == QgsCoordinateReferenceSystem("EPSG:3007")
+    assert landxml_reader.surface_count == 1
+    assert len(landxml_reader.all_faces) == 6448
+    assert len(landxml_reader.all_points) == 3330