Added crs converter function and test

geest/core/crs_converter.py

@@ -0,0 +1,40 @@
+from qgis.core import QgsCoordinateTransform, QgsCoordinateReferenceSystem, QgsProcessingFeedback, QgsVectorLayer
+from qgis import processing
+
+class CRSConverter:
+    def __init__(self, layer):
+        """
+        Initialize the CRSConverter class with a given layer.
+        :param layer: The input layer for CRS conversion (QgsVectorLayer or QgsRasterLayer)
+        """
+        self.layer = layer
+
+    def convert_to_crs(self, target_crs_epsg):
+        """
+        Converts the layer's CRS to the target CRS based on the EPSG code.
+        :param target_crs_epsg: EPSG code of the target CRS
+        """
+        # Get the current CRS of the layer
+        current_crs = self.layer.crs()
+
+        # Create the target CRS using the EPSG code
+        target_crs = QgsCoordinateReferenceSystem(f"EPSG:{target_crs_epsg}")
+
+        # Check if the current CRS is the same as the target CRS
+        if current_crs != target_crs:
+            print(f"Converting layer from {current_crs.authid()} to {target_crs.authid()}")
+
+            layer = processing.run(
+                "native:reprojectlayer",
+                {
+                    "INPUT": self.layer,
+                    "TARGET_CRS": target_crs,
+                    "OUTPUT": "memory:",
+                },
+                feedback=QgsProcessingFeedback(),
+            )["OUTPUT"]
+            print(f"Layer successfully converted to {target_crs.authid()}")
+            return layer
+        else:
+            print(f"Layer is already in the target CRS: {target_crs.authid()}")
+            return self.layer

test/test_crs_converter.py

@@ -0,0 +1,61 @@
+import unittest
+import os
+from qgis.core import QgsVectorLayer, QgsCoordinateReferenceSystem
+from geest.core.crs_converter import CRSConverter
+
+
+class TestCRSConverter(unittest.TestCase):
+
+    def setUp(self):
+        """
+        Setup method that runs before each test. It prepares the environment.
+        """
+        # Define paths for test data
+        self.working_dir = os.path.dirname(__file__)
+        self.test_data_dir = os.path.join(self.working_dir, "test_data")
+
+        # Load a test layer from the test data directory
+        self.layer = QgsVectorLayer(
+            os.path.join(self.test_data_dir, "admin/Admin0.shp"), "test_layer", "ogr"
+        )
+        self.assertTrue(self.layer.isValid(), "Layer failed to load!")
+
+    def test_crs_conversion(self):
+        """
+        Test CRS conversion to a different CRS.
+        """
+        # Create an instance of CRSConverter with the test layer
+        converter = CRSConverter(self.layer)
+
+        # Convert the layer to a different CRS (EPSG:3857 "Web Mercator")
+        target_epsg = 3857
+        reprojected_layer = converter.convert_to_crs(target_epsg)
+
+        # Get the new CRS of the reprojected layer
+        new_crs = reprojected_layer.crs()
+
+        # Check if the CRS was converted correctly
+        expected_crs = QgsCoordinateReferenceSystem(target_epsg)
+        self.assertEqual(
+            new_crs.authid(), expected_crs.authid(), "CRS conversion failed!"
+        )
+
+    def test_no_conversion_needed(self):
+        """
+        Test if no conversion is performed when the layer is already in the target CRS.
+        """
+        # Create an instance of CRSConverter with the test layer
+        converter = CRSConverter(self.layer)
+
+        # Convert to the same CRS (EPSG:4326)
+        target_epsg = 4326
+        reprojected_layer = converter.convert_to_crs(target_epsg)
+
+        # Check that the CRS remains the same
+        self.assertEqual(
+            reprojected_layer.crs().authid(), "EPSG:4326", "Layer CRS should remain unchanged!"
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

test/test_polygons_per_grid_cell.py

@@ -29,9 +29,7 @@ def test_raster_polygon_grid_score(self):
         )
         self.country_boundary = os.path.join(self.test_data_dir, "admin/Admin0.shp")
 
-        self.assertTrue(
-            self.polygon_layer.isValid(), "The polygon layer is not valid."
-        )
+        self.assertTrue(self.polygon_layer.isValid(), "The polygon layer is not valid.")
 
         # Define output path for the generated raster
         self.output_path = os.path.join(