Add some tests for interpolation methods

tests/test_interpolation.py

@@ -5,6 +5,31 @@
 import parcels._interpolation as interpolation
 
 
+
+
+@pytest.fixture
+def tmp_interpolator_registry():
+    """Resets the interpolator registry after the test. Vital when testing manipulating the registry."""
+    old_2d = interpolation.interpolator_registry_2d.copy()
+    old_3d = interpolation.interpolator_registry_3d.copy()
+    yield
+    interpolation.interpolator_registry_2d = old_2d
+    interpolation.interpolator_registry_3d = old_3d
+
+
+def test_interpolation_registry(tmp_interpolator_registry):
+    @interpolation.register_3d_interpolator("test")
+    @interpolation.register_2d_interpolator("test")
+    def some_function():
+        return "test"
+
+    assert "test" in interpolation.interpolator_registry_2d
+    assert "test" in interpolation.interpolator_registry_3d
+
+    f = interpolation.interpolator_registry_2d["test"]
+    g = interpolation.interpolator_registry_3d["test"]
+    assert f() == g() == "test"
+
 def create_interpolation_data():
     """Reference data used for testing interpolation.
 
@@ -35,25 +60,38 @@ def data_3d():
     return create_interpolation_data().values
 
 
-@pytest.fixture
-def tmp_interpolator_registry():
-    """Resets the interpolator registry after the test. Vital when testing manipulating the registry."""
-    old_2d = interpolation.interpolator_registry_2d.copy()
-    old_3d = interpolation.interpolator_registry_3d.copy()
-    yield
-    interpolation.interpolator_registry_2d = old_2d
-    interpolation.interpolator_registry_3d = old_3d
-
 
-def test_interpolation_registry(tmp_interpolator_registry):
-    @interpolation.register_3d_interpolator("test")
-    @interpolation.register_2d_interpolator("test")
-    def some_function():
-        return "test"
+class TestInterpolationMethods:
+    ti = 0
+    zi, yi, xi = 1, 1, 1
 
-    assert "test" in interpolation.interpolator_registry_2d
-    assert "test" in interpolation.interpolator_registry_3d
+    @pytest.mark.parametrize(
+        "func, eta, xi, expected",
+        [
+            pytest.param(interpolation._nearest_2d, 0.49, 0.49, 3.0, id="nearest_2d-1"),
+            pytest.param(interpolation._nearest_2d, 0.49, 0.51, 4.0, id="nearest_2d-2"),
+            pytest.param(interpolation._nearest_2d, 0.51, 0.49, 5.0, id="nearest_2d-3"),
+            pytest.param(interpolation._nearest_2d, 0.51, 0.51, 6.0, id="nearest_2d-4"),
+            pytest.param(interpolation._tracer_2d, None, None, 6.0, id="tracer_2d"),
+            # pytest.param(interpolation._linear_2d, ...),
+            # pytest.param(interpolation._linear_invdist_land_tracer_2d, ...),
+            
+        ],
+    )
+    def test_2d(self, data_2d, func, eta, xi, expected):
+        ctx = interpolation.InterpolationContext2D(data_2d, eta, xi, self.ti, self.yi, self.xi)
+        assert func(ctx) == expected
 
-    f = interpolation.interpolator_registry_2d["test"]
-    g = interpolation.interpolator_registry_3d["test"]
-    assert f() == g() == "test"
+    @pytest.mark.parametrize(
+        "func, eta, xi, expected",
+        [
+            # pytest.param(interpolation._nearest_3d, ...),
+            # pytest.param(interpolation._cgrid_velocity_3d, ...),
+            # pytest.param(interpolation._linear_invdist_land_tracer_3d, ...),
+            # pytest.param(interpolation._linear_3d, ...),
+            # pytest.param(interpolation._tracer_3d, ...),
+        ],
+    )
+    def test_3d(self, data_3d, func, zeta, eta, xi, expected):
+        ctx = interpolation.InterpolationContext3D(data_2d, zeta, eta, xi, self.ti, self.zi, self.yi, self.xi)
+        assert func(ctx) == expected