Use xarray.testing rather than pygmt.grdinfo in xyz2grd tests (#1682)

Update xyz2grd tests to use xarray.testing and new syntax for loading data

Co-authored-by: Dongdong Tian <[email protected]>
Co-authored-by: Meghan Jones <[email protected]>

pygmt/tests/test_xyz2grd.py

@@ -6,8 +6,8 @@
 import numpy as np
 import pytest
 import xarray as xr
-from pygmt import grdinfo, xyz2grd
-from pygmt.datasets import load_sample_bathymetry
+from pygmt import load_dataarray, xyz2grd
+from pygmt.datasets import load_sample_data
 from pygmt.helpers import GMTTempFile
 
 
@@ -16,54 +16,52 @@ def fixture_ship_data():
     """
     Load the data from the sample bathymetry dataset.
     """
-    return load_sample_bathymetry()
+    return load_sample_data(name="bathymetry")
 
 
-def test_xyz2grd_input_file():
+@pytest.fixture(scope="module", name="expected_grid")
+def fixture_grid_result():
     """
-    Run xyz2grd by passing in a filename.
+    Load the expected xyz2grd grid result.
     """
-    output = xyz2grd(data="@tut_ship.xyz", spacing=5, region=[245, 255, 20, 30])
-    assert isinstance(output, xr.DataArray)
-    assert output.gmt.registration == 0  # Gridline registration
-    assert output.gmt.gtype == 0  # Cartesian type
-    return output
-
-
-def test_xyz2grd_input_array(ship_data):
-    """
-    Run xyz2grd by passing in a numpy array.
-    """
-    output = xyz2grd(data=np.array(ship_data), spacing=5, region=[245, 255, 20, 30])
-    assert isinstance(output, xr.DataArray)
-    assert output.gmt.registration == 0  # Gridline registration
-    assert output.gmt.gtype == 0  # Cartesian type
-    return output
+    return xr.DataArray(
+        data=[
+            [-3651.0608, -3015.214, -2320.1033],
+            [-2546.2512, -1977.8754, -963.23303],
+            [-352.3795, -1025.4508, np.nan],
+        ],
+        coords=dict(
+            x=[245.0, 250.0, 255.0],
+            y=[20.0, 25.0, 30.0],
+        ),
+        dims=["y", "x"],
+    )
 
 
-def test_xyz2grd_input_df(ship_data):
+@pytest.mark.parametrize("array_func", [np.array, xr.Dataset])
+def test_xyz2grd_input_array(array_func, ship_data, expected_grid):
     """
-    Run xyz2grd by passing in a data frame.
+    Run xyz2grd by passing in an xarray datset or numpy array.
     """
-    output = xyz2grd(data=ship_data, spacing=5, region=[245, 255, 20, 30])
+    output = xyz2grd(data=array_func(ship_data), spacing=5, region=[245, 255, 20, 30])
     assert isinstance(output, xr.DataArray)
     assert output.gmt.registration == 0  # Gridline registration
     assert output.gmt.gtype == 0  # Cartesian type
-    return output
+    xr.testing.assert_allclose(a=output, b=expected_grid)
 
 
-def test_xyz2grd_input_array_file_out(ship_data):
+def test_xyz2grd_input_array_file_out(ship_data, expected_grid):
     """
     Run xyz2grd by passing in a numpy array and set an outgrid file.
     """
     with GMTTempFile(suffix=".nc") as tmpfile:
         result = xyz2grd(
-            data=np.array(ship_data),
+            data=ship_data,
             spacing=5,
             region=[245, 255, 20, 30],
             outgrid=tmpfile.name,
         )
         assert result is None  # return value is None
         assert os.path.exists(path=tmpfile.name)
-        result = grdinfo(tmpfile.name, per_column=True).strip()
-        assert result == "245 255 20 30 -3651.06079102 -352.379486084 5 5 3 3 0 0"
+        temp_grid = load_dataarray(tmpfile.name)
+        xr.testing.assert_allclose(a=temp_grid, b=expected_grid)