Add load_static_earth_relief function for internal testing (#1727)

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

Author: willschlitzer

pygmt/helpers/testing.py

@@ -7,6 +7,7 @@
 
 from matplotlib.testing.compare import compare_images
 from pygmt.exceptions import GMTImageComparisonFailure
+from pygmt.io import load_dataarray
 from pygmt.src import which
 
 
@@ -178,10 +179,24 @@ def download_test_data():
         "@ridge.txt",
         "@mars370d.txt",
         "@srtm_tiles.nc",  # needed for 03s and 01s relief data
+        "@static_earth_relief.nc",
         "@test.dat.nc",
         "@tut_bathy.nc",
         "@tut_quakes.ngdc",
         "@tut_ship.xyz",
         "@usgs_quakes_22.txt",
     ]
     which(fname=datasets, download="a")
+
+
+def load_static_earth_relief():
+    """
+    Load the static_earth_relief file for internal testing.
+
+    Returns
+    -------
+    data : xarray.DataArray
+        A grid of Earth relief for internal tests.
+    """
+    fname = which("@static_earth_relief.nc", download="c")
+    return load_dataarray(fname)

pygmt/tests/test_helpers.py

@@ -5,6 +5,7 @@
 
 import numpy as np
 import pytest
+import xarray as xr
 from pygmt.exceptions import GMTInvalidInput
 from pygmt.helpers import (
     GMTTempFile,
@@ -13,6 +14,20 @@
     kwargs_to_strings,
     unique_name,
 )
+from pygmt.helpers.testing import load_static_earth_relief
+
+
+def test_load_static_earth_relief():
+    """
+    Check that @static_earth_relief.nc loads without errors.
+    """
+    data = load_static_earth_relief()
+    assert data.dims == ("lat", "lon")
+    assert data.shape == (14, 8)
+    assert data.min() == 190
+    assert data.max() == 981
+    assert data.median() == 467
+    assert isinstance(data, xr.DataArray)
 
 
 @pytest.mark.parametrize(