Add tests for reading images

Author: seisman

pygmt/io/gmtread.py

@@ -75,6 +75,11 @@ def gmtread(
     >>> dataarray = gmtread("@earth_relief_01d", kind="grid")
     >>> type(dataarray)
     <class 'xarray.core.dataarray.DataArray'>
+
+    Read an image into an :class:`xarray.DataArray` object:
+    >>> image = gmtread("@earth_day_01d", kind="image")
+    >>> type(image)
+    <class 'xarray.core.dataarray.DataArray'>
     """
     if kind not in {"dataset", "grid", "image"}:
         msg = f"Invalid kind '{kind}': must be one of 'dataset', 'grid', or 'image'."

pygmt/tests/test_io_gmtread.py

@@ -6,10 +6,12 @@
 
 import numpy as np
 import pytest
+import rioxarray
 import xarray as xr
 from pygmt import gmtread, which
 
 _HAS_NETCDF4 = bool(importlib.util.find_spec("netCDF4"))
+_HAS_RIORASTERIO = bool(importlib.util.find_spec("rioxarray"))
 
 
 @pytest.mark.skipif(not _HAS_NETCDF4, reason="netCDF4 is not installed.")
@@ -24,6 +26,19 @@ def test_io_gmtread_grid():
     assert np.allclose(grid, expected_grid)
 
 
+@pytest.mark.skipif(not _HAS_RIORASTERIO, reason="rioxarray is not installed.")
+def test_io_gmtread_image():
+    """
+    Test that reading an image returns an xr.DataArray.
+    """
+    image = gmtread("@earth_day_01d", kind="image")
+    assert isinstance(image, xr.DataArray)
+    with rioxarray.open_rasterio(
+        which("@earth_day_01d", download="a")
+    ) as expected_image:
+        assert np.allclose(image, expected_image)
+
+
 def test_io_gmtread_invalid_kind():
     """
     Test that an invalid kind raises a ValueError.