From dedf242af0c9d64323f352f92ea0cef5442d1d21 Mon Sep 17 00:00:00 2001
From: Wei Ji <23487320+weiji14@users.noreply.github.com>
Date: Sun, 12 Sep 2021 22:31:25 +1200
Subject: [PATCH] Add tests for load_dataarray to increase code coverage

---
 pygmt/tests/test_io.py | 34 ++++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 pygmt/tests/test_io.py

diff --git a/pygmt/tests/test_io.py b/pygmt/tests/test_io.py
new file mode 100644
index 00000000000..82975442613
--- /dev/null
+++ b/pygmt/tests/test_io.py
@@ -0,0 +1,34 @@
+"""
+Tests for input/output (I/O) utilities.
+"""
+import numpy as np
+import pytest
+import xarray as xr
+from pygmt.helpers import GMTTempFile
+from pygmt.io import load_dataarray
+
+
+def test_io_load_dataarray():
+    """
+    Check that load_dataarray works to read a NetCDF grid with
+    GMTDataArrayAccessor information loaded.
+    """
+    with GMTTempFile(suffix=".nc") as tmpfile:
+        grid = xr.DataArray(
+            data=np.random.rand(2, 2), coords=[[0.1, 0.2], [0.3, 0.4]], dims=("x", "y")
+        )
+        grid.to_netcdf(tmpfile.name)
+        ds = load_dataarray(tmpfile.name)
+        assert ds.gmt.gtype == 0  # Cartesian grid
+        assert ds.gmt.registration == 1  # Pixel registration
+        # this would fail if we used xr.open_dataarray instead of
+        # load_dataarray
+        ds.to_netcdf(tmpfile.name)
+
+
+def test_io_load_dataarray_cache():
+    """
+    Check that load_dataarray fails when the cache argument is used.
+    """
+    with pytest.raises(TypeError):
+        _ = load_dataarray("somefile.nc", cache=True)