From fa012a541cae2404df0e9eb20931be85a0480898 Mon Sep 17 00:00:00 2001
From: James Douglass <jdouglass@stanford.edu>
Date: Tue, 7 Jan 2025 14:39:15 -0800
Subject: [PATCH] Adding error checking for base, target paths.

RE:#421
---
 HISTORY.rst                          |  3 +++
 src/pygeoprocessing/geoprocessing.py |  8 +++++++-
 tests/test_geoprocessing.py          | 26 +++++++++++++++++++++++++-
 3 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/HISTORY.rst b/HISTORY.rst
index 194627fd..eda9e81c 100644
--- a/HISTORY.rst
+++ b/HISTORY.rst
@@ -7,6 +7,9 @@ Release History
   https://github.com/natcap/pygeoprocessing/issues/415
 * Added validation to ``reclassify_raster`` to raise a ``TypeError`` with a
   descriptive message if ``value_map`` contains non-numeric keys.
+* If either ``base_raster_path`` or ``target_raster_path`` are not strings, a
+  ``ValueError`` is now raised with a more helpful error message.
+  https://github.com/natcap/pygeoprocessing/issues/421
 
 2.4.6 (2024-10-15)
 ------------------
diff --git a/src/pygeoprocessing/geoprocessing.py b/src/pygeoprocessing/geoprocessing.py
index 9bfac019..44cadbcf 100644
--- a/src/pygeoprocessing/geoprocessing.py
+++ b/src/pygeoprocessing/geoprocessing.py
@@ -2507,8 +2507,14 @@ def warp_raster(
             if ``mask_options`` is not None but the
             ``mask_vector_path`` is undefined or doesn't point to a valid
             file.
-
+        ValueError
+            if either ``base_raster_path`` or ``target_raster_path`` are
+            not strings.
     """
+    for path_key in ['base_raster_path', 'target_raster_path']:
+        if not isinstance(locals()[path_key], str):
+            raise ValueError('%s must be a string', path_key)
+
     _assert_is_valid_pixel_size(target_pixel_size)
 
     base_raster_info = get_raster_info(base_raster_path)
diff --git a/tests/test_geoprocessing.py b/tests/test_geoprocessing.py
index 1dd30d61..c44dee3b 100644
--- a/tests/test_geoprocessing.py
+++ b/tests/test_geoprocessing.py
@@ -196,7 +196,7 @@ def test_reclassify_raster_nonnumeric_key(self):
         target_path = os.path.join(self.workspace_dir, 'target.tif')
         _array_to_raster(
             pixel_matrix, target_nodata, raster_path)
-        
+
         value_map = {1: 2, None: 3, "s": 4, numpy.nan: 5, numpy.float32(99): 6}
         with self.assertRaises(TypeError) as e:
             pygeoprocessing.reclassify_raster(
@@ -1754,6 +1754,30 @@ def test_warp_raster(self):
                 pygeoprocessing.raster_to_numpy_array(
                     target_raster_path)).all())
 
+    def test_warp_raster_invalid_paths(self):
+        """PGP.geoprocessing: error on invalid raster paths."""
+        pixel_a_matrix = numpy.ones((5, 5), numpy.int16)
+        target_nodata = -1
+        base_a_path = os.path.join(self.workspace_dir, 'base_a.tif')
+        _array_to_raster(
+            pixel_a_matrix, target_nodata, base_a_path)
+
+        target_raster_path = os.path.join(self.workspace_dir, 'target_a.tif')
+        base_a_raster_info = pygeoprocessing.get_raster_info(base_a_path)
+
+        for invalid_source_path in [(base_a_path,), (base_a_path, 1)]:
+            with self.assertRaises(ValueError):
+                pygeoprocessing.warp_raster(
+                    invalid_source_path, base_a_raster_info['pixel_size'],
+                    target_raster_path, 'near', n_threads=1)
+
+        for invalid_target_path in [(target_raster_path,),
+                                    (target_raster_path, 1)]:
+            with self.assertRaises(ValueError):
+                pygeoprocessing.warp_raster(
+                    base_a_path, base_a_raster_info['pixel_size'],
+                    invalid_target_path, 'near', n_threads=1)
+
     def test_warp_raster_overview_level(self):
         """PGP.geoprocessing: warp raster overview test."""
         # This array is big enough that build_overviews will render several