Implement download_url tests for SAMPLE_TIFF

Add tests for downloading a sample TIFF file with hash validation.

Signed-off-by: Enoch Mok <65853622+e-mny@users.noreply.github.com>

Author: e-mny

tests/test_utils.py

@@ -184,6 +184,32 @@ def skip_if_downloading_fails():
         raise rt_e
 
 
+SAMPLE_TIFF = (
+    https://huggingface.co/datasets/MONAI/testing_data/resolve/main/CMU-1.tiff
+)
+
+SAMPLE_TIFF_HASH = "73a7e89bc15576587c3d68e55d9bf92f09690280166240b48ff4b48230b13bcd"
+SAMPLE_TIFF_HASH_TYPE = "sha256"
+
+def test_download_url():
+    with tempfile.TemporaryDirectory() as tempdir:
+        # successful download with correct hash
+        download_url(
+            url=SAMPLE_TIFF,
+            filepath=os.path.join(tempdir, "model.tiff"),
+            hash_val=SAMPLE_TIFF_HASH,
+            hash_type=SAMPLE_TIFF_HASH_TYPE,
+        )
+        
+        # fails with wrong hash
+        with self.assertRaises(RuntimeError):
+            download_url(
+                url=SAMPLE_TIFF,
+                filepath=os.path.join(tempdir, "model_bad.tiff"),
+                hash_val="wrong_hash",
+                hash_type=SAMPLE_TIFF_HASH_TYPE,
+            )
+
 def test_pretrained_networks(network, input_param, device):
     with skip_if_downloading_fails():
         return network(**input_param).to(device)