Add Unet++ test

Author: qubvel

tests/models/test_unetplusplus.py

@@ -1,6 +1,35 @@
+import segmentation_models_pytorch as smp
+
 from tests.models import base
 
 
 class TestUnetPlusPlusModel(base.BaseModelTester):
     test_model_type = "unetplusplus"
     files_for_diff = [r"decoders/unetplusplus/", r"base/"]
+
+    def test_interpolation(self):
+        # test bilinear
+        model_1 = smp.create_model(
+            self.test_model_type,
+            self.test_encoder_name,
+            decoder_interpolation="bilinear",
+        )
+        is_tested = False
+        for module in model_1.decoder.modules():
+            if module.__class__.__name__ == "DecoderBlock":
+                assert module.interpolation_mode == "bilinear"
+                is_tested = True
+        assert is_tested
+
+        # test bicubic
+        model_2 = smp.create_model(
+            self.test_model_type,
+            self.test_encoder_name,
+            decoder_interpolation="bicubic",
+        )
+        is_tested = False
+        for module in model_2.decoder.modules():
+            if module.__class__.__name__ == "DecoderBlock":
+                assert module.interpolation_mode == "bicubic"
+                is_tested = True
+        assert is_tested