[diffusion] fix: fix temporary resolution workaround (#20046)

python/sglang/multimodal_gen/test/unit/test_sampling_params.py

@@ -1,6 +1,10 @@
 import math
 import unittest
 
+from sglang.multimodal_gen.configs.sample.diffusers_generic import (
+    DiffusersGenericSamplingParams,
+)
+from sglang.multimodal_gen.configs.sample.flux import FluxSamplingParams
 from sglang.multimodal_gen.configs.sample.sampling_params import SamplingParams
 
 
@@ -45,5 +49,23 @@ class TestSamplingParamsValidate(unittest.TestCase):
             SamplingParams(boundary_ratio=math.nan)
 
 
+class TestSamplingParamsSubclass(unittest.TestCase):
+    def test_flux_defaults_resolution_when_not_provided(self):
+        params = FluxSamplingParams()
+
+        self.assertEqual(params.height, 1024)
+        self.assertEqual(params.width, 1024)
+
+    def test_flux_preserves_user_resolution(self):
+        params = FluxSamplingParams(height=640, width=768)
+
+        self.assertEqual(params.height, 640)
+        self.assertEqual(params.width, 768)
+
+    def test_diffusers_generic_calls_base_post_init(self):
+        with self.assertRaises(AssertionError):
+            DiffusersGenericSamplingParams(num_frames=0)
+
+
 if __name__ == "__main__":
     unittest.main()