[diffusion] chore: validate sampling params (#16677)

Co-authored-by: root <root@huchong2-0.huchong2.podvm.svc.cluster.local>

python/sglang/multimodal_gen/test/run_suite.py

@@ -27,6 +27,8 @@ SUITES = {
         "test_lora_format_adapter.py",
         # cli test
         "../cli/test_generate_t2i_perf.py",
+        # unit tests (no server needed)
+        "../test_sampling_params_validate.py",
         # add new 1-gpu test files here
     ],
     "2-gpu": [

python/sglang/multimodal_gen/test/test_sampling_params_validate.py

@@ -0,0 +1,49 @@
+import math
+import unittest
+
+from sglang.multimodal_gen.configs.sample.sampling_params import SamplingParams
+
+
+class TestSamplingParamsValidate(unittest.TestCase):
+    def test_prompt_path_suffix(self):
+        with self.assertRaisesRegex(ValueError, r"prompt_path"):
+            SamplingParams(prompt_path="bad.png")
+
+    def test_num_outputs_per_prompt_must_be_positive(self):
+        with self.assertRaisesRegex(ValueError, r"num_outputs_per_prompt"):
+            SamplingParams(num_outputs_per_prompt=0)
+
+    def test_fps_must_be_positive_int(self):
+        with self.assertRaisesRegex(ValueError, r"\bfps\b"):
+            SamplingParams(fps=0)
+        with self.assertRaisesRegex(ValueError, r"\bfps\b"):
+            SamplingParams(fps=None)  # type: ignore[arg-type]
+
+    def test_num_inference_steps_optional_but_if_set_must_be_positive(self):
+        SamplingParams(num_inference_steps=None)
+        with self.assertRaisesRegex(ValueError, r"num_inference_steps"):
+            SamplingParams(num_inference_steps=-1)
+
+    def test_guidance_scale_must_be_finite_non_negative_if_set(self):
+        SamplingParams(guidance_scale=None)
+        with self.assertRaisesRegex(ValueError, r"guidance_scale"):
+            SamplingParams(guidance_scale=math.nan)
+        with self.assertRaisesRegex(ValueError, r"guidance_scale"):
+            SamplingParams(guidance_scale=-0.1)
+
+    def test_guidance_rescale_must_be_finite_non_negative(self):
+        with self.assertRaisesRegex(ValueError, r"guidance_rescale"):
+            SamplingParams(guidance_rescale=-1.0)
+        with self.assertRaisesRegex(ValueError, r"guidance_rescale"):
+            SamplingParams(guidance_rescale=math.inf)
+
+    def test_boundary_ratio_range(self):
+        SamplingParams(boundary_ratio=None)
+        with self.assertRaisesRegex(ValueError, r"boundary_ratio"):
+            SamplingParams(boundary_ratio=1.5)
+        with self.assertRaisesRegex(ValueError, r"boundary_ratio"):
+            SamplingParams(boundary_ratio=math.nan)
+
+
+if __name__ == "__main__":
+    unittest.main()