[diffusion] feat: Add --model-id for config resolution; deprecate model_detectors (#19607)

python/sglang/multimodal_gen/test/run_suite.py

@@ -34,6 +34,7 @@ SUITES = {
         "../unit/test_sampling_params_validate.py",
         "../unit/test_storage.py",
         "../unit/test_lora_format_adapter.py",
+        "../unit/test_server_args_unit.py",
         # add new unit tests here
     ],
     "1-gpu": [

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

@@ -0,0 +1,50 @@
+import os
+import unittest
+
+from sglang.multimodal_gen.registry import _get_config_info
+from sglang.multimodal_gen.runtime.server_args import ServerArgs
+
+
+class TestServerArgsPathExpansion(unittest.TestCase):
+    def test_tilde_model_path_is_expanded(self):
+        args = ServerArgs.from_dict({"model_path": "~/fake/local/model"})
+        expected = os.path.expanduser("~/fake/local/model")
+        self.assertEqual(args.model_path, expected)
+        self.assertFalse(args.model_path.startswith("~"))
+
+    def test_absolute_path_is_unchanged(self):
+        args = ServerArgs.from_dict({"model_path": "/data/my-model"})
+        self.assertEqual(args.model_path, "/data/my-model")
+
+
+class TestModelIdResolution(unittest.TestCase):
+    def setUp(self):
+        _get_config_info.cache_clear()
+
+    def test_model_id_overrides_arbitrary_local_path(self):
+        # a local path whose directory name does not match any HF repo name;
+        # --model-id tells the engine which config to use
+        info = _get_config_info("/data/my-custom-qwen", model_id="Qwen-Image")
+        self.assertIsNotNone(info)
+        from sglang.multimodal_gen.configs.pipeline_configs.qwen_image import (
+            QwenImagePipelineConfig,
+        )
+
+        self.assertIs(info.pipeline_config_cls, QwenImagePipelineConfig)
+
+    def test_model_id_works_after_tilde_expansion(self):
+        # simulate the full flow: user passes ~/..., engine expands and resolves
+        expanded = os.path.expanduser("~/.cache/huggingface/hub/bbb/snapshots/ccc")
+        _get_config_info.cache_clear()
+        info = _get_config_info(expanded, model_id="Qwen-Image")
+        self.assertIsNotNone(info)
+
+    def test_model_id_unknown_falls_back_without_crash(self):
+        # unrecognized model_id: should warn and fall back to path-based detection
+        # with an unresolvable path, expect RuntimeError from the detector step
+        with self.assertRaises((RuntimeError, Exception)):
+            _get_config_info("/data/no-such-model", model_id="NonExistentModelXYZ")
+
+
+if __name__ == "__main__":
+    unittest.main()