Remove single List[str] input handling in serving_embedding.py

- The handling for a single string in a list can be removed as #7396 is merged.
- Add UT cases in test_openai_server for such case

Author: CatherineSue

python/sglang/srt/entrypoints/openai/serving_embedding.py

@@ -79,11 +79,7 @@ def _convert_to_internal_request(
             prompt_kwargs = {"text": prompt}
         elif isinstance(prompt, list):
             if len(prompt) > 0 and isinstance(prompt[0], str):
-                # List of strings - if it's a single string in a list, treat as single string
-                if len(prompt) == 1:
-                    prompt_kwargs = {"text": prompt[0]}
-                else:
-                    prompt_kwargs = {"text": prompt}
+                prompt_kwargs = {"text": prompt}
             elif len(prompt) > 0 and isinstance(prompt[0], MultimodalEmbeddingInput):
                 # Handle multimodal embedding inputs
                 texts = []

test/srt/test_openai_server.py

@@ -535,6 +535,31 @@ def test_embedding_batch(self):
         self.assertTrue(len(response.data[0].embedding) > 0)
         self.assertTrue(len(response.data[1].embedding) > 0)
 
+    def test_embedding_single_batch_str(self):
+        """Test embedding with a List[str] and length equals to 1"""
+        client = openai.Client(api_key=self.api_key, base_url=self.base_url)
+        response = client.embeddings.create(model=self.model, input=["Hello world"])
+        self.assertEqual(len(response.data), 1)
+        self.assertTrue(len(response.data[0].embedding) > 0)
+
+    def test_embedding_single_int_list(self):
+        """Test embedding with a List[int] or List[List[int]]]"""
+        client = openai.Client(api_key=self.api_key, base_url=self.base_url)
+        response = client.embeddings.create(
+            model=self.model,
+            input=[[15339, 314, 703, 284, 612, 262, 10658, 10188, 286, 2061]],
+        )
+        self.assertEqual(len(response.data), 1)
+        self.assertTrue(len(response.data[0].embedding) > 0)
+
+        client = openai.Client(api_key=self.api_key, base_url=self.base_url)
+        response = client.embeddings.create(
+            model=self.model,
+            input=[15339, 314, 703, 284, 612, 262, 10658, 10188, 286, 2061],
+        )
+        self.assertEqual(len(response.data), 1)
+        self.assertTrue(len(response.data[0].embedding) > 0)
+
     def test_empty_string_embedding(self):
         """Test embedding an empty string."""