[Bugfix] remove fallback in guided_json (int range, patterns) (#16725)

Signed-off-by: csy1204 <josang1204@gmail.com>
Co-authored-by: 조상연[플레이스 AI] <sang-yeon.cho@navercorp.com>

tests/entrypoints/llm/test_guided_generate.py

@@ -305,7 +305,7 @@ def test_disable_guided_decoding_fallback(sample_regex, llm):
     with pytest.raises(
             ValueError,
             match="xgrammar does not support advanced JSON schema features "
-            "like enums, patterns or numeric ranges."):
+            "like string length, item limits, or property bounds."):
         llm.generate(prompts="This should fail",
                      sampling_params=sampling_params,
                      use_tqdm=True)
@@ -386,6 +386,62 @@ def test_guided_json_completion_with_enum(llm, guided_decoding_backend: str):
         jsonschema.validate(instance=output_json, schema=json_schema)
 
 
+@pytest.mark.skip_global_cleanup
+@pytest.mark.parametrize("guided_decoding_backend", GUIDED_DECODING_BACKENDS)
+def test_guided_number_range_json_completion(llm,
+                                             guided_decoding_backend: str):
+    sample_output_schema = {
+        "type": "object",
+        "properties": {
+            "age": {
+                "type": "integer",
+                "minimum": 18,
+                "maximum": 99
+            },
+            "score": {
+                "type": "number",
+                "minimum": 0.0,
+                "maximum": 100.0
+            },
+            "zipcode": {
+                "type": "string",
+                "pattern": r"^\d{5}(-\d{4})?$"
+            },
+        },
+        "required": ["age", "score", "zipcode"],
+    }
+    sampling_params = SamplingParams(
+        temperature=1.0,
+        max_tokens=1000,
+        guided_decoding=GuidedDecodingParams(json=sample_output_schema,
+                                             backend=guided_decoding_backend),
+    )
+    outputs = llm.generate(
+        prompts=[
+            "Create a JSON object for a user with age, score, and zipcode."
+        ] * 2,
+        sampling_params=sampling_params,
+        use_tqdm=True,
+    )
+
+    assert outputs is not None
+
+    for output in outputs:
+        assert output is not None
+        assert isinstance(output, RequestOutput)
+        prompt = output.prompt
+
+        generated_text = output.outputs[0].text
+        assert generated_text is not None
+        print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
+        output_json = json.loads(generated_text)
+        jsonschema.validate(instance=output_json, schema=sample_output_schema)
+        assert 18 <= output_json["age"] <= 99
+        assert 0.0 <= output_json["score"] <= 100.0
+        assert (re.fullmatch(r"^\d{5}(-\d{4})?$", output_json["zipcode"])
+                is not None)
+
+
 @pytest.mark.skip_global_cleanup
 def test_guidance_no_additional_properties(llm):
     schema = {

tests/v1/entrypoints/conftest.py

@@ -47,6 +47,14 @@ def sample_json_schema():
                     "type": "string",
                 }
             },
+            "grade": {
+                "type": "string",
+                "pattern": "^[A-D]$"  # Regex pattern
+            },
+            "email": {
+                "type": "string",
+                "pattern": "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$"
+            },
             "work_history": {
                 "type": "array",
                 "items": {
@@ -56,17 +64,20 @@ def sample_json_schema():
                             "type": "string"
                         },
                         "duration": {
-                            "type": "number"
+                            "type": "number",
+                            "minimum": 0.0,
+                            "maximum": 100.0,  # Numeric range
                         },
                         "position": {
                             "type": "string"
                         }
                     },
-                    "required": ["company", "position"]
+                    "required": ["company", "duration", "position"]
                 }
             }
         },
-        "required": ["name", "age", "skills", "work_history"]
+        "required":
+        ["name", "age", "skills", "grade", "email", "work_history"]
     }
 
 
@@ -78,27 +89,18 @@ def unsupported_json_schema():
         "properties": {
             "score": {
                 "type": "integer",
-                "minimum": 0,
+                "multipleOf": 5  # Numeric multiple
-                "maximum": 100  # Numeric range
-            },
-            "grade": {
-                "type": "string",
-                "pattern": "^[A-D]$"  # Regex pattern
-            },
-            "email": {
-                "type": "string",
-                "pattern": "^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$"
             },
             "tags": {
                 "type": "array",
                 "items": {
                     "type": "string",
-                    "pattern":
+                    "minLength": 10,
-                    "^[a-z]{1,10}$"  # Combining length and pattern restrictions
+                    "maxLength": 20
                 }
             }
         },
-        "required": ["score", "grade", "email", "tags"]
+        "required": ["score", "tags"]
     }
 
 

tests/v1/structured_output/test_utils.py

@@ -9,10 +9,6 @@ from vllm.v1.structured_output.backend_xgrammar import (
 @pytest.fixture
 def unsupported_string_schemas():
     return [
-        {
-            "type": "string",
-            "pattern": "^[a-zA-Z]+$"
-        },
         {
             "type": "string",
             "format": "email"
@@ -23,22 +19,6 @@ def unsupported_string_schemas():
 @pytest.fixture
 def unsupported_integer_schemas():
     return [
-        {
-            "type": "integer",
-            "minimum": 0
-        },
-        {
-            "type": "integer",
-            "maximum": 120
-        },
-        {
-            "type": "integer",
-            "exclusiveMinimum": 120
-        },
-        {
-            "type": "integer",
-            "exclusiveMaximum": 120
-        },
         {
             "type": "integer",
             "multipleOf": 120
@@ -49,22 +29,6 @@ def unsupported_integer_schemas():
 @pytest.fixture
 def unsupported_number_schemas():
     return [
-        {
-            "type": "number",
-            "minimum": 0
-        },
-        {
-            "type": "number",
-            "maximum": 120
-        },
-        {
-            "type": "number",
-            "exclusiveMinimum": 120
-        },
-        {
-            "type": "number",
-            "exclusiveMaximum": 120
-        },
         {
             "type": "number",
             "multipleOf": 120
@@ -156,13 +120,28 @@ def supported_schema():
                 "type": "string",
                 "enum": ["sedan", "suv", "truck"]
             },
+            "car_brand": {
+                "type": "string",
+                "pattern": "^[a-zA-Z]+$"
+            },
             "short_description": {
                 "type": "string",
                 "maxLength": 50
             },
+            "mileage": {
+                "type": "number",
+                "minimum": 0,
+                "maximum": 1000000
+            },
+            "model_year": {
+                "type": "integer",
+                "exclusiveMinimum": 1900,
+                "exclusiveMaximum": 2100
+            },
             "long_description": {
                 "type": "string",
-                "minLength": 50
+                "minLength": 50,
+                "maxLength": 2000
             },
             "address": {
                 "type": "object",

vllm/model_executor/guided_decoding/__init__.py

@@ -65,7 +65,7 @@ def maybe_backend_fallback(
             fallback_or_error(
                 guided_params,
                 "xgrammar does not support advanced JSON schema features like "
-                "enums, patterns or numeric ranges.", "outlines")
+                "string length, item limits, or property bounds.", "outlines")
 
         # xgrammar only supports GBNF grammars, so we must convert Lark.
         # We must check if the grammar is likely Lark and if that

vllm/model_executor/guided_decoding/utils.py

@@ -10,16 +10,8 @@ def has_xgrammar_unsupported_json_features(schema: dict) -> bool:
         if not isinstance(obj, dict):
             return False
 
-        # Check for pattern restrictions
-        if "pattern" in obj:
-            return True
-
         # Check for numeric ranges
-        if obj.get("type") in ("integer", "number") and any(
+        if obj.get("type") in ("integer", "number") and ("multipleOf" in obj):
-                key in obj for key in [
-                    "minimum", "maximum", "exclusiveMinimum",
-                    "exclusiveMaximum", "multipleOf"
-                ]):
             return True
 
         # Check for array unsupported keywords

vllm/v1/structured_output/backend_xgrammar.py

@@ -179,15 +179,8 @@ def has_xgrammar_unsupported_json_features(schema: dict[str, Any]) -> bool:
         if not isinstance(obj, dict):
             return False
 
-        # Check for pattern restrictions
-        if "pattern" in obj:
-            return True
-
         # Check for numeric ranges
-        if obj.get("type") in ("integer", "number") and any(
+        if obj.get("type") in ("integer", "number") and ("multipleOf" in obj):
-                key in obj
-                for key in ("minimum", "maximum", "exclusiveMinimum",
-                            "exclusiveMaximum", "multipleOf")):
             return True
 
         # Check for array unsupported keywords