Fix optional inputs with None/empty string values in job submissions

sdk/ml/azure-ai-ml/CHANGELOG.md

@@ -6,6 +6,8 @@
 
 ### Bugs Fixed
 
+- Fixed issue where optional string inputs with `None` or empty string values would fail with "The Value field is required" error. Optional inputs with `None` or empty string values are now correctly excluded from REST API requests, allowing the backend to use default values from component definitions.
+
 ### Other Changes
 
 

sdk/ml/azure-ai-ml/azure/ai/ml/entities/_job/_input_output_helpers.py

@@ -271,17 +271,30 @@ def to_rest_dataset_literal_inputs(
                             error_type=ValidationErrorType.INVALID_VALUE,
                         )
             elif input_value is None:
-                # If the input is None, we need to pass the origin None to the REST API
-                input_data = LiteralJobInput(value=None)
+                # Skip None values for optional inputs - they should not be sent to REST API
+                # The backend will use the default value from the component definition if one exists
+                continue
             else:
                 # otherwise, the input is a literal input
                 if isinstance(input_value, dict):
-                    input_data = LiteralJobInput(value=str(input_value["value"]))
+                    dict_value = input_value["value"]
+                    # Skip None values for optional inputs
+                    if dict_value is None:
+                        continue
+                    value_str = str(dict_value)
+                    # Skip empty strings for optional inputs - they should not be sent to REST API
+                    if value_str == "":
+                        continue
+                    input_data = LiteralJobInput(value=value_str)
                     # set mode attribute manually for binding job input
                     if "mode" in input_value:
                         input_data.mode = input_value["mode"]
                 else:
-                    input_data = LiteralJobInput(value=str(input_value))
+                    value_str = str(input_value)
+                    # Skip empty strings for optional inputs - they should not be sent to REST API
+                    if value_str == "":
+                        continue
+                    input_data = LiteralJobInput(value=value_str)
                 input_data.job_input_type = JobInputType.LITERAL
             # Pack up inputs into PipelineInputs or ComponentJobInputs depending on caller
             rest_inputs[input_name] = input_data

sdk/ml/azure-ai-ml/tests/command_job/unittests/test_command_job_entity.py

@@ -243,3 +243,91 @@ def test_single_docker_args_job_serialization(self) -> None:
         assert job_prop.resources.locations == ["westus"]
         assert hasattr(job_prop.resources, "docker_args_list") == False
         assert from_rest_job.resources.docker_args == "--shm-size=1g"
+
+    def test_optional_inputs_with_none_and_empty_string(self) -> None:
+        """Test that optional inputs with None or empty string values are not sent to REST API."""
+        # Test with None value - should be excluded from REST inputs
+        inputs_with_none = {
+            "required_input": "value1",
+            "optional_input": None,
+        }
+        command_job = CommandJob(
+            display_name="test-optional-inputs",
+            command='echo "hello world"',
+            environment="AzureML-Minimal:1",
+            compute="cpu-cluster",
+            inputs=inputs_with_none,
+        )
+        rest_obj = command_job._to_rest_object()
+        # None values should not be in the REST inputs
+        assert "required_input" in rest_obj.properties.inputs
+        assert "optional_input" not in rest_obj.properties.inputs
+
+        # Test with empty string value - should be excluded from REST inputs
+        inputs_with_empty_string = {
+            "required_input": "value1",
+            "optional_input": "",
+        }
+        command_job_empty = CommandJob(
+            display_name="test-optional-inputs-empty",
+            command='echo "hello world"',
+            environment="AzureML-Minimal:1",
+            compute="cpu-cluster",
+            inputs=inputs_with_empty_string,
+        )
+        rest_obj_empty = command_job_empty._to_rest_object()
+        # Empty string values should not be in the REST inputs
+        assert "required_input" in rest_obj_empty.properties.inputs
+        assert "optional_input" not in rest_obj_empty.properties.inputs
+
+        # Test with non-empty value - should be included in REST inputs
+        inputs_with_value = {
+            "required_input": "value1",
+            "optional_input": "value2",
+        }
+        command_job_value = CommandJob(
+            display_name="test-optional-inputs-value",
+            command='echo "hello world"',
+            environment="AzureML-Minimal:1",
+            compute="cpu-cluster",
+            inputs=inputs_with_value,
+        )
+        rest_obj_value = command_job_value._to_rest_object()
+        # Non-empty values should be in the REST inputs
+        assert "required_input" in rest_obj_value.properties.inputs
+        assert "optional_input" in rest_obj_value.properties.inputs
+        assert rest_obj_value.properties.inputs["optional_input"].value == "value2"
+
+        # Test with dict containing None value - should be excluded from REST inputs
+        inputs_with_dict_none = {
+            "required_input": "value1",
+            "optional_input": {"value": None},
+        }
+        command_job_dict_none = CommandJob(
+            display_name="test-optional-inputs-dict-none",
+            command='echo "hello world"',
+            environment="AzureML-Minimal:1",
+            compute="cpu-cluster",
+            inputs=inputs_with_dict_none,
+        )
+        rest_obj_dict_none = command_job_dict_none._to_rest_object()
+        # Dict with None value should not be in the REST inputs
+        assert "required_input" in rest_obj_dict_none.properties.inputs
+        assert "optional_input" not in rest_obj_dict_none.properties.inputs
+
+        # Test with dict containing empty string - should be excluded from REST inputs
+        inputs_with_dict_empty = {
+            "required_input": "value1",
+            "optional_input": {"value": ""},
+        }
+        command_job_dict_empty = CommandJob(
+            display_name="test-optional-inputs-dict-empty",
+            command='echo "hello world"',
+            environment="AzureML-Minimal:1",
+            compute="cpu-cluster",
+            inputs=inputs_with_dict_empty,
+        )
+        rest_obj_dict_empty = command_job_dict_empty._to_rest_object()
+        # Dict with empty string should not be in the REST inputs
+        assert "required_input" in rest_obj_dict_empty.properties.inputs
+        assert "optional_input" not in rest_obj_dict_empty.properties.inputs