diff --git a/tests/unit/sagemaker/workflow/helpers.py b/tests/unit/sagemaker/workflow/helpers.py
index 5fdc30f8ba..67405e9372 100644
--- a/tests/unit/sagemaker/workflow/helpers.py
+++ b/tests/unit/sagemaker/workflow/helpers.py
@@ -41,7 +41,10 @@ def __init__(self, name, display_name=None, description=None, depends_on=None):
         super(CustomStep, self).__init__(
             name, display_name, description, StepTypeEnum.TRAINING, depends_on
         )
-        self._properties = Properties(path=f"Steps.{name}")
+        # for testing property reference, we just use DescribeTrainingJobResponse shape here.
+        self._properties = Properties(
+            path=f"Steps.{name}", shape_name="DescribeTrainingJobResponse"
+        )
 
     @property
     def arguments(self):
diff --git a/tests/unit/sagemaker/workflow/test_transform_step.py b/tests/unit/sagemaker/workflow/test_transform_step.py
index ee5c27f757..2a75349d56 100644
--- a/tests/unit/sagemaker/workflow/test_transform_step.py
+++ b/tests/unit/sagemaker/workflow/test_transform_step.py
@@ -23,10 +23,13 @@
 from sagemaker.parameter import IntegerParameter
 from sagemaker.tuner import HyperparameterTuner
 from sagemaker.workflow.pipeline_context import PipelineSession
+from tests.unit.sagemaker.workflow.helpers import CustomStep
 
 from sagemaker.workflow.steps import TransformStep, TransformInput
 from sagemaker.workflow.pipeline import Pipeline
 from sagemaker.workflow.parameters import ParameterString
+from sagemaker.workflow.functions import Join
+from sagemaker.workflow import is_pipeline_variable
 
 from sagemaker.transformer import Transformer
 
@@ -53,6 +56,7 @@ def client():
     client_mock._client_config.user_agent = (
         "Boto3/1.14.24 Python/3.8.5 Linux/5.4.0-42-generic Botocore/1.17.24 Resource"
     )
+    client_mock.describe_model.return_value = {"PrimaryContainer": {}, "Containers": {}}
     return client_mock
 
 
@@ -80,18 +84,44 @@ def pipeline_session(boto_session, client):
     )
 
 
-def test_transform_step_with_transformer(pipeline_session):
-    model_name = ParameterString("ModelName")
+@pytest.mark.parametrize(
+    "model_name",
+    [
+        "my-model",
+        ParameterString("ModelName"),
+        ParameterString("ModelName", default_value="my-model"),
+        Join(on="-", values=["my", "model"]),
+        CustomStep(name="custom-step").properties.RoleArn,
+    ],
+)
+@pytest.mark.parametrize(
+    "data",
+    [
+        "s3://my-bucket/my-data",
+        ParameterString("MyTransformInput"),
+        ParameterString("MyTransformInput", default_value="s3://my-model"),
+        Join(on="/", values=["s3://my-bucket", "my-transform-data", "input"]),
+        CustomStep(name="custom-step").properties.OutputDataConfig.S3OutputPath,
+    ],
+)
+@pytest.mark.parametrize(
+    "output_path",
+    [
+        "s3://my-bucket/my-output-path",
+        ParameterString("MyOutputPath"),
+        ParameterString("MyOutputPath", default_value="s3://my-output"),
+        Join(on="/", values=["s3://my-bucket", "my-transform-data", "output"]),
+        CustomStep(name="custom-step").properties.OutputDataConfig.S3OutputPath,
+    ],
+)
+def test_transform_step_with_transformer(model_name, data, output_path, pipeline_session):
     transformer = Transformer(
         model_name=model_name,
         instance_type="ml.m5.xlarge",
         instance_count=1,
-        output_path=f"s3://{pipeline_session.default_bucket()}/Transform",
+        output_path=output_path,
         sagemaker_session=pipeline_session,
     )
-    data = ParameterString(
-        name="Data", default_value=f"s3://{pipeline_session.default_bucket()}/batch-data"
-    )
     transform_inputs = TransformInput(data=data)
 
     with warnings.catch_warnings(record=True) as w:
@@ -123,13 +153,27 @@ def test_transform_step_with_transformer(pipeline_session):
         parameters=[model_name, data],
         sagemaker_session=pipeline_session,
     )
-    step_args.args["ModelName"] = model_name.expr
-    step_args.args["TransformInput"]["DataSource"]["S3DataSource"]["S3Uri"] = data.expr
-    assert json.loads(pipeline.definition())["Steps"][0] == {
-        "Name": "MyTransformStep",
-        "Type": "Transform",
-        "Arguments": step_args.args,
-    }
+    step_args = step_args.args
+    step_def = json.loads(pipeline.definition())["Steps"][0]
+    step_args["ModelName"] = model_name.expr if is_pipeline_variable(model_name) else model_name
+    step_args["TransformInput"]["DataSource"]["S3DataSource"]["S3Uri"] = (
+        data.expr if is_pipeline_variable(data) else data
+    )
+    step_args["TransformOutput"]["S3OutputPath"] = (
+        output_path.expr if is_pipeline_variable(output_path) else output_path
+    )
+
+    del (
+        step_args["ModelName"],
+        step_args["TransformInput"]["DataSource"]["S3DataSource"]["S3Uri"],
+        step_args["TransformOutput"]["S3OutputPath"],
+    )
+    del (
+        step_def["Arguments"]["ModelName"],
+        step_def["Arguments"]["TransformInput"]["DataSource"]["S3DataSource"]["S3Uri"],
+        step_def["Arguments"]["TransformOutput"]["S3OutputPath"],
+    )
+    assert step_def == {"Name": "MyTransformStep", "Type": "Transform", "Arguments": step_args}
 
 
 @pytest.mark.parametrize(