Fix bug with detections offset and cover problem with additional test

inference/core/workflows/core_steps/transformations/detection_offset/v1.py

@@ -131,6 +131,8 @@ def offset_detections(
     parent_id_key: str = PARENT_ID_KEY,
     detection_id_key: str = DETECTION_ID_KEY,
 ) -> sv.Detections:
+    if len(detections) == 0:
+        return detections
     _detections = deepcopy(detections)
     _detections.xyxy = np.array(
         [

tests/workflows/unit_tests/core_steps/transformations/test_detection_offset.py

@@ -107,3 +107,18 @@ def test_offset_detection() -> None:
     assert result["detection_id"] != str(
         detections["parent_id"][0]
     ), "New detection id (random) must be assigned"
+
+
+def test_offset_detection_when_nothing_predicted() -> None:
+    # given
+    detections = sv.Detections.empty()
+
+    # when
+    result = offset_detections(
+        detections=detections,
+        offset_width=50,
+        offset_height=100,
+    )
+
+    # then
+    assert len(detections) == 0, "Expected empty detections in output"

tests/workflows/unit_tests/execution_engine/dynamic_blocs/test_block_scaffolding.py

@@ -116,6 +116,42 @@ def run_function(self, a, b) -> BlockResult:
     }, "Expected result of 3 + 5 + 6 (last value from init)"
 
 
+def test_assembly_custom_python_block_when_init_not_provided() -> None:
+    # given
+    manifest = BlockManifest
+    run_function = """
+def run_function(self, a, b) -> BlockResult:
+    return {"result": a + b + len(self._init_results)}
+    """
+    python_code = PythonCode(
+        type="PythonCode",
+        run_function_code=run_function,
+        run_function_name="run_function",
+        imports=["import math"],
+    )
+
+    # when
+    workflow_block_class = assembly_custom_python_block(
+        block_type_name="some",
+        unique_identifier="unique-id",
+        manifest=manifest,
+        python_code=python_code,
+    )
+    workflow_block_instance = workflow_block_class()
+    execution_result = workflow_block_instance.run(a=3, b=5)
+
+    # then
+    assert (
+        workflow_block_class.get_init_parameters() == []
+    ), "Expected no init parameters defined"
+    assert (
+        workflow_block_class.get_manifest() == BlockManifest
+    ), "Expected manifest to be returned"
+    assert execution_result == {
+        "result": 8
+    }, "Expected result of 3 + 5 + 0 (last value from init)"
+
+
 def test_assembly_custom_python_block_when_run_function_not_found() -> None:
     # given
     manifest = BlockManifest