SWS-7: Finish "download" workflow template

Make it so the download workflow actually works and does things!

shared/workspaces/workspaces/capability/test/test_helpers.py

+import pytest
+
+from workspaces.capability.enums import CapabilityStepType
+from workspaces.capability.helpers import CapabilityStep, MalformedCapabilityStep
+
+
+def test_capability_step_from_str():
+    """
+    Tests that a capability step can be correctly parsed from a string
+    """
+    step_with_val_and_args = "prepare-and-run-workflow deliver [-r, -l ., shared/workspaces/test/test_data/spool/724126739/17A-109.sb33151331.eb33786546.57892.65940042824]"
+    step_with_val_and_one_arg = "prepare-and-run-workflow null [-g]"
+    step_with_val_and_empty_args = "prepare-and-run-workflow workflow []"
+    step_with_val = "prepare-and-run-workflow name_of_workflow"
+    step_only_type = "await-qa"
+
+    # Step of the form "step-type step-value [step_arg1, ...]"
+    step_with_val_and_args = CapabilityStep.from_str(step_with_val_and_args)
+    assert step_with_val_and_args.step_type is CapabilityStepType.PrepareAndRunWorkflow
+    assert step_with_val_and_args.step_value == "deliver"
+    assert step_with_val_and_args.step_args == [
+        "-r",
+        "-l .",
+        "shared/workspaces/test/test_data/spool/724126739/17A-109.sb33151331.eb33786546.57892.65940042824",
+    ]
+
+    # Step of the form "step-type step-value [step_arg]"
+    step_with_val_and_one_arg = CapabilityStep.from_str(step_with_val_and_one_arg)
+    assert (
+        step_with_val_and_one_arg.step_type is CapabilityStepType.PrepareAndRunWorkflow
+    )
+    assert step_with_val_and_one_arg.step_value == "null"
+    assert step_with_val_and_one_arg.step_args == ["-g"]
+
+    # Step of the form "step-type step-value []"
+    step_with_val_and_empty_args = CapabilityStep.from_str(step_with_val_and_empty_args)
+    assert (
+        step_with_val_and_empty_args.step_type
+        is CapabilityStepType.PrepareAndRunWorkflow
+    )
+    assert step_with_val_and_empty_args.step_value == "workflow"
+    assert step_with_val_and_empty_args.step_args is None
+
+    # Step of the form "step-type step-value"
+    step_with_val = CapabilityStep.from_str(step_with_val)
+    assert step_with_val.step_type is CapabilityStepType.PrepareAndRunWorkflow
+    assert step_with_val.step_value == "name_of_workflow"
+    assert step_with_val.step_args is None
+
+    # Step of the form "step-type"
+    step_only_type = CapabilityStep.from_str(step_only_type)
+    assert step_only_type.step_type is CapabilityStepType.AwaitQA
+    assert step_only_type.step_value is None
+    assert step_only_type.step_args is None
+
+
+def test_capability_step_from_str_error():
+    """
+    Tests that an invalid capability step strings will correctly throw an error
+    """
+    step_empty = ""
+    step_bad_format = "!step.type step$value arg1 arg2 arg3"
+    step_invalid_type = "invalid-step-type step-value [arg1, arg2]"
+
+    with pytest.raises(MalformedCapabilityStep):
+        CapabilityStep.from_str(step_empty)
+        CapabilityStep.from_str(step_bad_format)
+        CapabilityStep.from_str(step_invalid_type)