move common script errors to script so it can keep the error messaging consistent across scripts

spiffworkflow-backend/src/spiffworkflow_backend/scripts/markdown_file_download_link.py

@@ -7,7 +7,6 @@ from spiffworkflow_backend.models.process_model import ProcessModelInfo
 from spiffworkflow_backend.models.script_attributes_context import (
     ScriptAttributesContext,
 )
-from spiffworkflow_backend.scripts.script import ProcessModelIdentifierMissingError
 from spiffworkflow_backend.scripts.script import Script
 
 
@@ -38,10 +37,8 @@ class GetMarkdownFileDownloadLink(Script):
         label = parts[1].split("=")[1]
         process_model_identifier = script_attributes_context.process_model_identifier
         if process_model_identifier is None:
-            raise ProcessModelIdentifierMissingError(
-                "The process model identifier was not given to script"
-                " 'markdown_file_download_link'. This script needs to be run from"
-                " within the context of a process model."
+            raise self.get_proces_model_identifier_is_missing_error(
+                "markdown_file_download_link"
             )
         modified_process_model_identifier = (
             ProcessModelInfo.modify_process_identifier_for_path_param(
@@ -49,6 +46,10 @@ class GetMarkdownFileDownloadLink(Script):
             )
         )
         process_instance_id = script_attributes_context.process_instance_id
+        if process_instance_id is None:
+            raise self.get_proces_instance_id_is_missing_error(
+                "save_process_instance_metadata"
+            )
         url = current_app.config["SPIFFWORKFLOW_BACKEND_URL"]
         url += (
             f"/v1.0/process-data-file-download/{modified_process_model_identifier}/"

spiffworkflow-backend/src/spiffworkflow_backend/scripts/save_process_instance_metadata.py

@@ -8,7 +8,6 @@ from spiffworkflow_backend.models.process_instance_metadata import (
 from spiffworkflow_backend.models.script_attributes_context import (
     ScriptAttributesContext,
 )
-from spiffworkflow_backend.scripts.script import ProcessInstanceIdMissingError
 from spiffworkflow_backend.scripts.script import Script
 
 
@@ -28,10 +27,8 @@ class SaveProcessInstanceMetadata(Script):
         """Run."""
         metadata_dict = args[0]
         if script_attributes_context.process_instance_id is None:
-            raise ProcessInstanceIdMissingError(
-                "The process instance id was not given to script"
-                " 'save_process_instance_metadata'. This script needs to be run from"
-                " within the context of a process instance."
+            raise self.get_proces_instance_id_is_missing_error(
+                "save_process_instance_metadata"
             )
         for key, value in metadata_dict.items():
             pim = ProcessInstanceMetadataModel.query.filter_by(

spiffworkflow-backend/src/spiffworkflow_backend/scripts/script.py

@@ -57,6 +57,26 @@ class Script:
             + "does not properly implement the run function.",
         )
 
+    def get_proces_instance_id_is_missing_error(
+        self, script_name: str
+    ) -> ProcessInstanceIdMissingError:
+        """Return the error so we can raise it from the script and mypy will be happy."""
+        raise ProcessInstanceIdMissingError(
+            "The process instance id was not given to script"
+            f" '{script_name}'. This script needs to be run from"
+            " within the context of a process instance."
+        )
+
+    def get_proces_model_identifier_is_missing_error(
+        self, script_name: str
+    ) -> ProcessModelIdentifierMissingError:
+        """Return the error so we can raise it from the script and mypy will be happy."""
+        return ProcessModelIdentifierMissingError(
+            "The process model identifier was not given to script"
+            f" '{script_name}'. This script needs to be run from"
+            " within the context of a process model."
+        )
+
     @staticmethod
     def requires_privileged_permissions() -> bool:
         """It seems safer to default to True and make safe functions opt in for any user to run them.