add endpoint to reset process to earlier step

spiffworkflow-backend/src/spiffworkflow_backend/api.yml

@@ -1060,6 +1060,39 @@ paths:
               schema:
                 $ref: "#/components/schemas/OkTrue"
 
+  /process-instance-reset/{modified_process_model_identifier}/{process_instance_id}/{spiff_step}:
+    parameters:
+      - name: modified_process_model_identifier
+        in: path
+        required: true
+        description: The modified process model id
+        schema:
+          type: string
+      - name: process_instance_id
+        in: path
+        required: true
+        description: The unique id of an existing process instance.
+        schema:
+          type: integer
+      - name: spiff_step
+        in: query
+        required: false
+        description: Reset the process to this state
+        schema:
+          type: integer
+    post:
+      operationId: spiffworkflow_backend.routes.process_api_blueprint.process_instance_reset
+      summary: Reset a process instance to an earlier step
+      tags:
+        - Process Instances
+      responses:
+        "200":
+          description: Empty ok true response on successful resume.
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/OkTrue"
+
   /process-instances/reports:
     parameters:
       - name: page

spiffworkflow-backend/src/spiffworkflow_backend/routes/process_api_blueprint.py

@@ -651,6 +651,45 @@ def process_instance_resume(
     return Response(json.dumps({"ok": True}), status=200, mimetype="application/json")
 
 
+def process_instance_reset(
+    process_instance_id: int,
+    modified_process_model_identifier: str,
+    spiff_step: int = 0,
+) -> flask.wrappers.Response:
+    process_instance = ProcessInstanceService().get_process_instance(
+        process_instance_id
+    )
+    step_detail = (
+        db.session.query(SpiffStepDetailsModel)
+        .filter(
+            SpiffStepDetailsModel.process_instance_id == process_instance.id,
+            SpiffStepDetailsModel.spiff_step == spiff_step,
+        )
+        .first()
+    )
+    if step_detail is not None and process_instance.bpmn_json is not None:
+        bpmn_json = json.loads(process_instance.bpmn_json)
+        bpmn_json["tasks"] = step_detail.task_json["tasks"]
+        bpmn_json["subprocesses"] = step_detail.task_json["subprocesses"]
+        process_instance.bpmn_json = json.dumps(bpmn_json)
+
+    db.session.add(process_instance)
+    try:
+        db.session.commit()
+    except Exception as e:
+        db.session.rollback()
+        raise ApiError(
+            error_code="reset_process_instance_error",
+            message=f"Could not update the Instance. Original error is {e}",
+        ) from e
+
+    return Response(
+        json.dumps(ProcessInstanceModelSchema().dump(process_instance)),
+        status=200,
+        mimetype="application/json",
+    )
+
+
 def process_instance_log_list(
     modified_process_model_identifier: str,
     process_instance_id: int,

spiffworkflow-frontend/src/hooks/UriListForPermissions.tsx

@@ -16,6 +16,7 @@ export const useUriListForPermissions = () => {
       processInstanceReportListPath: '/v1.0/process-instances/reports',
       processInstanceResumePath: `/v1.0/process-instance-resume/${params.process_model_id}/${params.process_instance_id}`,
       processInstanceSuspendPath: `/v1.0/process-instance-suspend/${params.process_model_id}/${params.process_instance_id}`,
+      processInstanceResetPath: `/v1.0/process-instance-reset/${params.process_model_id}/${params.process_instance_id}`,
       processInstanceTaskListDataPath: `/v1.0/task-data/${params.process_model_id}/${params.process_instance_id}`,
       processInstanceSendEventPath: `/v1.0/send-event/${params.process_model_id}/${params.process_instance_id}`,
       processInstanceCompleteTaskPath: `/v1.0/complete-task/${params.process_model_id}/${params.process_instance_id}`,

spiffworkflow-frontend/src/routes/ProcessInstanceShow.tsx

@@ -90,6 +90,7 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
     [`${targetUris.processInstanceResumePath}`]: ['POST'],
     [`${targetUris.processInstanceSuspendPath}`]: ['POST'],
     [`${targetUris.processInstanceTerminatePath}`]: ['POST'],
+    [targetUris.processInstanceResetPath]: ['POST'],
     [targetUris.messageInstanceListPath]: ['GET'],
     [targetUris.processInstanceActionPath]: ['DELETE'],
     [targetUris.processInstanceLogListPath]: ['GET'],
@@ -261,6 +262,14 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
     return spiffStepLink(<CaretRight />, 1);
   };
 
+  const resetProcessInstance = () => {
+    HttpService.makeCallToBackend({
+      path: `${targetUris.processInstanceResetPath}/${currentSpiffStep()}`,
+      successCallback: refreshPage,
+      httpMethod: 'POST',
+    });
+  };
+
   const getInfoTag = () => {
     if (!processInstance) {
       return null;
@@ -535,6 +544,15 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
     );
   };
 
+  const canResetProcess = (task: any) => {
+    return (
+      processInstance &&
+      processInstance.status === 'suspended' &&
+      task.state === 'READY' &&
+      !showingLastSpiffStep()
+    );
+  };
+
   const getEvents = (task: any) => {
     const handleMessage = (eventDefinition: any) => {
       if (eventDefinition.typename === 'MessageEventDefinition') {
@@ -619,7 +637,7 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
     });
   };
 
-  const taskDataButtons = (task: any) => {
+  const taskDisplayButtons = (task: any) => {
     const buttons = [];
 
     if (
@@ -707,6 +725,16 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
           </Button>
         );
       }
+      if (canResetProcess(task)) {
+        buttons.push(
+          <Button
+            data-qa="reset-process-button"
+            onClick={() => resetProcessInstance()}
+          >
+            Resume Process Here
+          </Button>
+        );
+      }
     }
 
     return buttons;
@@ -771,7 +799,7 @@ export default function ProcessInstanceShow({ variant }: OwnProps) {
         >
           <Stack orientation="horizontal" gap={2}>
             {taskToUse.name} ({taskToUse.type}): {taskToUse.state}
-            {taskDataButtons(taskToUse)}
+            {taskDisplayButtons(taskToUse)}
           </Stack>
           {selectingEvent
             ? eventSelector(candidateEvents)