Express Credit Check Workflow

Recreating Issue

Start Server & Mongo

pnpm install
docker compose up -d
pnpm start

Manual Using Curl

Initialize a workflow

curl --request POST \
  --url http://localhost:4242/workflows \
  --header 'Content-Type: application/json'

Submit a "SUBMIT" event, using the workflowId obtained from the previous step

curl --request POST \
  --url http://localhost:4242/workflows/o8bls8 \
  --header 'Content-Type: application/json' \
  --data '{ "type": "SUBMIT" }'

Check if the PENDING state is saved

curl --request GET \
  --url http://localhost:4242/workflows/o8bls8 \
  --header 'Content-Type: application/json'

Submit an "APPROVE" event, using the same

curl --request POST \
  --url http://localhost:4242/workflows/o8bls8 \
  --header 'Content-Type: application/json' \
  --data '{ "type": "APPROVE" }'

Check if the APPROVED final state is saved

curl --request GET \
  --url http://localhost:4242/workflows/o8bls8 \
  --header 'Content-Type: application/json'

Using Script

node -r esbuild-register race-condition.ts 0 100

Original README Contents

This is a simple workflow engine built with:

• XState v5
• TypeScript
• Express

This is a modified version of the express-workflow project that shows how to implement state hydration in the actorService.ts file. It also uses a more complex machine with guards, actions, and parallel states configured.

NOTE: This project is not production-ready and is intended for educational purposes.

Usage

MongoDB should be configured with a database named creditCheck.

Use docker compose up -d to have a database with creditCheck included.

We recommend installing the MongoDB Compass app to view the contents of your database while you run this project.

Add the connection string to the DB client in the actorService.ts file by updating this line:

const uri = "<your mongo uri here>";

pnpm install
pnpm start

Endpoints

POST /workflows

Creates a new workflow instance.

curl -X POST http://localhost:4242/workflows

Example response: 201 - Created

{
  {"message":"New worflow created successfully","workflowId":"uzkjyy"}
}

POST /workflows/:id

200 - OK

Sends an event to a workflow instance.

# Replace :id with the workflow ID; e.g. http://localhost:4242/workflows/7ky252
# the body should be JSON
curl -X POST http://localhost:4242/workflows/:id -d '{"type": "Submit", "SSN": "123456789", "lastName": "Bauman", "firstName": "Gavin"}' -H "Content-Type: application/json"

GET /workflows/:id

Gets the current state of a workflow instance.

curl -X GET http://localhost:4242/workflows/:id

CURLS

Initialize workflow:

curl --request POST \
  --url http://localhost:4242/workflows
  -H "Content-Type: application/json"

Send Event (send SUBMIT then APPROVE - can have saving issue at either event):

curl --request POST \
  --url http://localhost:4242/workflows/vcrtyr \
  --data '{"type": "APPROVE"}'
  -H "Content-Type: application/json"

Get Saved Status:

curl --request GET \
  --url http://localhost:4242/workflows/vcrtyr
  -H "Content-Type: application/json"