User credentials authentication + MFA solved

[LuisFalcon003]

I've been using sp-rest-proxy for the last 8 years through user credentials authentication strategy (username and password), then MFA came in for security reasons and I couldn't run the proxy in my local enviroment anymore. I tried setting up PnP library authentication directly in my projects and get away from sp-rest-proxy, but it requires changes far from configuration. After trial and error, I ended up with the following steps in order to keep using sp-rest-proxy with username and password + MFA in my Angular and React projects:

- delete node_modules
- delete package-lock.json
- delete electron, sp-rest-proxy, node-sp-auth and node-sp-auth-config from package.json
- npm cache clean --force
- npm install --force
- npm install electron@8 --save-dev --legacy-peer-deps
- npm install sp-rest-proxy@3.3.2 --force
- npm install node-sp-auth@3.0.4 --force
- npm install node-sp-auth-config@3.0.2 --force
- npm run proxy
- select On-Demand credentials
- Enter the proxy path in the browser (I use http://localhost:8080)
- For testing, enter a relative SharePoint endpoint: /_api/web
- Select GET HTTP Method, then click Send HTTP request. It will pop up the login using Electron.
- Enter your username and password + MFA
- Do not keep the session, select NO. Otherwise, you won't be able to connect to other SharePoint site for other projects until deleting the cache folder.
- The endpoint response shows up.
- Proceed launching your project.

SOME GOTCHAS:

1. Unable to find Electron app at D:\2.Projects\ABC

   Cannot find module 'D:\2.Projects\ABC'
   Require stack:

   • D:\2.Projects\ABC SGD\Sources\ABC-Frontend\node_modules\electron\dist\resources\default_app...\main.js

SOLUTION: The project's full path folder name has spaces (in this case: "ABC SGD"). Avoid spaces in your folder name. Make sure all your parent folders from the root folder have no spaces.

2. Proxy Error: Cannot read properties of undefined (reading 'toString')

Or a json error in the proxy sever (e.g.: http://localhost:8080/ ):

{
"readyState": 4,
"responseText": "Proxy Error: Cannot read properties of undefined (reading 'toString') (see more in sp-rest-proxy console)",
"status": 400,
"statusText": "Bad Request"
}

SOLUTION: This indicates a failure in the interactive authentication process using the OnDemandCredentials strategy.
The OnDemandCredentials strategy requires a tool like Electron or a web browser instance to pop up, allowing you to manually enter your SharePoint credentials. Since the proxy is crashing with a JavaScript error, it means this interactive sign-in mechanism is failing before it can complete. Re-install sp-rest-proxy, node-sp-auth and node-sp-auth-config or even better run all steps above.

3. "-21470224891 System.UnauthorizedAccessException", "message":{"lang":"\es-ES","value":"Attempted to perform a….}

SOLUTION: This error occurs when a sticky session persist from a previous login, most likely because you selected the option to persist the session. Execute %appdata% or C:\Users<your-user>\AppData\Roaming, then delete Electron folder.

4. Useful to delete all cached files from C:\Users<your-user>\AppData\Roaming\spauth\ondemand

Happy coding!