MediatR VS ua-parser-js

You probably noticed that .SetName() returns a Either. You may have come across Unit in libraries like MediatR or Language-Ext. It's a simple construct representing a type with only one possible value. We use it as a placeholder for operations that do not return a value but may return another state. In our example, .SetName() is a Command that does not return a value but may fail. Therefore, the monad Either carries two possible states: Right (without value) or Left (with an Error).

The widely used MediatR library[0] could be used to do that as well, just FYI.

[0]: https://github.com/jbogard/MediatR

Hope this GH issue shed some light on why injecting handler inside another handler is not good https://github.com/jbogard/MediatR/issues/400

From: https://github.com/jbogard/MediatR

I gave it a go and I was impressed how easy and fast it was to set it all up. Since I'm not a big fan of REPR pattern almost all my projects are using CQRS pattern with a help of MediatR ](https://github.com/jbogard/MediatR) I immediately started going over something similar that Fast Endpoints offer which is a command bus.

I'd use a dedicated event bus based on Reactive Extensions or MediatR to publish domain events from your domain services. This probably doesn't solve all your ViewModel update problems as is, maybe you need to revise the granularity (maybe you can have smaller ViewModels that refresh single property that exposes the Model) and lifespan (sometimes you can create a ViewModel, make it perform it's task and then discard it completely) of your ViewModels.

If you're finding yourself in a situation where you need to turn this behavior into a pattern because there are a lot of View Models that need to execute async business logic in response to some changes, I'd go with something like MediatR or Reactive Extensions. The idea is, again, that some other, probably business-level, component listens to changes in a decoupled way (that means it doesn't subscribe directly to your View Model, but to an event bus instead). View Model publishes change events to the event bus, and business-component reacts to these events by executing the business logic.

What people really want is to design the logic of an app independently from the component hierarchy. That means you need to store state somewhere other than the components and you need to dispatch events that are not attached to the component hierarchy. Also, a one way data flow has well known benefits as described by things like CQRS, RabbitMQ, and MediatR.

Just look at all the big companies doing it

https://faisalman.github.io/ua-parser-js/

This project is backed under MIT License, special shout out to project UA-Parser, as liguard uses a piece of its source-code.

With NPM, what's actually published is not what's in the git repo, so it's harder to inspect/review vulnerabilities or hijacking. With composer, what's in git _is_ what composer pulls (with the exception of rules in .gitattributes to exclude files etc), making it much easier to trace. One such example: https://github.com/faisalman/ua-parser-js/issues/536

Composer packages are vendor namespaced, so hijacking an abandoned package is not possible (and it is with NPM), some examples like https://www.theregister.com/2021/08/10/github_npm_package/

Sure, I suppose in theory it could happen with other ecosystems, but for some reason it doesn't. It sure seems to just keep happening in NPM though.

From the other side, npm package may be hijacked(as it happened recently for ua-parser-js and to other packages earlier). To mitigate that, I don't know, probably, subscribing to some security digest would be the most helpful.

On Oct. 22, 2021, developers of a very common NPM package, ua-parser-js, discovered that some attackers uploaded a compromised version of the package containing malware for Linux and Windows, and were capable of stealing data (at least passwords and cookies from the browser).

Since Neovim 0.5 release (which has full Lua support) I see more and more amazing Lua plugins being developed, and I think this trend will likely to continue. But I recently got more concerned about security risks associated with the way Neovim plugins being installed and used (especially after seeing recent compromises like ua-parser-js or coa). Installing typical Neovim plugin is basically downloading and executing random code from the internet on your machine with your user privileges, so hijacked or deliberately malicious plugin could potentially do a lot of damage (like stealing keys/passwords, installing keylogger or just rm -rf / for fun).

thread about compromise https://github.com/faisalman/ua-parser-js/issues/536