wasm-pack should check if it's the latest version and warn if not

[ashleygwilliams]

when you run build, wasm-pack should check and see what version is latest on crates.io and if the current installed version is latest. if not, it should suggest the user update.

[daubaris]

I would love to work on this one! Any tips? 😄

[daubaris]

Also a questions, should the version of wasm-pack be hard-coded for now or would it better to fetch it from crates API?

[drager]

@daubaris: Hey, I discussed this very briefly on IRC with @ashleygwilliams. One approach to this is to check the behavior of the npm client or yarn and see what they output for outdated packages. Npm outputs something like: "npm WARN ..." with a yellow background and black text. Yarn outputs something like: "warning ..." in yellow text. So maybe, the text could be something like: "warning (in yellow) ⚠️ There's a newer version of wasm-pack available, the new version is x.x.x and you're using version x.x.x".

Regarding the approach to this issue. I first had the idea of using something like hyper for this. Make a request to the crates api and fetch the latest version of the crate and then compare that to installed one. However, wasm-pack already depends on the curl crate so I think that's a better choice. So, use curl to fetch the latest version of the crate from the crates api and then compare that version with the locally installed one, then output a warning if there's a newer one available.

This is my understanding of the feature request, so anyone, please correct me if I'm wrong.

[ashleygwilliams]

closed by #409