feat(build): --no-pack flag

[ashleygwilliams]

fixes #691

adds a flag --no-pack which will skip 3 steps:

• does not copy readme
• does not copy licenses
• does not generate package.json

[ashleygwilliams]

assuming folks approve this i'll write docs for it, and then should be ready to merge

[alexcrichton]

The implementation here all looks good to me, although I might bikeshed a bit on the name. Perhaps something like --no-package-json or --no-npm-manifest or something like that? I feel like this is largely centered around the "don't do the extra steps necessary to create a package.json" part of things.

Also as a future-compatible note, this will probably want to generate a hard error if a Rust crate depends on an NPM package (e.g. when the npm dependencies implementation lands here if that is combined with --no-pack we'd want to give a first-class "this project isn't compatible with that" error)

[ashleygwilliams]

@alexcrichton yeah i thought about a manifest related type name, i'm happy to do that

if i am understanding the ask, i actually imagine the end user would want a package.json... it'd be necessary. we could still skip the cargo.toml serialization and the readme and license steps.. this convo might be best on the npm feature tracking issue tho

[ashleygwilliams]

tho.. if we would eventually with npm feature support make a packagejson for this no pack flag... that makes the name more confusing.

[ashleygwilliams]

i am waiting to sync up with @Pauan but i think we should probably just close this. when considered with the npm feature, this feature does not really make sense.

• copying readme + licenses: doesn't block and doesn't happen if they aren't there. --quiet can silence the warnings
• serializing the cargo.toml: should not be expensive, if we are already making a partial package.json because the package depends on an npm package it feels weird to make a feature that just copies the wasm-bindgen one over and not just do the whole thing. if it is expensive, the feature request is perf related.. not a feature request.

[fitzgen]

+1 for --no-package-json

[fitzgen]

Code looks good to me; will let the naming and npm deps play out.

[daxpedda]

Tried and it works. I would like to suggest skipping .gitignore too.
Additionally generating TS could be disabled by default when passing --no-pack in my opinion, maybe additionally check for --target web to do that.

I can do the rebase to if it helps @ashleygwilliams.

Code looks good to me; will let the naming and npm deps play out.

Is this blocked on #691 or not?

[daxpedda]

Suggested change

	fn get_process_steps(mode: InstallMode, no_pack: bool) -> Vec<(&'static str, BuildStep)> {
	fn get_process_steps(&self) -> Vec<(&'static str, BuildStep)> {

Would give it access to both without having to pass any parameters at all.

[BlackGlory]

Any progress?
I wouldn't even consider wasm-pack without this option.
In fact, it should be the default, the current wasm-pack build command makes it seem like the developers have bad taste.