Remove Flow pragmas about sucrase HOT 7 CLOSED

Interesting, I hadn't realized that the Babel transform removes @flow comments. Seems reasonable to replicate in Sucrase. It looks like it doesn't remove $FlowFixMe, though, so I'd like to call that out of scope unless there's a good reason for it.

Is this causing problems for you? Generally the goal of Sucrase is to make the simplest change that allows the code to run in the browser or node, so in that sense it shouldn't matter what comments are left around. But I could imagine issues with some intermediate build tools assuming that a @flow directive means that it hasn't had types removed yet.

from sucrase.

@alangpierce I thought it may be an issue for packages which distributed with integrated flow definitions. However, usual setup includes .js.flow for each .js and the first one takes precendence. So if pragma is present in second, it shall be ignored (because whole file is ignored). But in that case pragmas are usually removed. For now I'm using flow-remove-types to achieve that.

I thought it would be more correct if sucrase can do it as well.

As for second point, it's just a wish/dream. Right now I'm building tool which (when working with flow annotated files) tries to remove all flow-related stuff. But it lacks sourcemaps.

from sucrase.

Got it. I think the most reasonably behavior of Sucrase is usually to do exactly what Babel does, so removing @flow pragmas seems reasonable to add and I think shouldn't be hard to implement.

Thanks for pointing out flow-remove-types. I hadn't seen that, and it definitely has lots of similarities to this project. I'll have to dig into that further when I get a chance.

For the $FlowFixMe use case, I think the right thing for now is that you could fork Sucrase and add that case. If you can convince me that it's widely useful or has small/no impact on performance or code complexity, then I'd be happy to accept it, but generally I'm trying to keep the scope of this project small.

from sucrase.

Just removing flow pragmas would be suffice for me. I'm using flow-remove-types for Flow and rollup-plugin-typescript for TS. Both are pretty mediocre in quality. I would like to use sucrase instead both of them.

Solving removing $FlowFixMe is a hard task, so I'm ok you don't want to take something so complex. I'm planning on removing $FlowFixMe (which is @flow-off in my case) in my tooling by simple and dumb regex. This would work for my specific case. If I'll invent more generic solution, I would return with it.

from sucrase.

@Rich-Harris is it possible to update rollup-plugin-sucrase with sucrase: "3"?

from sucrase.

Ah right, I've been meaning to send a PR for that since releasing 3.0. I'll see if I can get a PR ready.

from sucrase.

Just sent a PR to update the rollup plugin: rollup/rollup-plugin-sucrase#2

from sucrase.