Compile JS without bundling

[Neftedollar]

Fable 1.0 beta Subj

[Pauan]

Hmm, I wonder if rollup-loader can be used to reduce the amount of boilerplate.

[alfonsogarciacaro]

Fable 1.0 is delegating many of the functions implemented (with flaws) in previous versions of Fable like watching, resolving dependencies, etc. However, it shouldn't be difficult for the community to provide alternatives to fable-loader that communicate with Fable server independently. Could you give more details of your use case and what would you like the workflow to be, @Neftedollar? If you just want to hide the webpack config file, this would be as easy as creating a JS script that calls webpack under the hood with a default configuration.

[Neftedollar]

@alfonsogarciacaro I understand. I want to use fable with meteorjs. It has it's own filepreprocessing.(pack/unpack, deploying resolve dependencies etc. without webpack) Maybe I should go another way and use Fable-Compiler inside meteorjs workflow.

Or, fireloop has is it's own workflow too.

[Neftedollar]

https://guide.meteor.com/build-tool.html

[jgrund]

@Neftedollar Fwiw I did something like this with a Jest preprocessor: https://github.com/jgrund/jest-fable-preprocessor

As long as you can take the output from the fable server and push it into Babel, you should be able to get compilation without webpack working.

[jgrund]

@Pauan +1 from me for a rollup-loader. I'm working with node on the server-side so having rollup is more advantageous for me than webpack at the moment.

[alfonsogarciacaro]

@Neftedollar In this case, probably the best thing to do would be to create a custom build plugin for Meteor, but unfortunately the documentation seems to be very thing on this. I also had a look at the Typescript Meteor package and looks quite complicated.

It wouldn't be very difficult to create a standalone version of the fable-loader similar to Fable 0.7: a command to watch and/or compile F# files. The only thing I would like to avoid because it gave many headaches is putting the compiled Js files in a different directory. This is very tricky for files (both F# and JS) outside the project folder as it is not trivial to calculate the most efficient structure and resolve references from other files.

If you don't mind having the compiled JS files side by side with the F# files, I can try to implement something :+1:

BTW, @jgrund that's very advanced bit ofJS code, it wasn't easy to follow it ;)

[Neftedollar]

@alfonsogarciacaro I've found more useful text http://docs.meteor.com/api/packagejs.html#build-plugin-api

and this one for babel https://github.com/meteor/meteor/tree/devel/packages/ecmascript

[alfonsogarciacaro]

@Neftedollar Thanks, that's more complete info indeed. Will you give it a try at writing a Meteor plugin? @jgrund just created a Rollup plugin #808 you can use for reference. I can also quickly create a node script to translate F# to JS (ES2015) without Webpack but, as commented above, the JS files would be placed next to the F# files for simplification.

[Neftedollar]

@alfonsogarciacaro I think about it. There are some doubts about meteor's ecosystem with fable. Vanilla meteor is too barren without extensions/plugins.

as commented above, the JS files would be placed next to the F# files for simplification.

It'll be enough for proof of concept fable-meteor-compiler

[alfonsogarciacaro]

Maybe this could be a task for somebody in the @fable-compiler/code-maintenance group. Here's how I would do it:

• Write a JS bootstrapper like fable-loader (with the fable-utils dependency) but that can work in a similar way as Fable 0.7.
• Implement a way so the JS bootstrapper can send an .fsproj file and receive the list of F# source files in response.
• Require compilation of each F# file to the Fable server the same way fable loader does. Then move the JS files from a baseDir (it can be the directory of the .fsproj or something specified by the user) to an outDir. We need to deal somehow with files outside the baseDir (coming from packages).
• At the moment, Fable is leaving the .fs extension in the imports. We need to add an option so we can change the extension (to .js or nothing), here as it was done in Fable 0.7.

If someone wants to volunteer, please send a WIP progress so we can continue discussion there :)

[alfonsogarciacaro]

I agree it's important for some scenarios to be able to compile JS without bundling as it was done in Fable 0.7. Someone from the @fable-compiler/code-maintenance would like to give it a try? I've outlined the necessary work above, but I can provide more guidance if needed.

[MangelMaxime]

@fable-compiler/code-maintenance I am going to work on this feature.

[ncave]

@alfonsogarciacaro Here is a WIP (#935) to kick off the discussion. It's still very raw, for now it just dumps the compiled .js directly in the outDir. Please share ideas on what the folder structure under outDir should look like.

[mike-morr]

@ncave @alfonsogarciacaro This looks pretty sweet! Putting my @fable-compiler/community team member hat on, this has been the most frequently requested feature from new people in Gitter!

[ncave]

@MangelMaxime Sorry about that, I did see your self-assignment, I just tried to contribute to the conversation to move it forward. Can we iterate / collaborate / share ideas to make it better?

[MangelMaxime]

@ncave No problem, I did have a working protytope. And was still trying to make my way around the solution.

I will try to take a look at your PR and sure we can collaborate / share idea based on it :) (Available, on the gitter or fsharp slack for easier discussion).

[Alxandr]

So I have non-bundles JS working in theory. I say in theory because I have other errors that makes me unable to test it (one of my files isn't properly compiling), but looking at the generated js files it seems it should be working. Script can be found here: https://gist.github.com/Alxandr/61e33157a3eba48436d53cc9194c269f

One cheviot: it only works if all you .fs files are in the same dir or bellow their respective .fsproj files. This could likely be fixed by simply loading all the projects first.

[ncave]

@Neftedollar You can try fable-splitter, see if it covers your use case. I'm sure it can be improved, the source is here.

[Neftedollar]

@ncave thanks! I'll try it on Saturday.

[MangelMaxime]

Should be close now ?

[Alxandr]

fable-builder also does this, but I'd argue that this is technically blocked / hacked until we can get list of files from fable server.

[ncave]

@Alxandr Traversing all the referenced paths in the Babel AST of each file gives you the relative .fs and .js file paths, see here.

[Alxandr]

@ncave yeah, I know. But it's sort of hacky not being able to ask fable for the files.