Fable: filename like "[id].fs" created with different path

[Neftedollar]

Description

Hello!
I'm trying to use fable for next js
I'm using fable-splitter and fable-compiler packages.
There is a part of my App.fsproj

    <Compile Include="pages/post/[id].fs" />
    <Compile Include="pages/about.fs" />

package.json

{
  "scripts": {
     "fableBuild": "fable-splitter App.fsproj --allFiles -o ./"
  }
}

starting npm run fableBuild
output part:

fable: Compiled pages/about.fs
fable: Compiled pages/post/[id].fs

about.js created near the about.fs ./pages/about.js
And [id].js created with the path ./post/[id].js but expected ./pages/post/[id].js

Why I need filenames like this

Repro code

https://github.com/Neftedollar/Nextjs-Fable-simple-app/tree/repro

Related information

• Fable version: 2.4.9
• Fable-splitter version: 2.1.11
• Operating system: Mac OS X 10.15.1 (19B88)

[alfonsogarciacaro]

Hmm, probably the file name is not important here. This is just because fable-splitter is just flattening the folder structure so it doesn't reflect exactly the hierarchy of the original files. We did this originally to avoid path conflicts when compiling files coming from different hierarchies.

@ncave I think you mentioned once that you had solved this problem for fable-compiler-js. Would it be possible to port the solution to fable-splitter?

[ncave]

@alfonsogarciacaro It should be possible, it's all this calling that.

We can easily add support in fable-compiler-js for PackageReference elements in projects (e.g. to resolve the Fable.React dependency, etc.). We can either consume the obj/project.assets.json created by dotnet restore, or (assuming package's already been restored), do an educated guess at the nuget path to it:

• Binary at: ~/.nuget/packages/Fable.React/5.3.5/lib/netstandard2.0/Fable.React.dll, and the source code for it at ~/.nuget/packages/Fable.React/5.3.5/fable.

This requires the exact version to be specified in the reference (technically even wildcards can be supported, at the cost of adding complexity).

Of course, other package managers can be supported too, if we find a good mechanism to define that in the project file (but I'm not trying to reopen the package manager flame wars, so fnugget about it).

[Neftedollar]

So, can I help somehow?
@alfonsogarciacaro @ncave

[alfonsogarciacaro]

It'd be great if you could send a PR ti fix this @Neftedollar. This is the code in fable-splitter that decides the output path: https://github.com/fable-compiler/Fable/blob/bd3b30ab72966ea69ba7a45694bcc1340d42c2e7/src/fable-splitter/src/index.ts#L118-L141

You can keep the folder structure by doing something like Path.relative(Path.dirname(info.entry), path). The challenge would be files that are outside the .fsproj hierarchy (you can use @ncave code for example to see how to deal with files from fable library or packages, for example). I assume the current code for deduplicating file names in case of conflict should work as is.

[Neftedollar]

@alfonsogarciacaro ok, I'll take it.
Thnx

[Neftedollar]

@alfonsogarciacaro how can I build it?
I've started npm install at the root and then:

  fable-splitter git:(master) npm run build                         

> [email protected] build /Users/neftedollar/dev/fable/Fable/src/fable-splitter
> node build.js

exec /Users/neftedollar/dev/fable/Fable/node_modules/.bin/tsc 
../../node_modules/typescript/lib/lib.es2015.iterable.d.ts(41,6): error TS2300: Duplicate identifier 'IteratorResult'.
node_modules/@types/node/index.d.ts(179,11): error TS2300: Duplicate identifier 'IteratorResult'.
Error: tsc failed with code 1
    at runNpmBin (/Users/neftedollar/dev/fable/Fable/src/fable-splitter/build.js:23:15)
    at process._tickCallback (internal/process/next_tick.js:68:7)
    at Function.Module.runMain (internal/modules/cjs/loader.js:744:11)
    at startup (internal/bootstrap/node.js:285:19)
    at bootstrapNodeJSCore (internal/bootstrap/node.js:739:3)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! [email protected] build: `node build.js`
npm ERR! Exit status 1
npm ERR! 
npm ERR! Failed at the [email protected] build script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.

what I'm doing wrong?

[Neftedollar]

@ncave @alfonsogarciacaro pls help https://github.com/fable-compiler/Fable/issues/1936#issuecomment-554764073

[ncave]

@Neftedollar I'm not sure, normally building the splitter involves running npm run build splitter at the Fable root (all the build targets are in build.fsx).

[ncave]

@Neftedollar But if you're stuck, I can take a look at adding this functionality in fable-splitter.
Also, you will soon have the option to just use the fable-compiler-js instead, once #1943 is accepted.

[Neftedollar]

@ncave thnx i'll try to build it from the root. thnx

[Neftedollar]

@ncave same story = /

node_modules/typescript/lib/lib.es2015.iterable.d.ts:41:6 - error TS2300: Duplicate identifier 'IteratorResult'.

41 type IteratorResult<T, TReturn = any> = IteratorYieldResult<T> | IteratorReturnResult<TReturn>;
        ~~~~~~~~~~~~~~

  src/fable-splitter/node_modules/@types/node/index.d.ts:179:11
    179 interface IteratorResult<T> { }
                  ~~~~~~~~~~~~~~
    'IteratorResult' was also declared here.

can you build splitter now with current package-lock.json?

here https://github.com/microsoft/TypeScript/issues/32333 they said that we need just to update @type/node but nom update is not working for me (https://github.com/microsoft/TypeScript/issues/32333#issuecomment-550227709) and few days ago it comes back

[ncave]

@Neftedollar Yes, it works for me (Node.js 12.x), and in CI. Perhaps the node/npm version that you're using is different, but that's probably not it.

[Neftedollar]

@ncave so, I've asked two coworkers run npm run build splitter but they're all failed with the same error about IteratorResult.
BUT!
I've found that if I update @types/node now, it's fixed, there is new @types/node package was released.
So it's build now! I'll update package-lock.json with @types/node
TL;DR It's work thnx

[alfonsogarciacaro]

Would it be possible to check if this is still an issue when using Fable 3 instead of Fable 2 + splitter?

[Neftedollar]

@alfonsogarciacaro I'll check it this week

[Neftedollar]

@alfonsogarciacaro I've checked it!
JS files stored in the same path as fs files.

So we can close this issue.

[alfonsogarciacaro]

Awesome, thanks a lot for checking!