Can't retrieve information

[fourglobe302500]

I was trying to use femto on my fable app but it keeps on emiting this err

Failed to retrieve information about react required by Fable.React

What can I do?

[MangelMaxime]

Hello @fourglobe302500,

Which version of Fable.React are you using? Are you using NPM? PNPM? Yarn?

Can you please provide a reproduction directory?

[fourglobe302500]

Ok I just updated yarn and the problem changed to this

Unhandled exception. System.Exception: Error at: `$`
Expecting an object with a field named `data` but instead got:
{
    "value": "react@npm:18.1.0",
    "children": {
        "Version": "18.1.0",
        "Dependencies": [
            {
                "descriptor": "loose-envify@npm:^1.1.0",
                "locator": "loose-envify@npm:1.4.0"
            }
        ]
    }
}
   at Thoth.Json.Net.Decode.unsafeFromString[T](FSharpFunc`2 decoder, String value)
   at Program.getPackageVersions(NodeManager nodeManager, NpmDependency pkg) in /Users/zaid/projects/Femto/src/Program.fs:line 217
   at Program.libraries@1529-1.Invoke(NpmDependency pkg) in /Users/zaid/projects/Femto/src/Program.fs:line 1530
   at Microsoft.FSharp.Primitives.Basics.List.map[T,TResult](FSharpFunc`2 mapping, FSharpList`1 x) in D:\a\_work\1\s\src\fsharp\FSharp.Core\local.fs:line 246
   at Microsoft.FSharp.Collections.ListModule.Map[T,TResult](FSharpFunc`2 mapping, FSharpList`1 list) in D:\a\_work\1\s\src\fsharp\FSharp.Core\list.fs:line 74
   at Program.libraries@1526.Invoke(LibraryWithNpmDeps library) in /Users/zaid/projects/Femto/src/Program.fs:line 1537
   at Microsoft.FSharp.Primitives.Basics.List.map[T,TResult](FSharpFunc`2 mapping, FSharpList`1 x) in D:\a\_work\1\s\src\fsharp\FSharp.Core\local.fs:line 244
   at Program.runner(FemtoArgs args) in /Users/zaid/projects/Femto/src/Program.fs:line 1524
   at Program.main(String[] argv) in /Users/zaid/projects/Femto/src/Program.fs:line 1664

[MangelMaxime]

It seems like yarn changed its format and Femto cannot parse it.

[MangelMaxime]

Hello @fourglobe302500,

someone reported a similar issue to your first problem. Here is my answer with a solution to it.

Note it doesn't explain the error you have in your second message. Do you remember which version of yarn you used?

Because you don't have a license field in your package.json yarn generates a strange response when running yarn yarn info react versions --json.

It returns:

{"type":"warning","data":"package.json: No license field"}
{"type":"inspect","data":["0.0.0-375616788","0.0.0-00d4f95c2","0.0.0-0203b6567","0.0.0-0935a1db3","0.0.0-0c756fb-697f004","0.0.0-0c756fb-f7f79fd","0.0.0-0cf9fc10b","0.0.0-0e4135e8c","0.0.0-0eea57724","0.0.0-1022ee0ec","0.0.0-10cc40018","0.0.0-11565a207","0.0.0-11b07597e","0.0.0-1214b302e","0.0.0-12adaffef","0.0.0-132b72d7b","0.0.0-172e...}

So form now you need to add a license field to your package.json.

If your project is private you can set it to "license": "UNLICENSED" NPM docs.

They also recommend setting "private": true as an extra security.

[fourglobe302500]

@MangelMaxime the yarn version is 3.2.1 the latest at the time

[fourglobe302500]

at the current time this issue remains since my package.json does have a license

[MangelMaxime]

@fourglobe302500

Yes, the issue in your case now is that the JSON format is not supported.

Femto was written for yarn 1, so it needs to be updated to support yarn 3 format too.

This is a matter of adapting the decoder here:

https://github.com/Zaid-Ajaj/Femto/blob/f1dd05845ca07dbae8b9df58995a1fb4fa18d940/src/Program.fs#L216

Something like that

let yarn1Decoder =Decode.field "data" (Decode.list Decode.string
let yarn3Decoder = // todo
let yarnDecoder =
    Decode.oneOf [ yarn1Decoder; yarn3Decoder ]

let versions = Decode.unsafeFromString yarnDecoder  res.Result.Output

[Zaid-Ajaj]

Fixes as of Femto v0.14.0 🚀