Repository navigation
No error on second compile for project with missing transient dependencies. #4094
Description
I was working on the SAFE.Utils repository, and ran into some weird issue when compiling and running tests.
This is my package.json:
{
"type": "module",
"scripts": {
"pretest": "dotnet fable -o bld",
"test": "mocha bld"
},
"devDependencies": {
"mocha": "^10.8.2"
}
}
on NPM run test, the compiler failed on the initial run, because Fable.SimpleJson and Fable.Remoting.Client were missing dependencies:
Started Fable compilation...
Compiled 21/21: ..\..\src\Client\SAFE.fs
Fable compilation finished in 2329ms
.\bld\fable_modules\Fable.SimpleJson.3.24.0\SimpleJson.fs(6,12): (6,18) error FSHARP: The namespace 'Import' is not defined. (code 39)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(13,30): (13,40) error FSHARP: The type 'FileReader' is not defined. (code 39)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(37,10): (37,14) error FSHARP: The type 'File' is not defined. (code 39)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(82,32): (82,35) error FSHARP: The value, constructor, namespace or type 'Dom' is not defined. (code 39)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(87,9): (87,21) error FSHARP: Lookup on object of indeterminate type based on information prior to this program point. A type annotation may be needed prior to this program point to constrain the type of the object. This may allow the lookup to be resolved. (code 72)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(89,9): (89,22) error FSHARP: Lookup on object of indeterminate type based on information prior to this program point. A type annotation may be needed prior to this program point to constrain the type of the object. This may allow the lookup to be resolved. (code 72)
.\bld\fable_modules\Fable.Remoting.Client.7.32.0\Extensions.fs(91,17): (91,20) error FSHARP: The value, constructor, namespace or type 'Dom' is not defined. (code 39)
...
But on the second run, compilation was skipped, and tests ran:
Fable 4.23.0: F# to JavaScript compiler
Minimum @fable-org/fable-library-js version (when installed from npm): 1.6.0
Thanks to the contributor! @battermann
Stand with Ukraine! https://standwithukraine.com.ua/
Parsing SAFE.Client.Tests.fsproj...
Retrieving project options from cache, in case of issues run `dotnet fable clean` or try `--noCache` option.
Project and references (21 source files) parsed in 146ms
Skipped compilation because all generated files are up-to-date!
> test
> mocha bld
This behavior is quite confusing. Should fable generate a bundle, even if compilation fails?
I recreated the issue on a separate branch for a minimal reproduction.
Activity
MangelMaxime commentedon Apr 11, 2025
Fable don't generate bundles, it generates 1 JS file per F# file.
But indeed, in theory Fable should invalidate the cache if the dependencies changed.
What do you mean by second compilation is it a full compilation by calling
dotnet fable buildtwice ? Or is it using the watch mode?Larocceau commentedon Apr 14, 2025
Right, sorry for the incorrect word usage.
The dependencies do not change, and I think that's the odd thing: You can run the fable tool twice on the same input, with a different outcome:
MangelMaxime commentedon Apr 14, 2025
Sorry, what do you mean by that?
In the first, one you mentioned:
dotnet fabledotnet fableIs that correct?
Larocceau commentedon Apr 15, 2025
No, what I'm trying to say is that:
dotnet fable- this fails because of a missing dependencyI would expect number 2 to fail as well
shayanhabibi commentedon May 9, 2025
I think I've had this type of thing happen during plugin development. Does this behaviour occur when you have tests fail? Or after trying to compile something that fable did not accept?
What I find is that these things happen when the project hasn't been restored, and the dependencies are not linked properly. Sometimes I find compiling with fable will break the links, and I'm not sure how this works; probably to do with the intermediate steps that fable takes to compile the program. If one of those steps is interrupted, or it doesn't restore properly during that process, then I won't be able to compile until I restore the project.
At this point though, most of my screen goes red on Rider, but sometimes not. It's almost always fixed by either reloading the project or restoring the project.
MangelMaxime commentedon May 9, 2025
By default Fable 4, was restoring the project as a
csprojwhich could mess up theobjfolder.We workaround that by doing a force restore against the
fsprojonce the dependencies information were captured.Which means like you hinted if the process is interrupted it could mess up something perhaps. To confirm, @Larocceau could try to use
--test:MSBuildCrackerflag to force using MSBuild directly.With Fable 5 with moved away from this behavior by using MSBuild directly.