psc-docs is using Show instance for errors

[hdgarrood]

For example, on current slamdata master (I guess they're using an older compiler?)

$ pulp docs
* Generating documentation in /home/harry/documents/code/slamdata
psc-docs: error: unknown module "ModuleName [ProperName {runProperName = "View"},ProperName {runProperName = "File"},ProperName {runProperName = "Modal"},ProperName {runProperName = "Mount"}]"
* ERROR: Subcommand terminated with error code 1

[garyb]

I guess they're using an older compiler?

Yeah, master is stuck on psc 0.7.2. Main development is in the new-halogen branch currently.

[paf31]

So is this a bug in master?

[hdgarrood]

Sorry, yes, my point was that it would probably be better for psc-docs to not use the Show ModuleName instance when reporting errors.

[hdgarrood]

I can't reproduce this now. Maybe it's been fixed, somehow.

I think the problem must have been somewhere inside Language.PureScript (i.e. the library) rather than inside the code specific psc-docs, given that the "unknown module" part is displayed in a human-friendly way, it's just the actual module name that's using Show.

If I try to run pulp docs without first running bower install, in order to purposefully trigger an unknown module error, I do now get a properly formatted error:

Error found:
at /home/harry/documents/code/slamdata/src/View/Modal/Common.purs line 21, column 1 - line 23, column 1

  Unknown module Control.Plus


See https://github.com/purescript/purescript/wiki/Error-Code-UnknownModule for more information,
or to contribute content related to this error.

So I'm going to close this.

[hdgarrood]

Silly me, the error occurs when you pass something to --docgen that doesn't exist.

Better repro steps:

$ pulp init
$ psc-docs 'bower_components/*/src/**/*.purs' 'src/**/*.purs' --docgen LOL
psc-docs: error: unknown module "ModuleName [ProperName {runProperName = "LOL"}]"

The culprit is here:

purescript/psc-docs/Main.hs

Lines 99 to 107 in 896bbcd

	guardMissing [] = return ()
	guardMissing [mn] = do
	hPutStrLn stderr ("psc-docs: error: unknown module \"" ++ show mn ++ "\"")
	exitFailure
	guardMissing mns = do
	hPutStrLn stderr "psc-docs: error: unknown modules:"
	forM_ mns $ \mn ->
	hPutStrLn stderr (" * " ++ show mn)
	exitFailure