Fix dash-generate-components for julia on case-insensitive filesystems

[etpinard]

The problematic scenario occurs when

• the case-lowered component name equals the module name
• the --prefix option is left empty ''

See example: https://github.com/etpinard/dash-textarea-autocomplete/tree/main/src

Fixes etpinard/dash-textarea-autocomplete#7

---

The commit below prepends comp_ in jl component file names. There are other possible solutions to this problem, but I thought this one was the least-invasive. Let me know!

Contributor Checklist

• I have run the tests locally and they passed. (refer to testing section in contributing)
• I have added tests, or extended existing tests, to cover any new features or bugs fixed in this PR

optionals

• I have added entry in the CHANGELOG.md
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[alexcjohnson]

Nice catch @etpinard 🍻 I wonder though if we can scope this to just the problematic case, ie a component whose name (prefixed or not) matches the module name?

Although to play devil's advocate, in principle you could also imagine someone making a module MyThing with components named MyThing and comp_MyThing or naming the package comp_MyThing with components MyThing and comp_MyThing 😈 Perhaps the most bulletproof solution would be not a filename prefix but a subdirectory to put all the generated components into, like jl/mything.jl? That would also be slightly nicer for devs working on the JS side, to not have as many .jl files to look past. Just have to be sure this would still work in case the user makes their own src/jl/ dir and puts JS files into it.

cc @waralex

[etpinard]

Perhaps the most bulletproof solution would be not a filename prefix but a subdirectory to put all the generated components into, like jl/mything.jl?

Yep, that's a nice idea. Looking forward to hearing what @waralex has to say here. I'll make the changes accordingly once you have reach a consensus. Cheers!

[waralex]

Perhaps the most bulletproof solution would be not a filename prefix but a subdirectory to put all the generated components into, like jl/mything.jl?

Yep, that's a nice idea. Looking forward to hearing what @waralex has to say here. I'll make the changes accordingly once you have reach a consensus. Cheers!

Yes, placing files with components in a subdirectory looks like the most reasonable solution.

[etpinard]

Perhaps the most bulletproof solution would be not a filename prefix but a subdirectory to put all the generated components into, like jl/mything.jl?

Attempted in 90dfd9f

I believe this commit makes this block

dash/dash/development/_jl_components_generation.py

Lines 515 to 518 in e8ac949

	# the Julia source directory for the package won't exist on first call
	# create the Julia directory if it is missing
	if not os.path.exists("src"):
	os.makedirs("src")

obsolete. Alternatively, we could move the os.makedirs("src/jl") statement into generate_module, but then we would need to patch generate_components to make src/jl/ available for generate_struct_file which is currently called before generate_module.

Just have to be sure this would still work in case the user makes their own src/jl/ dir and puts JS files into it.

I tested two cases:

• case with no src/jl/ using dash-textarea-autocomplete#v1.0.0
• case with a js file in src/jl/ imported into the component using dash-textarea-autocomplete#jl-comp-subdir

with:

. venv/bin/activate
pip install -r requirements.txt 
pip install ../../dash
npm run build
julia --project -e 'import Pkg; Pkg.add("DashHtmlComponents")'
julia --project usage.jl

where the build script got generated from dash-component-boilerplate.

[alexcjohnson]

Agreed that we should be able to 🔪 os.makedirs("src") - then this looks good! 💃