Support pre-build hook with wails dev & wails build

[SgtPooki]

Is your feature request related to a problem? Please describe.

The problem is that my team already has built our front-end assets, and we just need to include it in our desktop app (https://github.com/ipfs/ipfs-desktop).

You can see in the README of https://github.com/SgtPooki/ipfs-desktop-wails, that we don't need a front-end command to run at all, but we do need a command to run to get our prebuilt frontend (see https://github.com/SgtPooki/ipfs-desktop-wails#run-a-local-version).

Since we need to get these front-end assets between wails dev and wails generate module, we get errors unless we run an explicit command prior to running wails. I believe it would be wise for wails to offer a solution for the multitude of usecases a preBuildHook could support.

Describe the solution you'd like

wails.json already has postBuildHooks, I would like to propose preBuildHooks. Essentially an agnostic version of "frontend:*" though not necessarily a replacement.

For my issue, I would only need to run ./get-webui.sh in the preBuildHook:

wails.json

...
    "preBuildHooks": {
        "*/*": "./get-webui.sh"
    }
...

Describe alternatives you've considered

The only two solutions I could think of that allow us to fully bundle our webui in the app (obtaining via runtime is not a viable solution) are:

1. require build process to run our get-webui.sh shell script prior to running wails command
2. move .get-webui.sh to ./frontend/get-webui.sh and set "frontend:build": "bash ./get-webui.sh", in wails.json

Solution 1

This works, and is okay, but definitely not ideal, requires build cmd to be:

./get-webui.sh && wails build # or wails dev

at least on the first run.

Solution 2

This is currently what I'm using as it's the desired DX I want. See SgtPooki/ipfs-desktop-wails@fab2491

but allows us to have a single canonical wails build command:

wails build # or wails dev

Some issues with this solution that others may run into

With no ./frontend folder:

╰─ ✔ ❯ wails dev -v 2
Wails CLI v2.0.0-beta.38


Executing: go mod tidy -compat=1.17
Executing: wails generate module


ERROR:
main.go:10:12: pattern frontend: no matching files found

with existing ./frontend/.gitkeep

╰─ ✔ ❯ wails dev -v 2
Wails CLI v2.0.0-beta.38


Executing: go mod tidy -compat=1.17
Executing: wails generate module


ERROR:
main.go:10:12: pattern frontend: cannot embed directory frontend: contains no embeddable files

exit status 1

If Wails is useful to you or your company, please consider sponsoring the project:
https://github.com/sponsors/leaanthony


exit status 1

With empty ./frontend/index.html

This allows things to work, but I don't like the idea that wails could be modifying/hooking into a file that will be overwritten.

Additional context

No response

[leaanthony]

Thanks for the amazingly detailed enhancement request. Should be trivial to implement this and I can see the need.

[leaanthony]

@SgtPooki - Please check the linked PR. Is this what you had in mind?
Updated the docs here: https://0b961860.wails-website.pages.dev/docs/next/reference/project-config

[SgtPooki]

@leaanthony This is amazing. Your PR nails the interface I want. I am not the right person to speak to how you implemented it, but I believe the surface area is absolutely what I needed!

Thank you so much for throwing this together so fast. I was not expecting a response this quickly! =D