how best to build multiple Tauri2 desktop apps from a monorepo?

[ImageDeeply]

(Not sure if this goes in Issues or Discussions ...)

I want to deliver 2 different desktop apps that share lots of code, built from same git monorepo. To start with a very practical issue: how do I generate 2 sets of icons? Right now they live in /src-tauri/icons/ but there's only 1 of those.

(We will experiment with things and share results -- but I also wanted to ask the community. FYI: our js tech stack is lightweight, e.g. no React or next.js or similar. Does use CodeMirror and thus vite. Also Brython which so far is amazing, though took some work to fit with vite.)

Maybe something like this? But how do I indicate this to various dev/build steps?

my-project/
├── Cargo.toml
├── src/
├── src-tauri/
│   ├── Cargo.toml
│   └── src/
├── app1/
│   └── icons/
└── app2/
    └── icons/

Does Rust [workspace] help?

And/or [features] e.g.

[features]
app1 = []
app2 = []
default = ["app1"]  

// and:

#[cfg(feature = "app1")]
use app1::foo;

#[cfg(feature = "app2")]
use app2::bar;

[FabianLars]

For the icons you'll probably have to use the --config flag if you only have one tauri "backend" (with multiple frontends) which i assume you already use to switch between frontendDists?

ngl i would probably do it differently than what i understand from your file tree. I'd just create 2 actual tauri apps each with their own icons folder and tauri.conf.json file (removing the src-tauri dir you have besides app1 and app2 rn). Then do the code sharing via some other shared crate. Until we support something like cargo's --manifest-path option you'll have to cd into the app you want to dev/build though for tauri's commands to work.

[ImageDeeply]

Thanks for a quick reply. "2 actual tauri apps" i.e.

app1/
├── Cargo.toml
├── src/
├── src-tauri/
│   ├── Cargo.toml
│   ├── tauri.conf.json
│   └── src/
│       └── icons/

app2/
├── Cargo.toml
├── src/
├── src-tauri/
│   ├── Cargo.toml
│   ├── tauri.conf.json
│   └── src/
│       └── icons/

That was my first attempt, as 2 repos. app2 is a clone of app1, and I run a script which updates product name, version & http port in:

	'package.json',
	'src-tauri/Cargo.toml',
	'src-tauri/tauri.conf.json',

Maybe that's better than monorepo at this point.

[FabianLars]

I mean, you can have multiple tauri apps in a cargo workspace / mono repo. The src-tauri folder also doesn't have to be named like that. You just need the taur.conf.json file to be next to the tauri app's Cargo.toml file.

[ImageDeeply]

multiple tauri apps in a cargo workspace / mono repo

But the apps are nearly identical. They only differ by settings files (and feature flags based on app name), and then icons + debug or build output. e.g. if I add a dependency, I want to add in one place not to separate Cargo.toml files.

I don't mind workarounds; just trying to figure what options exist.

src-tauri folder also doesn't have to be named like that

Fair point. I've learned enough Tauri & Rust & Cargo to get things working on my machine, but many of the details are still 'black box' magic.

In the default (I think) folder structure, target is next to src-tauri (by whatever name). So to support the debug output, the parent folder of both has to differ across my 2 apps, right? (Or I need to dig deeper into what's hardcoded vs merely 'convention' that is easy to edit.)

[FabianLars]

But the apps are nearly identical. They only differ by settings files (and feature flags based on app name), and then icons + debug or build output. e.g. if I add a dependency, I want to add in one place not to separate Cargo.toml files.

In the case the --config flag approach sounds more reasonable to me. You'll have 1 base/main tauri.conf.json and then 1 or 2 overwrite configs you specify via that flag that then gets merged into the main one (since they're merged they don't need to be complete configs, only what you want overwritten).

In the default (I think) folder structure, target is next to src-tauri (by whatever name). So to support the debug output, the parent folder of both has to differ across my 2 apps, right?

The location of the target dir rarely matters. If you opt for a Cargo workspace then it'll be in the workspace root btw.

[ImageDeeply]

1 base/main tauri.conf.json and then 1 or 2 overwrite configs you specify via that flag that then gets merged into the main one

Got it. Reference for me and thread viewers: https://v2.tauri.app/develop/configuration-files/#extending-the-configuration

Is there a similar mechanism to merge additional dependencies for Cargo.toml? (Not a big deal; a few extras won't increase build size much.)

[FabianLars]

hmm no, can't think of anything other than the --features you already mentioned.