Feature: Option to only build front end / CSR or backend / SSR

[ActuallyHappening]

I am trying to develop a Dockerfile using cargo leptos and only need to build the server binary in the docker container. There is no need to build the front end, i.e. the .html, .css, and .wasm files inside the docker container, so I am wanting to build them on my local machine and use that build to COPY target/site set into the docker container.

But, because I build the .wasm file with --release, when I run cargo leptos build --release I build both the .wasm (what I want) and the SSR binary (what I don't need). Can we add a CLI flag / option to only build the front end? This functionality is much harder to extract, but for my docker container I have hand-crafted a cargo build --target=wasm32-unknown-unknown invocation.

Currently I can just ^C the cargo leptos build process after it has built just the front end, but I would eventually like to script this, so having an option like cargo leptos build --release --front-end-only would help

[benwis]

I'm currently rewriting cargo-leptos, and that will be a feature. In the meantime, a workaround is to call wasm-pack or wasm-bindgen directly as we recommend in the example readmes

[CorvusPrudens]

If you really want this behavior in the meantime, #318 actually implements this.

The invocation would be cargo leptos build --release --lib.

[mibmo]

I'm currently rewriting cargo-leptos, and that will be a feature. In the meantime, a workaround is to call wasm-pack or wasm-bindgen directly as we recommend in the example readmes

How should I call wasm-bindgen? I think I've almost got this working for my usecase, but I don't quite get the same result as is output in site by cargo leptos build --release. Currently I'm doing wasm-bindgen --target web --no-typescript site/pkg/web.wasm site/pkg

EDIT: aha! after much debugging and staring at the source, turns out my issue was that I was optimizing the wasm prior to packing it, which I think removed some crucial instructions. The steps I ended up with are essentially just these (but not quite, as I'm doing it with nix derivations and ipetkov/crane)

1. compile wasm: cargo build --lib --no-default-features --features hydrate --target wasm32-unknown-unknown
2. pack: wasm-bindgen --target web --no-typescript path/to/the.wasm --out-dir site/pkg
3. optimize: wasm-opt -Os site/pkg/web.js --output site/pkg/web.js
4. minify: minify site/pkg/web.js --output site/pkg/web.js
5. compile style: dart-sass --no-source-map style/main.scss site/pkg/web.css
6. copy assets: cp -r public/* site/*
7. cleanup: rm site/pkg/web_bg.wasm

I'm using minify as opposed to swc's minify, as swc's CLI isn't properly implemented yet, and I was doing this all from scripted bash.