Support custom section in Cargo.toml, ex. [wasm]

[barabadzhi]

💡 Feature description

Prequel: The original issue I had faced was wasm-pack not pulling keywords from Cargo.toml into generated package.json. This affects the visibility of the package in the registry. The solution so far is manual editing of package.json which is not ideal, imho.

Idea evolution: Why not to add support for a custom [wasm] (or [package.wasm]) section to Cargo.toml? This can be a set of key/value pairs to put into generated package.json. It can even help overriding same-name field from [package] specifically for wasm target.

💻 Basic example

[package]
name = "my-lib" # this name will be used on crates.io
                # package may be used as a native lib without possible confusion
[package.wasm]
name = "my-lib-wasm" # override, this name will be used on npm
keywords = ["one", "two", "three"] # original to generated package.json

What do you think?

PS: Would be happy to pick this one up 🤓

[suyoshi]

Yeah, that's a great idea. 👍

[ijc]

[package.wasm]
name = "my-lib-wasm" # override, this name will be used on npm

This bit wasn't done in #838, the keywords were just added to the [package] section. Should this issue be reopened?