JS calls brought in for every compile for WASM

[ranile]

When compiling for wasm, the only option is to bring in JS bindings for web APIs. However, wasm is used a for a lot more than just browsers or runtime with web APIs available, causing this library to be unusable in those cases.

One such example is https://forum.dfinity.org/t/module-imports-function-wbg-now-2e07eedfb4ac9dbe-from-wbindgen-placeholder-that-is-not-exported-by-the-runtime/22083, with me also running into the same issue.

Culprit code

jsonwebtoken/Cargo.toml

Lines 30 to 35 in 5cd1887

	[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
	ring = { version = "0.17.4", features = ["std"] }
	[target.'cfg(target_arch = "wasm32")'.dependencies]
	js-sys = "0.3"
	ring = { version = "0.17.4", features = ["std", "wasm32_unknown_unknown_js"] }

Solution

Give option to opt out of JS calls on wasm targets. One way to do that is to move JS calls behind a feature flag, similar to the ring crate that is enabled here. Note that wasm32-unknown-unknown target is not enough to assume that JS API will be available, as is the case for the platform of the forum post linked above