Cargo Features

[dependencies]
bn-rs = { version = "0.2.4", default-features = false, features = ["bn-js", "ethers-js"] }
default = bn-js, ethers-js

These default features are set whenever bn-rs is added without default-features = false somewhere in the dependency tree.

bn-js default
ethers-js default

bn-rs has 3 features without comments.