(wasm) fix: remove tower as dependency for wasm32-unknown-unknown (#2510)

Author: jlizen

Cargo.toml

@@ -105,7 +105,6 @@ url = "2.4"
 bytes = "1.0"
 serde = "1.0"
 serde_urlencoded = "0.7.1"
-tower = { version = "0.5.2", default-features = false, features = ["timeout", "util"] }
 tower-service = "0.3"
 futures-core = { version = "0.3.28", default-features = false }
 futures-util = { version = "0.3.28", default-features = false }
@@ -130,6 +129,7 @@ log = "0.4.17"
 mime = "0.3.16"
 percent-encoding = "2.3"
 tokio = { version = "1.0", default-features = false, features = ["net", "time"] }
+tower = { version = "0.5.2", default-features = false, features = ["timeout", "util"] }
 pin-project-lite = "0.2.11"
 ipnet = "2.3"
 

src/error.rs

@@ -169,6 +169,7 @@ impl Error {
 /// internal equivalents.
 ///
 /// Currently only is used for `tower::timeout::error::Elapsed`.
+#[cfg(not(target_arch = "wasm32"))]
 pub(crate) fn cast_to_internal_error(error: BoxError) -> BoxError {
     if error.is::<tower::timeout::error::Elapsed>() {
         Box::new(crate::error::TimedOut) as BoxError

src/lib.rs

@@ -173,7 +173,7 @@
 //!
 //! The Client implementation automatically switches to the WASM one when the target_arch is wasm32,
 //! the usage is basically the same as the async api. Some of the features are disabled in wasm
-//! : [`tls`], [`cookie`], [`blocking`].
+//! : [`tls`], [`cookie`], [`blocking`], as well as various `ClientBuilder` methods such as `timeout()` and `connector_layer()`.
 //!
 //!
 //! ## Optional Features