fix(gen-rust-wasm): get rid of unused unit warning

Author: 7sDream

crates/gen-rust-wasm/src/lib.rs

@@ -1580,8 +1580,10 @@ impl Bindgen for FunctionBindgen<'_> {
                 match amt {
                     0 => {}
                     1 => {
-                        self.push_str(&operands[0]);
-                        self.push_str("\n");
+                        if &operands[0] != "()" {
+                            self.push_str(&operands[0]);
+                            self.push_str("\n");
+                        }
                     }
                     _ => {
                         self.push_str("(");

crates/gen-rust/src/lib.rs

@@ -88,8 +88,10 @@ pub trait RustGenerator {
         sig: &FnSig,
     ) -> Vec<String> {
         let params = self.print_docs_and_params(iface, func, param_mode, &sig);
-        self.push_str(" -> ");
-        self.print_ty(iface, &func.result, TypeMode::Owned);
+        if !std::matches!(func.result, Type::Unit) {
+            self.push_str(" -> ");
+            self.print_ty(iface, &func.result, TypeMode::Owned);
+        }
         params
     }