fix: remove unwraps in proto build script

Author: tarrencev

crates/proto/build.rs

@@ -1,31 +1,34 @@
+use std::io::Write;
 use std::path::PathBuf;
 
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let out_dir =
-        PathBuf::from(std::env::var("OUT_DIR").expect("OUT_DIR environment variable not set"));
-    let target = std::env::var("TARGET").expect("TARGET environment variable not set");
-    let feature_client = std::env::var("CARGO_FEATURE_CLIENT");
-    let feature_server = std::env::var("CARGO_FEATURE_SERVER");
+    let out_dir = PathBuf::from(std::env::var("OUT_DIR")?);
+    let target = std::env::var("TARGET")?;
+    let feature_client = std::env::var("CARGO_FEATURE_CLIENT").is_ok();
+    let feature_server = std::env::var("CARGO_FEATURE_SERVER").is_ok();
 
     if target.contains("wasm32") {
-        if feature_server.is_ok() {
-            panic!("feature `server` is not supported on target `{target}`");
+        if feature_server {
+            return Err(format!(
+                "feature `server` is not supported on target `{target}`"
+            )
+            .into());
         }
 
         wasm_tonic_build::configure()
             .build_server(false)
-            .build_client(feature_client.is_ok())
+            .build_client(feature_client)
             .file_descriptor_set_path(out_dir.join("world_descriptor.bin"))
             .compile_protos(&["proto/world.proto"], &["proto"])?;
     } else {
         tonic_build::configure()
-            .build_server(feature_server.is_ok())
-            .build_client(feature_client.is_ok())
+            .build_server(feature_server)
+            .build_client(feature_client)
             .file_descriptor_set_path(out_dir.join("world_descriptor.bin"))
             .compile(&["proto/world.proto"], &["proto"])?;
     }
 
-    println!("cargo:rerun-if-changed=proto");
+    std::io::stdout().write_all(b"cargo:rerun-if-changed=proto\n")?;
 
     Ok(())
 }