feat: validate workspace protocol frames in browser

crates/protocol/examples/generate_typescript.rs

@@ -1,11 +1,38 @@
 #[cfg(feature = "typescript")]
 fn main() -> Result<(), Box<dyn std::error::Error>> {
-    let path = protocol::typescript::generated_typescript_path();
-    if let Some(parent) = path.parent() {
-        std::fs::create_dir_all(parent)?;
+    let check = std::env::args()
+        .skip(1)
+        .any(|argument| argument == "--check");
+    let outputs = [
+        (
+            protocol::typescript::generated_typescript_path(),
+            protocol::typescript::generated_protocol_types(),
+        ),
+        (
+            protocol::typescript::generated_runtime_validator_path(),
+            protocol::typescript::generated_protocol_validator(),
+        ),
+    ];
+
+    for (path, expected) in outputs {
+        if check {
+            let actual = std::fs::read_to_string(&path)?;
+            if actual != expected {
+                return Err(format!(
+                    "generated protocol artifact is stale: {}; run without --check",
+                    path.display()
+                )
+                .into());
+            }
+            println!("current {}", path.display());
+        } else {
+            if let Some(parent) = path.parent() {
+                std::fs::create_dir_all(parent)?;
+            }
+            std::fs::write(&path, expected)?;
+            println!("wrote {}", path.display());
+        }
     }
-    std::fs::write(&path, protocol::typescript::generated_protocol_types())?;
-    println!("wrote {}", path.display());
     Ok(())
 }