Move re-initialization logic into Rust/wasm-bindgen

Cargo.toml

@@ -27,21 +27,21 @@ chrono = { version = "0.4.41", default-features = false, features = [
 futures-channel = "0.3.31"
 futures-util = { version = "0.3.31", default-features = false }
 http = "1.3"
-js-sys = { version = "0.3.90" }
+js-sys = { version = "0.3.91" }
 serde = { version = "1.0.164", features = ["derive"] }
 serde_json = "1.0.140"
 serde-wasm-bindgen = "0.6.5"
 syn = "2.0.17"
 proc-macro2 = "1.0.60"
 quote = "1.0.28"
-wasm-bindgen = { version = "0.2.113" }
-wasm-bindgen-cli-support = { version = "0.2.113" }
-wasm-bindgen-futures = { version = "0.4.63" }
-wasm-bindgen-macro-support = { version = "0.2.113" }
-wasm-bindgen-shared = { version = "0.2.113" }
-wasm-bindgen-test = { version = "0.3.63" }
+wasm-bindgen = { version = "0.2.114" }
+wasm-bindgen-cli-support = { version = "0.2.114" }
+wasm-bindgen-futures = { version = "0.4.64" }
+wasm-bindgen-macro-support = { version = "0.2.114" }
+wasm-bindgen-shared = { version = "0.2.114" }
+wasm-bindgen-test = { version = "0.3.64" }
 wasm-streams = { version = "0.5.0" }
-web-sys = { version = "0.3.90", features = [
+web-sys = { version = "0.3.91", features = [
     "AbortController",
     "AbortSignal",
     "BinaryType",
@@ -103,11 +103,11 @@ opt-level = "z"
 # These are local patches we use to test against local wasm bindgen
 # We always align on the exact stable wasm bindgen version for releases
 [patch.crates-io]
-js-sys = { version = "0.3.90", path = './wasm-bindgen/crates/js-sys' }
-wasm-bindgen = { version = "0.2.113", path = './wasm-bindgen' }
-wasm-bindgen-cli-support = { version = "0.2.113", path = "./wasm-bindgen/crates/cli-support" }
-wasm-bindgen-futures = { version = "0.4.63", path = './wasm-bindgen/crates/futures' }
-wasm-bindgen-macro-support = { version = "0.2.113", path = "./wasm-bindgen/crates/macro-support" }
-wasm-bindgen-shared = { version = "0.2.113", path = "./wasm-bindgen/crates/shared" }
-wasm-bindgen-test = { version = "0.3.63", path = "./wasm-bindgen/crates/test" }
-web-sys = { version = "0.3.90", path = './wasm-bindgen/crates/web-sys' }
+js-sys = { version = "0.3.91", path = './wasm-bindgen/crates/js-sys' }
+wasm-bindgen = { version = "0.2.114", path = './wasm-bindgen' }
+wasm-bindgen-cli-support = { version = "0.2.114", path = "./wasm-bindgen/crates/cli-support" }
+wasm-bindgen-futures = { version = "0.4.64", path = './wasm-bindgen/crates/futures' }
+wasm-bindgen-macro-support = { version = "0.2.114", path = "./wasm-bindgen/crates/macro-support" }
+wasm-bindgen-shared = { version = "0.2.114", path = "./wasm-bindgen/crates/shared" }
+wasm-bindgen-test = { version = "0.3.64", path = "./wasm-bindgen/crates/test" }
+web-sys = { version = "0.3.91", path = './wasm-bindgen/crates/web-sys' }

worker-build/src/js/shim-unwind.js

@@ -0,0 +1,19 @@
+import { WorkerEntrypoint } from "cloudflare:workers";
+import * as exports from "./index.js";
+
+Error.stackTraceLimit = 100;
+
+// Best-effort panic logging. Lost after wasm reinit since
+// wasm-bindgen calls __wbg_reset_state internally and the
+// shim has no hook to re-register.
+if (exports.setPanicHook) {
+  exports.setPanicHook(function (message) {
+    console.error("Rust panic:", message);
+  });
+}
+
+class Entrypoint extends WorkerEntrypoint {}
+
+$HANDLERS
+
+export default Entrypoint;

worker-build/src/js/shim.js

@@ -9,7 +9,7 @@ function registerPanicHook() {
     exports.setPanicHook(function (message) {
       const panicError = new Error("Rust panic: " + message);
       console.error('Critical', panicError);
-      $PANIC_CRITICAL_ERROR
+      criticalError = true;
     });
 }
 

worker-build/src/main.rs

@@ -16,6 +16,7 @@ use clap::Parser;
 const OUT_DIR: &str = "build";
 
 const SHIM_FILE: &str = include_str!("./js/shim.js");
+const SHIM_UNWIND_FILE: &str = include_str!("./js/shim-unwind.js");
 
 pub(crate) mod binary;
 mod build;
@@ -115,21 +116,20 @@ pub fn main() -> Result<()> {
     }
 
     if module_target {
-        let shim = SHIM_FILE
-            .replace("$HANDLERS", &generate_handlers(&staging_dir)?)
-            .replace(
-                "$PANIC_CRITICAL_ERROR",
-                if builder.panic_unwind {
-                    ""
-                } else {
-                    "criticalError = true;"
-                },
-            );
+        let handlers = generate_handlers(&staging_dir)?;
+        let shim = if builder.panic_unwind {
+            // In panic=unwind mode, wasm-bindgen 0.2.114+ handles reinit
+            // natively via __wbg_termination_guard / __wbg_reset_state.
+            // The shim only provides the WorkerEntrypoint adapter layer.
+            SHIM_UNWIND_FILE.replace("$HANDLERS", &handlers)
+        } else {
+            SHIM_FILE.replace("$HANDLERS", &handlers)
+        };
         let shim_path = output_path(&staging_dir, "shim.js");
         fs::write(&shim_path, shim)
             .with_context(|| format!("Failed to write {}", shim_path.display()))?;
 
-        add_export_wrappers(&staging_dir)?;
+        add_export_wrappers(&staging_dir, builder.panic_unwind)?;
 
         update_package_json(&staging_dir)?;
 
@@ -212,7 +212,7 @@ fn generate_handlers(out_dir: &Path) -> Result<String> {
 
 static SYSTEM_FNS: &[&str] = &["__wbg_reset_state", "setPanicHook"];
 
-fn add_export_wrappers(out_dir: &Path) -> Result<()> {
+fn add_export_wrappers(out_dir: &Path, panic_unwind: bool) -> Result<()> {
     let index_path = output_path(out_dir, "index.js");
     let content = fs::read_to_string(&index_path)
         .with_context(|| format!("Failed to read {}", index_path.display()))?;
@@ -230,10 +230,18 @@ fn add_export_wrappers(out_dir: &Path) -> Result<()> {
     let shim_path = output_path(out_dir, "shim.js");
     let mut output = fs::read_to_string(&shim_path)
         .with_context(|| format!("Failed to read {}", shim_path.display()))?;
-    for class_name in class_names {
-        output.push_str(&format!(
-            "export const {class_name} = new Proxy(exports.{class_name}, classProxyHooks);\n"
-        ));
+    for class_name in &class_names {
+        if panic_unwind {
+            // In panic=unwind mode, wasm-bindgen handles reinit natively.
+            // Re-export classes directly without Proxy wrapping.
+            output.push_str(&format!(
+                "export const {class_name} = exports.{class_name};\n"
+            ));
+        } else {
+            output.push_str(&format!(
+                "export const {class_name} = new Proxy(exports.{class_name}, classProxyHooks);\n"
+            ));
+        }
     }
     fs::write(&shim_path, output)
         .with_context(|| format!("Failed to write {}", shim_path.display()))?;

worker-build/src/versions.rs

@@ -7,7 +7,7 @@ macro_rules! version {
 }
 
 // Current build toolchain, always used exactly for builds, unless overridden by {}_BIN env vars
-pub(crate) static LATEST_WASM_BINDGEN_VERSION: LazyLock<semver::Version> = version!("0.2.113");
+pub(crate) static LATEST_WASM_BINDGEN_VERSION: LazyLock<semver::Version> = version!("0.2.114");
 pub(crate) static CUR_WASM_OPT_VERSION: &str = "126";
 pub(crate) static CUR_ESBUILD_VERSION: LazyLock<semver::Version> = version!("0.27.3");