support non-result return values in jsg rust

compile_flags.txt

@@ -2,17 +2,17 @@
 -stdlib=libc++
 -xc++
 -nostdinc
--Ibazel-bin/external/com_cloudflare_lol_html/_virtual_includes/lolhtml
+-Ibazel-bin/external/+_repo_rules+com_cloudflare_lol_html/_virtual_includes/lolhtml
 -Ibazel-bin/external/perfetto+/
 -Iexternal/ada-url+/
 -Iexternal/abseil-cpp+/
 -Iexternal/+http+simdutf/
--Iexternal/+nbytes+nbytes/include/
--Iexternal/codspeed/google_benchmark/include/
+-Iexternal/+http+nbytes/include/
+-Iexternal/google_benchmark++_repo_rules+codspeed/google_benchmark/include/
 -Iexternal/perfetto+/include/
 -Iexternal/perfetto+/include/perfetto/base/build_configs/bazel/
 -Iexternal/boringssl+/include
--Iexternal/+ncrypto+ncrypto/include
+-Iexternal/+http+ncrypto/include
 -isystembazel-bin/external/sqlite3+
 -Isrc
 -isystem/usr/lib/llvm-21/include/c++/v1
@@ -40,30 +40,27 @@
 -isystembazel-bin/external/+http+capnp-cpp/src/kj/compat/_virtual_includes/kj-gzip
 -isystembazel-bin/external/+http+capnp-cpp/src/kj/compat/_virtual_includes/kj-http
 -isystembazel-bin/external/+http+capnp-cpp/src/kj/compat/_virtual_includes/kj-tls
--isystembazel-bin/external/workerd-cxx/_virtual_includes/core/
--isystembazel-bin/external/workerd-cxx/kj-rs/_virtual_includes/kj-rs-lib/
--isystembazel-bin/external/+_repo_rules+v8
--isystembazel-bin/external/+_repo_rules+v8/icu
+-isystembazel-bin/external/+http+workerd-cxx/_virtual_includes/core/
+-isystembazel-bin/external/+http+workerd-cxx/kj-rs/_virtual_includes/kj-rs-lib/
+-isystemexternal/+_repo_rules2+v8/include
+-isystemexternal/+_repo_rules2+v8/include/cppgc
 -isystembazel-bin/src
 -isystemexternal/brotli+/c/include
--isystemexternal/+_repo_rules2+com_googlesource_chromium_icu/source/common
+-isystemexternal/+_repo_rules3+com_googlesource_chromium_icu/source/common
 -isystemexternal/zlib+
--isystembazel-bin/src/rust/cxx-integration/_virtual_includes/cxx-include/
--isystembazel-bin/src/rust/cxx-integration/_virtual_includes/cxx-integration@cxx
--isystembazel-bin/src/rust/cxx-integration-test/_virtual_includes/cxx-integration-test@cxx
+-isystembazel-bin/src/rust/cxx-integration/_virtual_includes/lib.rs@cxx
 -isystembazel-bin/src/rust/cxx-integration-test/_virtual_includes/lib.rs@cxx
+-isystembazel-bin/src/rust/dns/_virtual_includes/lib.rs@cxx
 -isystembazel-bin/src/rust/kj/_virtual_includes/ffi
 -isystembazel-bin/src/rust/kj/_virtual_includes/http.rs@cxx
 -isystembazel-bin/src/rust/kj/_virtual_includes/io.rs@cxx
 -isystembazel-bin/src/rust/kj/tests/_virtual_includes/lib.rs@cxx
--isystembazel-bin/src/rust/python-parser/_virtual_includes/python-parser@cxx
--isystembazel-bin/src/rust/net/_virtual_includes/net@cxx
--isystembazel-bin/src/rust/transpiler/_virtual_includes/transpiler@cxx
+-isystembazel-bin/src/rust/python-parser/_virtual_includes/lib.rs@cxx
+-isystembazel-bin/src/rust/net/_virtual_includes/lib.rs@cxx
+-isystembazel-bin/src/rust/transpiler/_virtual_includes/lib.rs@cxx
 -isystembazel-bin/src/rust/api/_virtual_includes/lib.rs@cxx
--isystembazel-bin/src/rust/jsg/_virtual_includes/bridge
 -isystembazel-bin/src/rust/jsg/_virtual_includes/ffi
 -isystembazel-bin/src/rust/jsg/_virtual_includes/lib.rs@cxx
--isystembazel-bin/src/rust/jsg/_virtual_includes/modules.rs@cxx
 -isystembazel-bin/src/rust/jsg/_virtual_includes/v8.rs@cxx
 -isystembazel-bin/src/rust/jsg-test/_virtual_includes/ffi-hdrs
 -isystembazel-bin/src/rust/jsg-test/_virtual_includes/lib.rs@cxx

src/rust/api/dns.rs

@@ -18,7 +18,13 @@ pub enum DnsParserError {
 
 impl From<DnsParserError> for jsg::Error {
     fn from(val: DnsParserError) -> Self {
-        Self::new(jsg::ExceptionType::Error, val.to_string())
+        match val {
+            DnsParserError::InvalidHexString(msg) | DnsParserError::InvalidDnsResponse(msg) => {
+                Self::new_error(&msg)
+            }
+            DnsParserError::ParseIntError(msg) => Self::new_range_error(msg.to_string()),
+            DnsParserError::Unknown => Self::new_error("Unknown dns parser error"),
+        }
     }
 }
 
@@ -136,7 +142,7 @@ impl DnsUtil {
     /// `DnsParserError::InvalidHexString`
     /// `DnsParserError::ParseIntError`
     #[jsg_method]
-    pub fn parse_caa_record(&self, record: &str) -> Result<CaaRecord, DnsParserError> {
+    pub fn parse_caa_record(&self, record: String) -> Result<CaaRecord, DnsParserError> {
         // Let's remove "\\#" and the length of data from the beginning of the record
         let data = record.split_ascii_whitespace().collect::<Vec<_>>()[2..].to_vec();
         let critical = data[0].parse::<u8>()?;
@@ -191,7 +197,7 @@ impl DnsUtil {
     /// `DnsParserError::InvalidHexString`
     /// `DnsParserError::ParseIntError`
     #[jsg_method]
-    pub fn parse_naptr_record(&self, record: &str) -> jsg::Result<NaptrRecord, DnsParserError> {
+    pub fn parse_naptr_record(&self, record: String) -> jsg::Result<NaptrRecord, DnsParserError> {
         let data = record.split_ascii_whitespace().collect::<Vec<_>>()[1..].to_vec();
 
         let order_str = data[1..3].to_vec();
@@ -262,7 +268,7 @@ mod tests {
             _state: ResourceState::default(),
         };
         let record = dns_util
-            .parse_caa_record("\\# 15 00 05 69 73 73 75 65 70 6b 69 2e 67 6f 6f 67")
+            .parse_caa_record("\\# 15 00 05 69 73 73 75 65 70 6b 69 2e 67 6f 6f 67".to_owned())
             .unwrap();
 
         assert_eq!(record.critical, 0);
@@ -277,7 +283,8 @@ mod tests {
         };
         let record = dns_util
             .parse_caa_record(
-                "\\# 21 00 09 69 73 73 75 65 77 69 6c 64 6c 65 74 73 65 6e 63 72 79 70 74",
+                "\\# 21 00 09 69 73 73 75 65 77 69 6c 64 6c 65 74 73 65 6e 63 72 79 70 74"
+                    .to_owned(),
             )
             .unwrap();
 
@@ -291,8 +298,9 @@ mod tests {
         let dns_util = DnsUtil {
             _state: ResourceState::default(),
         };
-        let result =
-            dns_util.parse_caa_record("\\# 15 00 05 69 6e 76 61 6c 69 64 70 6b 69 2e 67 6f 6f 67");
+        let result = dns_util.parse_caa_record(
+            "\\# 15 00 05 69 6e 76 61 6c 69 64 70 6b 69 2e 67 6f 6f 67".to_owned(),
+        );
 
         assert!(result.is_err());
     }
@@ -303,7 +311,7 @@ mod tests {
             _state: ResourceState::default(),
         };
         let record = dns_util
-            .parse_naptr_record("\\# 37 15 b3 08 ae 01 73 0a 6d 79 2d 73 65 72 76 69 63 65 06 72 65 67 65 78 70 0b 72 65 70 6c 61 63 65 6d 65 6e 74 00")
+            .parse_naptr_record("\\# 37 15 b3 08 ae 01 73 0a 6d 79 2d 73 65 72 76 69 63 65 06 72 65 67 65 78 70 0b 72 65 70 6c 61 63 65 6d 65 6e 74 00".to_owned())
             .unwrap();
 
         assert_eq!(record.flags, "s");

src/rust/api/lib.rs

@@ -48,17 +48,17 @@ mod tests {
     #[test]
     fn test_wrap_resource_equality() {
         let harness = Harness::new();
-        harness.run_in_context(|isolate, _ctx| unsafe {
-            let mut lock = jsg::Lock::from_isolate_ptr(isolate);
+        harness.run_in_context(|lock, _ctx| unsafe {
             let dns_util = jsg::Ref::new(DnsUtil {
                 _state: ResourceState::default(),
             });
-            let mut dns_util_template = DnsUtilTemplate::new(&mut lock);
+            let mut dns_util_template = DnsUtilTemplate::new(lock);
 
-            let lhs = jsg::wrap_resource(&mut lock, dns_util.clone(), &mut dns_util_template);
-            let rhs = jsg::wrap_resource(&mut lock, dns_util, &mut dns_util_template);
+            let lhs = jsg::wrap_resource(lock, dns_util.clone(), &mut dns_util_template);
+            let rhs = jsg::wrap_resource(lock, dns_util, &mut dns_util_template);
 
             assert_eq!(lhs, rhs);
+            Ok(())
         });
     }
 }

src/rust/jsg-macros/README.md

@@ -9,7 +9,7 @@ Generates the `jsg::Struct` and `jsg::Type` implementations for data structures.
 ```rust
 #[jsg_struct]
 pub struct CaaRecord {
-    pub critical: u8,
+    pub critical: f64,
     pub field: String,
     pub value: String,
 }
@@ -20,6 +20,35 @@ pub struct MyRecord {
 }
 ```
 
+## `#[jsg_method]`
+
+Generates FFI callback functions for JSG resource methods. The `name` parameter is optional and defaults to converting the method name from `snake_case` to `camelCase`.
+
+Parameters and return values are handled via the `jsg::Wrappable` trait. Any type implementing `Wrappable` can be used as a parameter or return value:
+
+- `Option<T>` - accepts `T` or `undefined`, rejects `null`
+- `Nullable<T>` - accepts `T`, `null`, or `undefined`
+- `NonCoercible<T>` - rejects values that would require JavaScript coercion
+
+```rust
+impl DnsUtil {
+    #[jsg_method(name = "parseCaaRecord")]
+    pub fn parse_caa_record(&self, record: String) -> Result<CaaRecord, DnsParserError> {
+        // Errors are thrown as JavaScript exceptions
+    }
+
+    #[jsg_method]
+    pub fn get_name(&self) -> String {
+        self.name.clone()
+    }
+
+    #[jsg_method]
+    pub fn reset(&self) {
+        // Void methods return undefined in JavaScript
+    }
+}
+```
+
 ## `#[jsg_resource]`
 
 Generates boilerplate for JSG resources. Applied to both struct definitions and impl blocks. Automatically implements `jsg::Type::class_name()` using the struct name, or a custom name if provided via the `name` parameter.
@@ -40,7 +69,7 @@ pub struct MyUtil {
 #[jsg_resource]
 impl DnsUtil {
     #[jsg_method]
-    pub fn parse_caa_record(&self, record: &str) -> Result<CaaRecord, DnsParserError> {
+    pub fn parse_caa_record(&self, record: String) -> Result<CaaRecord, DnsParserError> {
         // implementation
     }
 }