18 files changed, 528 insertions, 3 deletions

diff --git a/ops/optimizer_tests/cow_str.expected b/ops/optimizer_tests/cow_str.expected
new file mode 100644
index 000000000..8b28965ba
--- /dev/null
+++ b/ops/optimizer_tests/cow_str.expected
@@ -0,0 +1,11 @@
+=== Optimizer Dump ===
+returns_result: false
+has_ref_opstate: false
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(Void)
+fast_parameters: [V8Value, SeqOneByteString]
+transforms: {0: Transform { kind: SeqOneByteString(Cow), index: 0 }}
+is_async: false
+fast_compatible: true
diff --git a/ops/optimizer_tests/cow_str.out b/ops/optimizer_tests/cow_str.out
new file mode 100644
index 000000000..da405f451
--- /dev/null
+++ b/ops/optimizer_tests/cow_str.out
@@ -0,0 +1,87 @@
+#[allow(non_camel_case_types)]
+///Auto-generated by `deno_ops`, i.e: `#[op]`
+///
+///Use `op_cow_str::decl()` to get an op-declaration
+///you can include in a `deno_core::Extension`.
+pub struct op_cow_str;
+#[doc(hidden)]
+impl op_cow_str {
+    pub fn name() -> &'static str {
+        stringify!(op_cow_str)
+    }
+    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
+        use deno_core::v8::MapFnTo;
+        Self::v8_func.map_fn_to()
+    }
+    pub fn decl<'scope>() -> deno_core::OpDecl {
+        deno_core::OpDecl {
+            name: Self::name(),
+            v8_fn_ptr: Self::v8_fn_ptr(),
+            enabled: true,
+            fast_fn: Some(
+                Box::new(op_cow_str_fast {
+                    _phantom: ::std::marker::PhantomData,
+                }),
+            ),
+            is_async: false,
+            is_unstable: false,
+            is_v8: false,
+            argc: 1usize,
+        }
+    }
+    #[inline]
+    #[allow(clippy::too_many_arguments)]
+    fn call(c: Cow<'_, str>) {}
+    pub fn v8_func<'scope>(
+        scope: &mut deno_core::v8::HandleScope<'scope>,
+        args: deno_core::v8::FunctionCallbackArguments,
+        mut rv: deno_core::v8::ReturnValue,
+    ) {
+        let ctx = unsafe {
+            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
+                as *const deno_core::_ops::OpCtx)
+        };
+        let arg_0 = match deno_core::v8::Local::<
+            deno_core::v8::String,
+        >::try_from(args.get(0usize as i32)) {
+            Ok(v8_string) => {
+                ::std::borrow::Cow::Owned(deno_core::serde_v8::to_utf8(v8_string, scope))
+            }
+            Err(_) => {
+                return deno_core::_ops::throw_type_error(
+                    scope,
+                    format!("Expected string at position {}", 0usize),
+                );
+            }
+        };
+        let result = Self::call(arg_0);
+        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
+        op_state.tracker.track_sync(ctx.id);
+    }
+}
+struct op_cow_str_fast {
+    _phantom: ::std::marker::PhantomData<()>,
+}
+impl<'scope> deno_core::v8::fast_api::FastFunction for op_cow_str_fast {
+    fn function(&self) -> *const ::std::ffi::c_void {
+        op_cow_str_fast_fn as *const ::std::ffi::c_void
+    }
+    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
+        use deno_core::v8::fast_api::Type::*;
+        use deno_core::v8::fast_api::CType;
+        &[V8Value, SeqOneByteString]
+    }
+    fn return_type(&self) -> deno_core::v8::fast_api::CType {
+        deno_core::v8::fast_api::CType::Void
+    }
+}
+fn op_cow_str_fast_fn<'scope>(
+    _: deno_core::v8::Local<deno_core::v8::Object>,
+    c: *const deno_core::v8::fast_api::FastApiOneByteString,
+) -> () {
+    use deno_core::v8;
+    use deno_core::_ops;
+    let c = ::std::borrow::Cow::Borrowed(unsafe { &*c }.as_str());
+    let result = op_cow_str::call(c);
+    result
+}
diff --git a/ops/optimizer_tests/cow_str.rs b/ops/optimizer_tests/cow_str.rs
new file mode 100644
index 000000000..b7214bdc7
--- /dev/null
+++ b/ops/optimizer_tests/cow_str.rs
@@ -0,0 +1,3 @@
+fn op_cow_str(c: Cow<'_, str>) {
+  // ...
+}
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.expected b/ops/optimizer_tests/op_blob_revoke_object_url.expected
index 0fae25e86..00a896433 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.expected
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.expected
@@ -1 +1,11 @@
-MustBeSingleSegment
\ No newline at end of file
+=== Optimizer Dump ===
+returns_result: true
+has_ref_opstate: true
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(Void)
+fast_parameters: [V8Value, SeqOneByteString]
+transforms: {1: Transform { kind: SeqOneByteString(Owned), index: 1 }}
+is_async: false
+fast_compatible: false
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.out b/ops/optimizer_tests/op_blob_revoke_object_url.out
index 72bc75e05..ac51c0de7 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.out
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.out
@@ -27,7 +27,7 @@ impl op_blob_revoke_object_url {
     }
     #[inline]
     #[allow(clippy::too_many_arguments)]
-    pub fn call(state: &mut deno_core::OpState, url: String) -> Result<(), AnyError> {
+    pub fn call(state: &mut OpState, url: String) -> Result<(), AnyError> {
         let url = Url::parse(&url)?;
         let blob_store = state.borrow::<BlobStore>();
         blob_store.remove_object_url(&url);
diff --git a/ops/optimizer_tests/op_blob_revoke_object_url.rs b/ops/optimizer_tests/op_blob_revoke_object_url.rs
index 8e139da06..4ef79386e 100644
--- a/ops/optimizer_tests/op_blob_revoke_object_url.rs
+++ b/ops/optimizer_tests/op_blob_revoke_object_url.rs
@@ -1,7 +1,8 @@
 pub fn op_blob_revoke_object_url(
-  state: &mut deno_core::OpState,
+  state: &mut OpState,
   url: String,
 ) -> Result<(), AnyError> {
+  // TODO(@littledivy): fast compatible https://github.com/denoland/deno/issues/17159
   let url = Url::parse(&url)?;
   let blob_store = state.borrow::<BlobStore>();
   blob_store.remove_object_url(&url);
diff --git a/ops/optimizer_tests/op_print.expected b/ops/optimizer_tests/op_print.expected
new file mode 100644
index 000000000..0390be396
--- /dev/null
+++ b/ops/optimizer_tests/op_print.expected
@@ -0,0 +1,11 @@
+=== Optimizer Dump ===
+returns_result: true
+has_ref_opstate: true
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(Void)
+fast_parameters: [V8Value, SeqOneByteString, Bool]
+transforms: {1: Transform { kind: SeqOneByteString(Ref), index: 1 }}
+is_async: false
+fast_compatible: false
diff --git a/ops/optimizer_tests/op_print.out b/ops/optimizer_tests/op_print.out
new file mode 100644
index 000000000..bafa0b9f8
--- /dev/null
+++ b/ops/optimizer_tests/op_print.out
@@ -0,0 +1,82 @@
+#[allow(non_camel_case_types)]
+///Auto-generated by `deno_ops`, i.e: `#[op]`
+///
+///Use `op_print::decl()` to get an op-declaration
+///you can include in a `deno_core::Extension`.
+pub struct op_print;
+#[doc(hidden)]
+impl op_print {
+    pub fn name() -> &'static str {
+        stringify!(op_print)
+    }
+    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
+        use deno_core::v8::MapFnTo;
+        Self::v8_func.map_fn_to()
+    }
+    pub fn decl<'scope>() -> deno_core::OpDecl {
+        deno_core::OpDecl {
+            name: Self::name(),
+            v8_fn_ptr: Self::v8_fn_ptr(),
+            enabled: true,
+            fast_fn: None,
+            is_async: false,
+            is_unstable: false,
+            is_v8: false,
+            argc: 2usize,
+        }
+    }
+    #[inline]
+    #[allow(clippy::too_many_arguments)]
+    fn call(state: &mut OpState, msg: &str, is_err: bool) -> Result<(), AnyError> {}
+    pub fn v8_func<'scope>(
+        scope: &mut deno_core::v8::HandleScope<'scope>,
+        args: deno_core::v8::FunctionCallbackArguments,
+        mut rv: deno_core::v8::ReturnValue,
+    ) {
+        let ctx = unsafe {
+            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
+                as *const deno_core::_ops::OpCtx)
+        };
+        let arg_0 = match deno_core::v8::Local::<
+            deno_core::v8::String,
+        >::try_from(args.get(0usize as i32)) {
+            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
+            Err(_) => {
+                return deno_core::_ops::throw_type_error(
+                    scope,
+                    format!("Expected string at position {}", 0usize),
+                );
+            }
+        };
+        let arg_0 = arg_0.as_ref();
+        let arg_1 = args.get(1usize as i32);
+        let arg_1 = match deno_core::serde_v8::from_v8(scope, arg_1) {
+            Ok(v) => v,
+            Err(err) => {
+                let msg = format!(
+                    "Error parsing args at position {}: {}", 1usize,
+                    deno_core::anyhow::Error::from(err)
+                );
+                return deno_core::_ops::throw_type_error(scope, msg);
+            }
+        };
+        let result = Self::call(
+            &mut std::cell::RefCell::borrow_mut(&ctx.state),
+            arg_0,
+            arg_1,
+        );
+        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
+        op_state.tracker.track_sync(ctx.id);
+        match result {
+            Ok(result) => {}
+            Err(err) => {
+                let exception = deno_core::error::to_v8_error(
+                    scope,
+                    op_state.get_error_class_fn,
+                    &err,
+                );
+                scope.throw_exception(exception);
+            }
+        };
+    }
+}
diff --git a/ops/optimizer_tests/op_print.rs b/ops/optimizer_tests/op_print.rs
new file mode 100644
index 000000000..776ee8418
--- /dev/null
+++ b/ops/optimizer_tests/op_print.rs
@@ -0,0 +1,7 @@
+fn op_print(
+  state: &mut OpState,
+  msg: &str,
+  is_err: bool,
+) -> Result<(), AnyError> {
+  // TODO(@littledivy): fast compatible https://github.com/denoland/deno/issues/17159
+}
diff --git a/ops/optimizer_tests/owned_string.expected b/ops/optimizer_tests/owned_string.expected
new file mode 100644
index 000000000..a15275412
--- /dev/null
+++ b/ops/optimizer_tests/owned_string.expected
@@ -0,0 +1,11 @@
+=== Optimizer Dump ===
+returns_result: false
+has_ref_opstate: false
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(U32)
+fast_parameters: [V8Value, SeqOneByteString]
+transforms: {0: Transform { kind: SeqOneByteString(Owned), index: 0 }}
+is_async: false
+fast_compatible: true
diff --git a/ops/optimizer_tests/owned_string.out b/ops/optimizer_tests/owned_string.out
new file mode 100644
index 000000000..4892221f8
--- /dev/null
+++ b/ops/optimizer_tests/owned_string.out
@@ -0,0 +1,99 @@
+#[allow(non_camel_case_types)]
+///Auto-generated by `deno_ops`, i.e: `#[op]`
+///
+///Use `op_string_length::decl()` to get an op-declaration
+///you can include in a `deno_core::Extension`.
+pub struct op_string_length;
+#[doc(hidden)]
+impl op_string_length {
+    pub fn name() -> &'static str {
+        stringify!(op_string_length)
+    }
+    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
+        use deno_core::v8::MapFnTo;
+        Self::v8_func.map_fn_to()
+    }
+    pub fn decl<'scope>() -> deno_core::OpDecl {
+        deno_core::OpDecl {
+            name: Self::name(),
+            v8_fn_ptr: Self::v8_fn_ptr(),
+            enabled: true,
+            fast_fn: Some(
+                Box::new(op_string_length_fast {
+                    _phantom: ::std::marker::PhantomData,
+                }),
+            ),
+            is_async: false,
+            is_unstable: false,
+            is_v8: false,
+            argc: 1usize,
+        }
+    }
+    #[inline]
+    #[allow(clippy::too_many_arguments)]
+    fn call(string: String) -> u32 {
+        string.len() as u32
+    }
+    pub fn v8_func<'scope>(
+        scope: &mut deno_core::v8::HandleScope<'scope>,
+        args: deno_core::v8::FunctionCallbackArguments,
+        mut rv: deno_core::v8::ReturnValue,
+    ) {
+        let ctx = unsafe {
+            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
+                as *const deno_core::_ops::OpCtx)
+        };
+        let arg_0 = match deno_core::v8::Local::<
+            deno_core::v8::String,
+        >::try_from(args.get(0usize as i32)) {
+            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
+            Err(_) => {
+                return deno_core::_ops::throw_type_error(
+                    scope,
+                    format!("Expected string at position {}", 0usize),
+                );
+            }
+        };
+        let result = Self::call(arg_0);
+        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
+        op_state.tracker.track_sync(ctx.id);
+        match deno_core::serde_v8::to_v8(scope, result) {
+            Ok(ret) => rv.set(ret),
+            Err(err) => {
+                deno_core::_ops::throw_type_error(
+                    scope,
+                    format!(
+                        "Error serializing return: {}",
+                        deno_core::anyhow::Error::from(err)
+                    ),
+                )
+            }
+        };
+    }
+}
+struct op_string_length_fast {
+    _phantom: ::std::marker::PhantomData<()>,
+}
+impl<'scope> deno_core::v8::fast_api::FastFunction for op_string_length_fast {
+    fn function(&self) -> *const ::std::ffi::c_void {
+        op_string_length_fast_fn as *const ::std::ffi::c_void
+    }
+    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
+        use deno_core::v8::fast_api::Type::*;
+        use deno_core::v8::fast_api::CType;
+        &[V8Value, SeqOneByteString]
+    }
+    fn return_type(&self) -> deno_core::v8::fast_api::CType {
+        deno_core::v8::fast_api::CType::Uint32
+    }
+}
+fn op_string_length_fast_fn<'scope>(
+    _: deno_core::v8::Local<deno_core::v8::Object>,
+    string: *const deno_core::v8::fast_api::FastApiOneByteString,
+) -> u32 {
+    use deno_core::v8;
+    use deno_core::_ops;
+    let string = unsafe { &*string }.as_str().to_owned();
+    let result = op_string_length::call(string);
+    result
+}
diff --git a/ops/optimizer_tests/owned_string.rs b/ops/optimizer_tests/owned_string.rs
new file mode 100644
index 000000000..102cf00fb
--- /dev/null
+++ b/ops/optimizer_tests/owned_string.rs
@@ -0,0 +1,3 @@
+fn op_string_length(string: String) -> u32 {
+  string.len() as u32
+}
diff --git a/ops/optimizer_tests/strings.expected b/ops/optimizer_tests/strings.expected
new file mode 100644
index 000000000..ead741054
--- /dev/null
+++ b/ops/optimizer_tests/strings.expected
@@ -0,0 +1,11 @@
+=== Optimizer Dump ===
+returns_result: false
+has_ref_opstate: false
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(U32)
+fast_parameters: [V8Value, SeqOneByteString]
+transforms: {0: Transform { kind: SeqOneByteString(Ref), index: 0 }}
+is_async: false
+fast_compatible: true
diff --git a/ops/optimizer_tests/strings.out b/ops/optimizer_tests/strings.out
new file mode 100644
index 000000000..41f09c4f8
--- /dev/null
+++ b/ops/optimizer_tests/strings.out
@@ -0,0 +1,100 @@
+#[allow(non_camel_case_types)]
+///Auto-generated by `deno_ops`, i.e: `#[op]`
+///
+///Use `op_string_length::decl()` to get an op-declaration
+///you can include in a `deno_core::Extension`.
+pub struct op_string_length;
+#[doc(hidden)]
+impl op_string_length {
+    pub fn name() -> &'static str {
+        stringify!(op_string_length)
+    }
+    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
+        use deno_core::v8::MapFnTo;
+        Self::v8_func.map_fn_to()
+    }
+    pub fn decl<'scope>() -> deno_core::OpDecl {
+        deno_core::OpDecl {
+            name: Self::name(),
+            v8_fn_ptr: Self::v8_fn_ptr(),
+            enabled: true,
+            fast_fn: Some(
+                Box::new(op_string_length_fast {
+                    _phantom: ::std::marker::PhantomData,
+                }),
+            ),
+            is_async: false,
+            is_unstable: false,
+            is_v8: false,
+            argc: 1usize,
+        }
+    }
+    #[inline]
+    #[allow(clippy::too_many_arguments)]
+    fn call(string: &str) -> u32 {
+        string.len() as u32
+    }
+    pub fn v8_func<'scope>(
+        scope: &mut deno_core::v8::HandleScope<'scope>,
+        args: deno_core::v8::FunctionCallbackArguments,
+        mut rv: deno_core::v8::ReturnValue,
+    ) {
+        let ctx = unsafe {
+            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
+                as *const deno_core::_ops::OpCtx)
+        };
+        let arg_0 = match deno_core::v8::Local::<
+            deno_core::v8::String,
+        >::try_from(args.get(0usize as i32)) {
+            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
+            Err(_) => {
+                return deno_core::_ops::throw_type_error(
+                    scope,
+                    format!("Expected string at position {}", 0usize),
+                );
+            }
+        };
+        let arg_0 = arg_0.as_ref();
+        let result = Self::call(arg_0);
+        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
+        op_state.tracker.track_sync(ctx.id);
+        match deno_core::serde_v8::to_v8(scope, result) {
+            Ok(ret) => rv.set(ret),
+            Err(err) => {
+                deno_core::_ops::throw_type_error(
+                    scope,
+                    format!(
+                        "Error serializing return: {}",
+                        deno_core::anyhow::Error::from(err)
+                    ),
+                )
+            }
+        };
+    }
+}
+struct op_string_length_fast {
+    _phantom: ::std::marker::PhantomData<()>,
+}
+impl<'scope> deno_core::v8::fast_api::FastFunction for op_string_length_fast {
+    fn function(&self) -> *const ::std::ffi::c_void {
+        op_string_length_fast_fn as *const ::std::ffi::c_void
+    }
+    fn args(&self) -> &'static [deno_core::v8::fast_api::Type] {
+        use deno_core::v8::fast_api::Type::*;
+        use deno_core::v8::fast_api::CType;
+        &[V8Value, SeqOneByteString]
+    }
+    fn return_type(&self) -> deno_core::v8::fast_api::CType {
+        deno_core::v8::fast_api::CType::Uint32
+    }
+}
+fn op_string_length_fast_fn<'scope>(
+    _: deno_core::v8::Local<deno_core::v8::Object>,
+    string: *const deno_core::v8::fast_api::FastApiOneByteString,
+) -> u32 {
+    use deno_core::v8;
+    use deno_core::_ops;
+    let string = unsafe { &*string }.as_str();
+    let result = op_string_length::call(string);
+    result
+}
diff --git a/ops/optimizer_tests/strings.rs b/ops/optimizer_tests/strings.rs
new file mode 100644
index 000000000..860f1e8ec
--- /dev/null
+++ b/ops/optimizer_tests/strings.rs
@@ -0,0 +1,3 @@
+fn op_string_length(string: &str) -> u32 {
+  string.len() as u32
+}
diff --git a/ops/optimizer_tests/strings_result.expected b/ops/optimizer_tests/strings_result.expected
new file mode 100644
index 000000000..68c753cab
--- /dev/null
+++ b/ops/optimizer_tests/strings_result.expected
@@ -0,0 +1,11 @@
+=== Optimizer Dump ===
+returns_result: true
+has_ref_opstate: false
+has_rc_opstate: false
+has_fast_callback_option: false
+needs_fast_callback_option: false
+fast_result: Some(U32)
+fast_parameters: [V8Value, SeqOneByteString]
+transforms: {0: Transform { kind: SeqOneByteString(Ref), index: 0 }}
+is_async: false
+fast_compatible: false
diff --git a/ops/optimizer_tests/strings_result.out b/ops/optimizer_tests/strings_result.out
new file mode 100644
index 000000000..8446a603b
--- /dev/null
+++ b/ops/optimizer_tests/strings_result.out
@@ -0,0 +1,71 @@
+#[allow(non_camel_case_types)]
+///Auto-generated by `deno_ops`, i.e: `#[op]`
+///
+///Use `op_string_length::decl()` to get an op-declaration
+///you can include in a `deno_core::Extension`.
+pub struct op_string_length;
+#[doc(hidden)]
+impl op_string_length {
+    pub fn name() -> &'static str {
+        stringify!(op_string_length)
+    }
+    pub fn v8_fn_ptr<'scope>() -> deno_core::v8::FunctionCallback {
+        use deno_core::v8::MapFnTo;
+        Self::v8_func.map_fn_to()
+    }
+    pub fn decl<'scope>() -> deno_core::OpDecl {
+        deno_core::OpDecl {
+            name: Self::name(),
+            v8_fn_ptr: Self::v8_fn_ptr(),
+            enabled: true,
+            fast_fn: None,
+            is_async: false,
+            is_unstable: false,
+            is_v8: false,
+            argc: 1usize,
+        }
+    }
+    #[inline]
+    #[allow(clippy::too_many_arguments)]
+    fn call(string: &str) -> Result<u32, AnyError> {
+        Ok(string.len() as u32)
+    }
+    pub fn v8_func<'scope>(
+        scope: &mut deno_core::v8::HandleScope<'scope>,
+        args: deno_core::v8::FunctionCallbackArguments,
+        mut rv: deno_core::v8::ReturnValue,
+    ) {
+        let ctx = unsafe {
+            &*(deno_core::v8::Local::<deno_core::v8::External>::cast(args.data()).value()
+                as *const deno_core::_ops::OpCtx)
+        };
+        let arg_0 = match deno_core::v8::Local::<
+            deno_core::v8::String,
+        >::try_from(args.get(0usize as i32)) {
+            Ok(v8_string) => deno_core::serde_v8::to_utf8(v8_string, scope),
+            Err(_) => {
+                return deno_core::_ops::throw_type_error(
+                    scope,
+                    format!("Expected string at position {}", 0usize),
+                );
+            }
+        };
+        let arg_0 = arg_0.as_ref();
+        let result = Self::call(arg_0);
+        let op_state = ::std::cell::RefCell::borrow(&*ctx.state);
+        op_state.tracker.track_sync(ctx.id);
+        match result {
+            Ok(result) => {
+                rv.set_uint32(result as u32);
+            }
+            Err(err) => {
+                let exception = deno_core::error::to_v8_error(
+                    scope,
+                    op_state.get_error_class_fn,
+                    &err,
+                );
+                scope.throw_exception(exception);
+            }
+        };
+    }
+}
diff --git a/ops/optimizer_tests/strings_result.rs b/ops/optimizer_tests/strings_result.rs
new file mode 100644
index 000000000..f89efaab1
--- /dev/null
+++ b/ops/optimizer_tests/strings_result.rs
@@ -0,0 +1,4 @@
+// https://github.com/denoland/deno/issues/16979
+fn op_string_length(string: &str) -> Result<u32, AnyError> {
+  Ok(string.len() as u32)
+}