refactor(fetch): use Option<Vec<u8>> for request body handling and remove HasBody extension

Author: HiteshShonak

core/runtime/src/fetch/request.rs

@@ -25,9 +25,6 @@ pub struct RequestInit {
     signal: Option<JsObject>,
 }
 
-#[derive(Clone, Copy)]
-struct HasBody;
-
 impl RequestInit {
     /// Takes the abort signal from the options, if present.
     pub fn take_signal(&mut self) -> Option<JsObject> {
@@ -45,13 +42,15 @@ impl RequestInit {
     ) -> JsResult<HttpRequest<Vec<u8>>> {
         let mut builder = HttpRequest::builder();
         let mut is_get_or_head_method = true;
-        let mut has_inherited_body = false;
-        let mut request_body = Vec::new();
+        let mut inherited_is_get_or_head_method = true;
+        let mut inherited_body = None;
+        let mut request_body: Option<Vec<u8>> = None;
         if let Some(r) = request {
             let (parts, body) = r.into_parts();
             is_get_or_head_method = matches!(parts.method, http::Method::GET | http::Method::HEAD);
+            inherited_is_get_or_head_method = is_get_or_head_method;
             // https://fetch.spec.whatwg.org/#dom-request - "Let inputBody be input's request's body if input is a Request object; otherwise null."
-            has_inherited_body = parts.extensions.get::<HasBody>().is_some() || !body.is_empty();
+            inherited_body = Some(body);
             builder = builder
                 .method(parts.method)
                 .uri(parts.uri)
@@ -60,7 +59,6 @@ impl RequestInit {
             for (key, value) in &parts.headers {
                 builder = builder.header(key, value);
             }
-            request_body = body;
         }
 
         if let Some(headers) = self.headers.take() {
@@ -78,8 +76,16 @@ impl RequestInit {
             builder = builder.method(method.as_str());
         }
 
-        // https://fetch.spec.whatwg.org/#dom-request - "If either init["body"] exists and is non-null or inputBody is non-null, and request's method is GET or HEAD, then throw a TypeError."
-        if is_get_or_head_method && (self.body.is_some() || has_inherited_body) {
+        // Fetch Standard §5.4 Request constructor:
+        // If either init["body"] exists and is non-null or inputBody is non-null,
+        // and request's method is GET or HEAD, then throw a TypeError.
+        // https://fetch.spec.whatwg.org/#dom-request
+        if is_get_or_head_method
+            && (self.body.is_some()
+                || inherited_body
+                    .as_ref()
+                    .is_some_and(|body| !body.is_empty() || !inherited_is_get_or_head_method))
+        {
             return Err(js_error!(TypeError: "Request with GET/HEAD method cannot have body."));
         }
 
@@ -89,20 +95,19 @@ impl RequestInit {
                 let body = body.to_std_string().map_err(
                     |_| js_error!(TypeError: "Request constructor: body is not a valid string"),
                 )?;
-                request_body = body.into_bytes();
+                request_body = Some(body.into_bytes());
             } else {
                 return Err(
                     js_error!(TypeError: "Request constructor: body is not a supported type"),
                 );
             }
+        } else if let Some(body) = inherited_body {
+            request_body = Some(body);
         }
 
-        let mut request = builder
-            .body(request_body)
+        let request = builder
+            .body(request_body.unwrap_or_default())
             .map_err(|_| js_error!(Error: "Cannot construct request"))?;
-        if self.body.is_some() || has_inherited_body {
-            request.extensions_mut().insert(HasBody);
-        }
         Ok(request)
     }
 }