integrate readablestream with fetch and blob

components/script/dom/bindings/codegen/CodegenRust.py

@@ -906,6 +906,40 @@ def getJSToNativeConversionInfo(type, descriptorProvider, failureCode=None,
 
         return handleOptional(templateBody, declType, handleDefault("None"))
 
+    if type.isReadableStream():
+        assert not isEnforceRange and not isClamp
+
+        if failureCode is None:
+            unwrapFailureCode = '''throw_type_error(*cx, "This object is not \
+                    an instance of ReadableStream.");\n'''
+        else:
+            unwrapFailureCode = failureCode
+
+        templateBody = fill(
+            """
+            {
+                use crate::realms::{AlreadyInRealm, InRealm};
+                let in_realm_proof = AlreadyInRealm::assert_for_cx(cx);
+                match ReadableStream::from_js(cx, $${val}.get().to_object(), InRealm::Already(&in_realm_proof)) {
+                    Ok(val) => val,
+                    Err(()) => {
+                    $*{failureCode}
+                    }
+                }
+
+            }
+            """,
+            failureCode=unwrapFailureCode + "\n",
+        )
+
+        templateBody = wrapObjectTemplate(templateBody, "None",
+                                          isDefinitelyObject, type, failureCode)
+
+        declType = CGGeneric("DomRoot<ReadableStream>")
+
+        return handleOptional(templateBody, declType,
+                              handleDefault("None"))
+
     elif type.isSpiderMonkeyInterface():
         raise TypeError("Can't handle SpiderMonkey interface arguments other than typed arrays yet")
 
@@ -4481,6 +4515,9 @@ def getUnionTypeTemplateVars(type, descriptorProvider):
     elif type.isObject():
         name = type.name
         typeName = "Heap<*mut JSObject>"
+    elif type.isReadableStream():
+        name = type.name
+        typeName = "DomRoot<ReadableStream>"
     elif is_typed_array(type):
         name = type.name
         typeName = "typedarray::Heap" + name