Issue #2197 - Part 4: Expose structuredClone in Sandbox

Partially based on https://bugzilla.mozilla.org/show_bug.cgi?id=1734320

4 files changed, 71 insertions, 0 deletions

diff --git a/js/xpconnect/src/Sandbox.cpp b/js/xpconnect/src/Sandbox.cpp
index a34870269a..3c2145a1f7 100644
--- a/js/xpconnect/src/Sandbox.cpp
+++ b/js/xpconnect/src/Sandbox.cpp
@@ -322,6 +322,45 @@ SandboxCreateFetch(JSContext* cx, HandleObject obj)
         dom::HeadersBinding::GetConstructorObject(cx);
 }
 
+static bool SandboxStructuredClone(JSContext* cx, unsigned argc, Value* vp) {
+  CallArgs args = CallArgsFromVp(argc, vp);
+
+  if (!args.requireAtLeast(cx, "structuredClone", 1)) {
+    return false;
+  }
+
+  RootedDictionary<dom::StructuredSerializeOptions> options(cx);
+  if (!options.Init(cx, args.hasDefined(1) ? args[1] : JS::NullHandleValue,
+                    "Argument 2", false)) {
+    return false;
+  }
+
+  nsIGlobalObject* global = xpc::NativeGlobal(JS::CurrentGlobalOrNull(cx));
+  if (!global) {
+    JS_ReportErrorASCII(cx, "structuredClone: Missing global");
+    return false;
+  }
+
+  JS::Rooted<JS::Value> result(cx);
+  ErrorResult rv;
+  nsContentUtils::StructuredClone(cx, global, args[0], options, &result, rv);
+  if (rv.MaybeSetPendingException(cx)) {
+    return false;
+  }
+
+  MOZ_ASSERT_IF(result.isGCThing(),
+                !JS::GCThingIsMarkedGray(result.toGCCellPtr()));
+  args.rval().set(result);
+  return true;
+}
+
+static bool SandboxCreateStructuredClone(JSContext* cx, HandleObject obj) {
+  MOZ_ASSERT(JS_IsGlobalObject(obj));
+
+  return JS_DefineFunction(cx, obj, "structuredClone", SandboxStructuredClone,
+                           1, 0);
+}
+
 static bool
 SandboxIsProxy(JSContext* cx, unsigned argc, Value* vp)
 {
@@ -927,6 +966,8 @@ xpc::GlobalProperties::Parse(JSContext* cx, JS::HandleObject obj)
 #endif
         } else if (!strcmp(name.ptr(), "fetch")) {
             fetch = true;
+        } else if (!strcmp(name.ptr(), "structuredClone")) {
+            structuredClone = true;
         } else if (!strcmp(name.ptr(), "caches")) {
             caches = true;
         } else if (!strcmp(name.ptr(), "FileReader")) {
@@ -1002,6 +1043,9 @@ xpc::GlobalProperties::Define(JSContext* cx, JS::HandleObject obj)
     if (fetch && !SandboxCreateFetch(cx, obj))
         return false;
 
+    if (structuredClone && !SandboxCreateStructuredClone(cx, obj))
+        return false;
+
     if (caches && !dom::cache::CacheStorage::DefineCaches(cx, obj))
         return false;
 
diff --git a/js/xpconnect/src/xpcprivate.h b/js/xpconnect/src/xpcprivate.h
index 724c8db3a9..6c2711210a 100644
--- a/js/xpconnect/src/xpcprivate.h
+++ b/js/xpconnect/src/xpcprivate.h
@@ -2879,6 +2879,7 @@ struct GlobalProperties {
     bool crypto : 1;
     bool rtcIdentityProvider : 1;
     bool fetch : 1;
+    bool structuredClone : 1;
     bool caches : 1;
     bool fileReader: 1;
 private:
diff --git a/js/xpconnect/tests/unit/test_structuredClone.js b/js/xpconnect/tests/unit/test_structuredClone.js
new file mode 100644
index 0000000000..6b9b2d776a
--- /dev/null
+++ b/js/xpconnect/tests/unit/test_structuredClone.js
@@ -0,0 +1,25 @@
+function run_test() {
+  var sb = new Cu.Sandbox('http://www.example.com',
+                          { wantGlobalProperties: ["structuredClone"] });
+
+  sb.equal = equal;
+
+  sb.testing =  Components.utils.cloneInto({xyz: 123}, sb);
+  Cu.evalInSandbox(`
+    equal(structuredClone("abc"), "abc");
+
+    var obj = {a: 1};
+    obj.self = obj;
+    var clone = structuredClone(obj);
+    equal(clone.a, 1);
+    equal(clone.self, clone);
+
+    var ab = new ArrayBuffer(1);
+    clone = structuredClone(ab, {transfer: [ab]});
+    equal(clone.byteLength, 1);
+    equal(ab.byteLength, 0);
+
+    clone = structuredClone(testing);
+    equal(clone.xyz, 123);
+  `, sb);
+}
diff --git a/js/xpconnect/tests/unit/xpcshell.ini b/js/xpconnect/tests/unit/xpcshell.ini
index 12648d3ecc..b13d8d455f 100644
--- a/js/xpconnect/tests/unit/xpcshell.ini
+++ b/js/xpconnect/tests/unit/xpcshell.ini
@@ -114,6 +114,7 @@ skip-if = os == "android" # native test components aren't available on Android
 [test_css.js]
 [test_rtcIdentityProvider.js]
 [test_sandbox_atob.js]
+[test_structuredClone.js]
 [test_isProxy.js]
 [test_getObjectPrincipal.js]
 [test_sandbox_name.js]