1 files changed, 79 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/gc/weakRefs.js b/js/src/jit-test/tests/gc/weakRefs.js
new file mode 100644
index 0000000000..667d9cbe2b
--- /dev/null
+++ b/js/src/jit-test/tests/gc/weakRefs.js
@@ -0,0 +1,79 @@
+// https://tc39.es/proposal-weakrefs/#sec-keepduringjob
+// When the abstract operation KeepDuringJob is called with a target object
+// reference, it adds the target to an identity Set that will point strongly at
+// the target until the end of the current Job.
+//
+// https://tc39.es/proposal-weakrefs/#sec-weakref-invariants
+// When WeakRef.prototype.deref is called, the referent (if it's not already
+// dead) is kept alive so that subsequent, synchronous accesses also return the
+// object.
+
+let wr;
+{
+  let obj = {};
+  wr = new WeakRef(obj);
+  obj = null;
+}
+// obj is out of block scope now, should be GCed.
+
+gc();
+
+assertEq(undefined == wr.deref(), false);
+
+// test for target is in another zone.
+var g = newGlobal({newCompartment: true});
+var wr2 = new g.WeakRef({});
+assertEq(undefined == wr2.deref(), false);
+
+let wr3 = g.eval("new WeakRef({})");
+let wr4 = new WeakRef(evalcx('({})', newGlobal({newCompartment: true})));
+let wr5 = new g.WeakRef(evalcx('({})', newGlobal({newCompartment: true})));
+
+var that = this;
+(function(){
+  let wr6 = new g.WeakRef(newGlobal({newCompartment: true}));
+  let wr7 = new WeakRef(wr6);
+  let wr8 = new WeakRef(that);
+  wr6 = null;
+  wr7 = null;
+  wr8 = null;
+})();
+
+gc();
+
+let wr1;
+// Allocate the object in the function to prevent marked as a singleton so the
+// object won't be kept alive by IC stub.
+function allocObj() { return {}; }
+
+(function () {
+  let obj = allocObj();
+  wr1 = new WeakRef(obj);
+  obj = null;
+})();
+
+assertEq(undefined === wr1.deref(), false);
+
+gc();
+
+// See https://tc39.es/proposal-weakrefs/#sec-weakref-invariants
+// This list is reset when synchronous work is done using the
+// ClearKeptObjects abstract operation.
+//
+// TODO:
+// Bug 1603070: The shell has no way to start a new task.
+//
+// In shell, there's no window object hence there isn't a setTimeout nor event
+// handler, so we use this function to simulate that.
+// The timeout function in shell doesn't launch a new job, and it will cause
+// this test file timeout so I didn't use it here.
+function simulateEndOfJob(fn) {
+  clearKeptObjects();
+  gc();
+  fn();
+}
+
+simulateEndOfJob(() => {
+  assertEq(undefined, wr1.deref());
+});
+