1 files changed, 37 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/Environment-unscopables.js b/js/src/jit-test/tests/debug/Environment-unscopables.js
new file mode 100644
index 000000000..0075f5072
--- /dev/null
+++ b/js/src/jit-test/tests/debug/Environment-unscopables.js
@@ -0,0 +1,37 @@
+// An Environment for a `with` statement does not observe bindings ruled out by @@unscopables.
+
+load(libdir + "asserts.js");
+
+let g = newGlobal();
+g.eval(`
+    let x = 'global';
+    function f() {
+        let obj = {
+            x: 'obj',
+            y: 'obj',
+            [Symbol.unscopables]: {x: 1},
+        };
+        with (obj)
+            debugger;
+    }
+`);
+let dbg = Debugger(g);
+let hits = 0;
+dbg.onDebuggerStatement = function (frame) {
+    let env = frame.environment;
+
+    assertEq(env.find("x") !== env, true);
+    assertEq(env.names().indexOf("x"), -1);
+    assertEq(env.getVariable("x"), undefined);
+    assertThrowsInstanceOf(() => env.setVariable("x", 7), TypeError);
+
+    assertEq(env.find("y") === env, true);
+    assertEq(env.getVariable("y"), "obj");
+    env.setVariable("y", 8);
+
+    assertEq(frame.eval("x").return, "global");
+    assertEq(frame.eval("y").return, 8);
+    hits++;
+};
+g.f();
+assertEq(hits, 1);