1 files changed, 94 insertions, 0 deletions
diff --git a/js/src/tests/non262/PrivateName/illegal-delete.js b/js/src/tests/non262/PrivateName/illegal-delete.js
new file mode 100644
index 0000000000..464b7dd685
--- /dev/null
+++ b/js/src/tests/non262/PrivateName/illegal-delete.js
@@ -0,0 +1,94 @@
+// |reftest| skip-if(!xulRuntime.shell) -- needs newGlobal()
+
+class A {
+  #x = {a: 1};
+  b = null;
+  es(s) {
+    eval(s);
+  }
+}
+
+var a = new A;
+a.b = new A;
+
+assertThrowsInstanceOf(() => a.es('delete this.#x'), SyntaxError);
+assertThrowsInstanceOf(() => a.es('delete (this.#x)'), SyntaxError);
+assertThrowsInstanceOf(() => a.es('delete this?.#x'), SyntaxError);
+assertThrowsInstanceOf(() => a.es('delete this?.b.#x'), SyntaxError);
+// Should be OK
+a.es('delete (0, this.#x.a)')
+a.es('delete this?.b.#x.a')
+
+
+// Make sure the above works in a different context, with emphasis on
+// lazy/syntax parsing.
+function eval_and_report(str) {
+  var classTest = `
+  class B {
+    #x = {a: 1};
+    b = null;
+    test() {
+      ${str};
+    }
+  }
+  var b = new B;
+  b.b = new B;
+  b.test();
+ `;
+
+  var str = `
+  function f(run) {
+    if (run) {
+      ${classTest}
+    }
+  }
+  f(run)`;
+
+
+  var throws = [];
+  // Evalutate in a new global; has the advantage that it makes successes
+  // idempotent.
+  var g = newGlobal();
+  g.run = false;
+
+  try {
+    // The idea is that this is a full parse
+    evaluate(classTest, {global: g});
+  } catch (e) {
+    throws.push(e);
+  }
+
+  try {
+    // The idea is this is a lazy parse; however, fields currently
+    // disable lazy parsing, so right now
+    evaluate(str, {global: g});
+  } catch (e) {
+    throws.push(e);
+  }
+
+  return throws;
+}
+
+function assertSyntaxError(str) {
+  var exceptions = eval_and_report(str);
+  assertEq(exceptions.length, 2);
+  for (var e of exceptions) {
+    assertEq(/SyntaxError/.test(e.name), true);
+  }
+}
+
+function assertNoSyntaxError(str) {
+  var exceptions = eval_and_report(str);
+  assertEq(exceptions.length, 0);
+}
+
+assertSyntaxError('delete this.#x');
+assertSyntaxError('delete (this.#x)');
+assertSyntaxError('delete this?.#x');
+assertSyntaxError('delete this?.b.#x');
+// Should be OK
+assertNoSyntaxError('delete (0, this.#x.a)')
+assertNoSyntaxError('delete this?.b.#x.a')
+
+
+if (typeof reportCompare === 'function') reportCompare(0, 0);