1 files changed, 55 insertions, 0 deletions
diff --git a/js/src/tests/non262/PrivateName/lexical-presence.js b/js/src/tests/non262/PrivateName/lexical-presence.js
new file mode 100644
index 0000000000..4ec5c310c4
--- /dev/null
+++ b/js/src/tests/non262/PrivateName/lexical-presence.js
@@ -0,0 +1,55 @@
+// |reftest| shell-option(--enable-private-fields) skip-if(!xulRuntime.shell) -- requires shell-options
+
+// Verify that private fields are enabled.
+class A {
+  #x;
+};
+
+function assertThrowsSyntaxError(str) {
+  assertThrowsInstanceOf(() => eval(str), SyntaxError);       // Direct Eval
+  assertThrowsInstanceOf(() => (1, eval)(str), SyntaxError);  // Indirect Eval
+  assertThrowsInstanceOf(() => Function(str), SyntaxError);   // Function
+}
+
+assertThrowsSyntaxError(`
+    class B {
+        g() {
+            return this.#x;
+        }
+    };
+`);
+
+assertThrowsSyntaxError(`
+with (new class A { #x; }) {
+    class B {
+      #y;
+      constructor() { return this.#x; }
+    }
+  }
+`);
+
+// Make sure we don't create a generic binding for #x.
+with(new class {
+  #x = 12;
+}) {
+  assertEq('#x' in this, false);
+}
+
+// Try to fetch a non-existing field using different
+// compilation contexts
+function assertNonExisting(fetchCode) {
+  source = `var X = class {
+    b() {
+      ${fetchCode}
+    }
+  }
+  var a = new X;
+  a.b()`
+  assertThrowsInstanceOf(() => eval(source), SyntaxError);
+}
+
+assertNonExisting(`return eval("this.#x")"`);
+assertNonExisting(`return (1,eval)("this.#x")`);
+assertNonExisting(`var f = Function("this.#x"); return f();`);
+
+if (typeof reportCompare === 'function') reportCompare(0, 0);
+\ No newline at end of file