1 files changed, 45 insertions, 0 deletions
diff --git a/js/src/tests/non262/PrivateName/illegal-in-identifier-context.js b/js/src/tests/non262/PrivateName/illegal-in-identifier-context.js
new file mode 100644
index 0000000000..e7e232bf69
--- /dev/null
+++ b/js/src/tests/non262/PrivateName/illegal-in-identifier-context.js
@@ -0,0 +1,45 @@
+// |reftest| skip-if(!xulRuntime.shell)
+
+// Private names can't appear in contexts where plain identifiers are expected.
+
+// Private names as binding identifiers.
+assertThrowsInstanceOf(() => eval(`var #a;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`let #a;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`const #a = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`function #a(){}`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`function f(#a){}`), SyntaxError);
+
+// With escape sequences (leading and non-leading case).
+assertThrowsInstanceOf(() => eval(String.raw`var #\u0061;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`var #a\u0061;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`let #\u0061;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`let #a\u0061;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`const #\u0061 = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`const #a\u0061 = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`function #\u0061(){}`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`function #a\u0061(){}`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`function f(#\u0061){}`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`function f(#a\u0061){}`), SyntaxError);
+
+
+// Private names as label identifiers.
+assertThrowsInstanceOf(() => eval(`#a: ;`), SyntaxError);
+
+// With escape sequences (leading and non-leading case).
+assertThrowsInstanceOf(() => eval(String.raw`#\u0061: ;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`#a\u0061: ;`), SyntaxError);
+
+
+// Private names as identifier references.
+assertThrowsInstanceOf(() => eval(`#a = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(`typeof #a;`), SyntaxError);
+
+// With escape sequences (leading and non-leading case).
+assertThrowsInstanceOf(() => eval(String.raw`#\u0061 = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`#a\u0061 = 0;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`typeof #\u0061;`), SyntaxError);
+assertThrowsInstanceOf(() => eval(String.raw`typeof #a\u0061;`), SyntaxError);
+
+
+if (typeof reportCompare === "function")
+  reportCompare(0, 0);