1 files changed, 92 insertions, 0 deletions
diff --git a/js/src/tests/non262/expressions/optional-chain-first-expression.js b/js/src/tests/non262/expressions/optional-chain-first-expression.js
new file mode 100644
index 0000000000..89912aec4a
--- /dev/null
+++ b/js/src/tests/non262/expressions/optional-chain-first-expression.js
@@ -0,0 +1,92 @@
+// Verify bytecode emitter accepts all valid optional chain first expressions.
+
+const expressions = [
+  // https://tc39.es/ecma262/#sec-primary-expression
+  "this",
+  "ident",
+  "null",
+  "true",
+  "false",
+  "123",
+  "123n",
+  "'str'",
+  "[]",
+  "{}",
+  "function(){}",
+  "class{}",
+  "function*(){}",
+  "async function(){}",
+  "async function*(){}",
+  "/a/",
+  "`str`",
+  "(a + b)",
+
+  // https://tc39.es/ecma262/#sec-left-hand-side-expressions
+  "a[b]",
+  "a.b",
+  "a``",
+  "super[a]",
+  "super.a",
+  "new.target",
+  "import.meta",
+  "new C()",
+  "new C",
+  "f()",
+  "super()",
+  "a?.b",
+  "a?.[b]",
+  "a?.()",
+  "a?.``",
+];
+
+function tryParse(s, f = Function) {
+  try { f(s); } catch {}
+}
+
+function tryRun(s, f = Function) {
+  try { f(s)(); } catch {}
+}
+
+for (let expr of expressions) {
+  // Evaluate in an expression context.
+  tryRun(`void (${expr}?.());`);
+  tryRun(`void (${expr}?.p());`);
+
+  // Also try parenthesized.
+  tryRun(`void ((${expr})?.());`);
+  tryRun(`void ((${expr})?.p());`);
+}
+
+function inClassConstructor(s) {
+  return `class C { constructor() { ${s} } }`;
+}
+
+for (let expr of ["super[a]", "super.a", "super()"]) {
+  // Evaluate in an expression context.
+  tryRun(inClassConstructor(`void (${expr}?.());`));
+  tryRun(inClassConstructor(`void (${expr}?.p());`));
+
+  // Also try parenthesized.
+  tryRun(inClassConstructor(`void ((${expr})?.());`));
+  tryRun(inClassConstructor(`void ((${expr})?.p());`));
+}
+
+if (typeof parseModule === "function") {
+  const expressions = [
+    "import.meta",
+    "import('')",
+  ];
+
+  for (let expr of expressions) {
+    // Evaluate in an expression context.
+    tryParse(`void (${expr}?.());`, parseModule);
+    tryParse(`void (${expr}?.p());`, parseModule);
+
+    // Also try parenthesized.
+    tryParse(`void ((${expr})?.());`, parseModule);
+    tryParse(`void ((${expr})?.p());`, parseModule);
+  }
+}
+
+if (typeof reportCompare === "function")
+  reportCompare(true, true);