1 files changed, 108 insertions, 0 deletions
diff --git a/js/src/tests/non262/expressions/trailing_comma_arrow.js b/js/src/tests/non262/expressions/trailing_comma_arrow.js
new file mode 100644
index 0000000000..f36b476ef4
--- /dev/null
+++ b/js/src/tests/non262/expressions/trailing_comma_arrow.js
@@ -0,0 +1,108 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+// Trailing comma in CoverParenthesizedExpressionAndArrowParameterList production.
+
+// 12.2 Primary Expression
+// CoverParenthesizedExpressionAndArrowParameterList[Yield]:
+//   ( Expression[In, ?Yield] )
+//   ( Expression[In, ?Yield] , )
+//   ()
+//   ( ...BindingIdentifier[?Yield] )
+//   ( Expression[In, ?Yield] , ...BindingIdentifier[?Yield] )
+
+
+function arrow(argList, parameters = "", returnExpr = "") {
+    return eval(`
+        let fun = (${argList}) => {
+            return ${returnExpr};
+        }
+        fun(${parameters});
+    `);
+}
+
+function arrowConcise(argList, parameters = "", returnExpr = "null") {
+    return eval(`
+        let fun = (${argList}) => ${returnExpr};
+        fun(${parameters});
+    `);
+}
+
+const tests = [
+    arrow,
+    arrowConcise,
+];
+
+// Ensure parameters are passed correctly.
+for (let test of tests) {
+    assertEq(test("a, ", "10", "a"), 10);
+    assertEq(test("a, b, ", "10, 20", "a + b"), 30);
+    assertEq(test("a = 30, ", "", "a"), 30);
+    assertEq(test("a = 30, b = 40, ", "", "a + b"), 70);
+
+    assertEq(test("[a], ", "[10]", "a"), 10);
+    assertEq(test("[a], [b], ", "[10], [20]", "a + b"), 30);
+    assertEq(test("[a] = [30], ", "", "a"), 30);
+    assertEq(test("[a] = [30], [b] = [40], ", "", "a + b"), 70);
+
+    assertEq(test("{a}, ", "{a: 10}", "a"), 10);
+    assertEq(test("{a}, {b}, ", "{a: 10}, {b: 20}", "a + b"), 30);
+    assertEq(test("{a} = {a: 30}, ", "", "a"), 30);
+    assertEq(test("{a} = {a: 30}, {b} = {b: 40}, ", "", "a + b"), 70);
+}
+
+// Ensure function length doesn't change.
+for (let test of tests) {
+    assertEq(test("a, ", "", "fun.length"), 1);
+    assertEq(test("a, b, ", "", "fun.length"), 2);
+
+    assertEq(test("[a], ", "[]", "fun.length"), 1);
+    assertEq(test("[a], [b], ", "[], []", "fun.length"), 2);
+
+    assertEq(test("{a}, ", "{}", "fun.length"), 1);
+    assertEq(test("{a}, {b}, ", "{}, {}", "fun.length"), 2);
+}
+
+for (let test of tests) {
+    // Trailing comma in empty parameters list.
+    assertThrowsInstanceOf(() => test(","), SyntaxError);
+
+    // Leading comma.
+    assertThrowsInstanceOf(() => test(", a"), SyntaxError);
+    assertThrowsInstanceOf(() => test(", ...a"), SyntaxError);
+
+    // Multiple trailing comma.
+    assertThrowsInstanceOf(() => test("a, , "), SyntaxError);
+    assertThrowsInstanceOf(() => test("a..., , "), SyntaxError);
+
+    // Trailing comma after rest parameter.
+    assertThrowsInstanceOf(() => test("...a, "), SyntaxError);
+    assertThrowsInstanceOf(() => test("a, ...b, "), SyntaxError);
+
+    // Elision.
+    assertThrowsInstanceOf(() => test("a, , b"), SyntaxError);
+}
+
+// Trailing comma in non-parenthesized arrow head.
+assertThrowsInstanceOf(() => eval("a, => {}"), SyntaxError);
+assertThrowsInstanceOf(() => eval("a, => null"), SyntaxError);
+
+// Parenthesized expression is not an arrow function expression.
+for (let trail of ["", ";", "\n => {}"]) {
+    assertThrowsInstanceOf(() => eval("(a,)" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(a, b,)" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(...a, )" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(a, ...b, )" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(a, , b)" + trail), SyntaxError);
+
+    assertThrowsInstanceOf(() => eval("(,)" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(, a)" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(, ...a)" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(a, , )" + trail), SyntaxError);
+    assertThrowsInstanceOf(() => eval("(...a, , )" + trail), SyntaxError);
+}
+
+
+if (typeof reportCompare === "function")
+    reportCompare(0, 0);