1 files changed, 31 insertions, 0 deletions
diff --git a/devtools/client/debugger/test/mochitest/browser_dbg_parser-function-defaults.js b/devtools/client/debugger/test/mochitest/browser_dbg_parser-function-defaults.js
new file mode 100644
index 000000000..55fac4055
--- /dev/null
+++ b/devtools/client/debugger/test/mochitest/browser_dbg_parser-function-defaults.js
@@ -0,0 +1,31 @@
+/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set ft=javascript ts=2 et sw=2 tw=80: */
+/* Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Test that function default arguments are correctly processed.
+ */
+
+"use strict";
+
+function test() {
+  let { Parser, ParserHelpers, SyntaxTreeVisitor } =
+    Cu.import("resource://devtools/shared/Parser.jsm", {});
+
+  function verify(source, predicate, string) {
+    let ast = Parser.reflectionAPI.parse(source);
+    let node = SyntaxTreeVisitor.filter(ast, predicate).pop();
+    let info = ParserHelpers.getIdentifierEvalString(node);
+    is(info, string, "The identifier evaluation string is correct.");
+  }
+
+  // FunctionDeclaration
+  verify("function foo(a, b='b') {}", e => e.type == "Literal", "\"b\"");
+  // FunctionExpression
+  verify("let foo=function(a, b='b') {}", e => e.type == "Literal", "\"b\"");
+  // ArrowFunctionExpression
+  verify("let foo=(a, b='b')=> {}", e => e.type == "Literal", "\"b\"");
+
+  finish();
+}