1 files changed, 60 insertions, 0 deletions
diff --git a/js/src/tests/test262/language/statements/function/params-trailing-comma-single.js b/js/src/tests/test262/language/statements/function/params-trailing-comma-single.js
new file mode 100644
index 0000000000..cd55376ce2
--- /dev/null
+++ b/js/src/tests/test262/language/statements/function/params-trailing-comma-single.js
@@ -0,0 +1,60 @@
+// This file was procedurally generated from the following sources:
+// - src/function-forms/params-trailing-comma-single.case
+// - src/function-forms/default/func-decl.template
+/*---
+description: A trailing comma should not increase the respective length, using a single parameter (function declaration)
+esid: sec-function-definitions-runtime-semantics-instantiatefunctionobject
+flags: [generated]
+info: |
+    FunctionDeclaration :
+        function BindingIdentifier ( FormalParameters ) { FunctionBody }
+
+        [...]
+        3. Let F be FunctionCreate(Normal, FormalParameters, FunctionBody,
+           scope, strict).
+        [...]
+
+    9.2.1 [[Call]] ( thisArgument, argumentsList)
+
+    [...]
+    7. Let result be OrdinaryCallEvaluateBody(F, argumentsList).
+    [...]
+
+    9.2.1.3 OrdinaryCallEvaluateBody ( F, argumentsList )
+
+    1. Let status be FunctionDeclarationInstantiation(F, argumentsList).
+    [...]
+
+    9.2.12 FunctionDeclarationInstantiation(func, argumentsList)
+
+    [...]
+    23. Let iteratorRecord be Record {[[iterator]]:
+        CreateListIterator(argumentsList), [[done]]: false}.
+    24. If hasDuplicates is true, then
+        [...]
+    25. Else,
+        b. Let formalStatus be IteratorBindingInitialization for formals with
+           iteratorRecord and env as arguments.
+    [...]
+
+    Trailing comma in the parameters list
+
+    14.1 Function Definitions
+
+    FormalParameters[Yield, Await] : FormalParameterList[?Yield, ?Await] ,
+---*/
+
+var callCount = 0;
+// Stores a reference `ref` for case evaluation
+function ref(a,) {
+  assert.sameValue(a, 42);
+  callCount = callCount + 1;
+}
+
+ref(42, 39);
+
+assert.sameValue(callCount, 1, 'function invoked exactly once');
+
+assert.sameValue(ref.length, 1, 'length is properly set');
+
+reportCompare(0, 0);