1 files changed, 32 insertions, 0 deletions
diff --git a/deps/v8/test/mjsunit/compiler/string-from-code-point.js b/deps/v8/test/mjsunit/compiler/string-from-code-point.js
new file mode 100644
index 0000000000..165ea0c234
--- /dev/null
+++ b/deps/v8/test/mjsunit/compiler/string-from-code-point.js
@@ -0,0 +1,32 @@
+// Copyright 2018 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax --opt --noalways-opt
+
+// Test that String.fromCodePoint() properly identifies zeros.
+(function() {
+  function foo(x) {
+    return String.fromCodePoint(x);
+  }
+
+  assertEquals("\u0000", foo(0));
+  assertEquals("\u0000", foo(-0));
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals("\u0000", foo(0));
+  assertEquals("\u0000", foo(-0));
+  assertOptimized(foo);
+
+  // Now passing anything outside the valid code point
+  // range should invalidate the optimized code.
+  assertThrows(_ => foo(-1));
+  assertUnoptimized(foo);
+
+  // And TurboFan should not inline the builtin anymore
+  // from now on (aka no deoptimization loop).
+  %OptimizeFunctionOnNextCall(foo);
+  assertEquals("\u0000", foo(0));
+  assertEquals("\u0000", foo(-0));
+  assertThrows(_ => foo(-1));
+  assertOptimized(foo);
+})();