1 files changed, 19 insertions, 0 deletions
diff --git a/js/src/tests/test262/annexB/built-ins/String/prototype/substr/start-negative.js b/js/src/tests/test262/annexB/built-ins/String/prototype/substr/start-negative.js
new file mode 100644
index 0000000000..de56b29e68
--- /dev/null
+++ b/js/src/tests/test262/annexB/built-ins/String/prototype/substr/start-negative.js
@@ -0,0 +1,19 @@
+// Copyright (C) 2016 the V8 project authors. All rights reserved.
+// This code is governed by the BSD license found in the LICENSE file.
+/*---
+esid: sec-string.prototype.substr
+es6id: B.2.3.1
+description: Behavior when "start" is a negative number
+info: |
+    [...]
+    6. If intStart < 0, let intStart be max(size + intStart, 0).
+---*/
+
+assert.sameValue('abc'.substr(-1), 'c');
+assert.sameValue('abc'.substr(-2), 'bc');
+assert.sameValue('abc'.substr(-3), 'abc');
+assert.sameValue('abc'.substr(-4), 'abc', 'size + intStart < 0');
+
+assert.sameValue('abc'.substr(-1.1), 'c', 'floating point rounding semantics');
+
+reportCompare(0, 0);