Update integration_test.py

Author: chrchr-github

integration_test.py

@@ -502,4 +502,17 @@ def test_define(record_property, tmpdir):  # #589
 
     assert exitcode == 0
     assert stderr == "test.cpp:1: syntax error: failed to expand 'TEST_P', Invalid ## usage when expanding 'TEST_P': Unexpected token ')'\n"
-    assert stdout == '\n'
+    assert stdout == '\n'
+
+def test_utf16_bom(tmpdir):
+    test_file = os.path.join(tmpdir, "test.cpp")
+    with open(test_file, 'w') as f:
+        f.write(b'\xFF\xFE\x00\x3B')
+
+    args = [test_file]
+
+    exitcode, stdout, stderr = simplecpp(args, cwd=tmpdir)
+
+    assert exitcode == 0
+    assert stderr == ''
+    assert stdout == '\n'