1 files changed, 10 insertions, 0 deletions
diff --git a/tools/perf/pmu-events/metric_test.py b/tools/perf/pmu-events/metric_test.py
index 15315d0f716c..ced5998bd827 100644
--- a/tools/perf/pmu-events/metric_test.py
+++ b/tools/perf/pmu-events/metric_test.py
@@ -2,7 +2,9 @@
 import unittest
 from metric import Constant
 from metric import Event
+from metric import Expression
 from metric import ParsePerfJson
+from metric import RewriteMetricsInTermsOfOthers
 
 
 class TestMetricExpressions(unittest.TestCase):
@@ -153,5 +155,13 @@ class TestMetricExpressions(unittest.TestCase):
     after = '0 * SLOTS'
     self.assertEqual(ParsePerfJson(before).Simplify().ToPerfJson(), after)
 
+  def test_RewriteMetricsInTermsOfOthers(self):
+    Expression.__eq__ = lambda e1, e2: e1.Equals(e2)
+    before = [('m1', ParsePerfJson('a + b + c + d')),
+              ('m2', ParsePerfJson('a + b + c'))]
+    after = {'m1': ParsePerfJson('m2 + d')}
+    self.assertEqual(RewriteMetricsInTermsOfOthers(before), after)
+    Expression.__eq__ = None
+
 if __name__ == '__main__':
   unittest.main()