Introduce ExpectApproxEq, a helper function that allows making assertions that certain values are e…

net/quic/test_tools/quic_test_utils.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // Common utilities for Quic tests
 
 #ifndef NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_
 #define NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_
 
 #include <stddef.h>
@@ skipping 1015 matching lines @@
     MockAlarmFactory* alarm_factory,
     QuicCryptoServerConfig* crypto_server_config,
     QuicCompressedCertsCache* compressed_certs_cache,
     PacketSavingConnection** server_connection,
     TestQuicSpdyServerSession** server_session);
 
 // Helper to generate client side stream ids, generalizes
 // kClientDataStreamId1 etc. above.
 QuicStreamId QuicClientDataStreamId(int i);
 
+// Verifies that the relative error of |actual| with respect to |expected| is
+// no more than |margin|.
+
+template <typename T>
+void ExpectApproxEq(T expected, T actual, float relative_margin) {
+  // If |relative_margin| > 1 and T is an unsigned type, the comparison will
+  // underflow.
+  ASSERT_LE(relative_margin, 1);
+  ASSERT_GE(relative_margin, 0);
+
+  T absolute_margin = expected * relative_margin;
+
+  EXPECT_GE(expected + absolute_margin, actual);
+  EXPECT_LE(expected - absolute_margin, actual);
+}
+
 }  // namespace test
 }  // namespace net
 
 #endif  // NET_QUIC_TEST_TOOLS_QUIC_TEST_UTILS_H_