Added integer parsing functions in base/string_to_number.h

webrtc/base/string_to_number_unittest.cc

+/*
+ *  Copyright 2017 The WebRTC 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 in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include "webrtc/base/string_to_number.h"
+
+#include <string>
+#include <type_traits>
+#include <limits>
+
+#include "webrtc/base/gunit.h"
+
+namespace rtc {
+
+namespace {
+// clang-format off
+using IntegerTypes =
+    ::testing::Types<signed char, unsigned char,       // NOLINT(runtime/int)

[kwiberg-webrtc, 2017/04/05 09:01:15]

And char! It isn't the same as either signed or unsigned char...

[ossu, 2017/04/05 10:15:36]

Really? Well I'll be darned...

+                     short,       unsigned short,      // NOLINT(runtime/int)
+                     int,         unsigned int,        // NOLINT(runtime/int)
+                     long,        unsigned long,       // NOLINT(runtime/int)
+                     long long,   unsigned long long,  // NOLINT(runtime/int)
+                     int8_t,      uint8_t,
+                     int16_t,     uint16_t,
+                     int32_t,     uint32_t,
+                     int64_t,     uint64_t>;
+// clang-format on
+
+template <typename T>
+class BasicNumberTest : public ::testing::Test {};
+
+TYPED_TEST_CASE_P(BasicNumberTest);
+
+TYPED_TEST_P(BasicNumberTest, TestValidNumbers) {
+  using T = TypeParam;
+  constexpr T min_value = std::numeric_limits<T>::lowest();
+  constexpr T max_value = std::numeric_limits<T>::max();
+  const std::string min_string = std::to_string(min_value);
+  const std::string max_string = std::to_string(max_value);
+  EXPECT_EQ(min_value, StringToNumber<T>(min_string));
+  EXPECT_EQ(min_value, StringToNumber<T>(min_string.c_str()));
+  EXPECT_EQ(max_value, StringToNumber<T>(max_string));
+  EXPECT_EQ(max_value, StringToNumber<T>(max_string.c_str()));
+  EXPECT_EQ(0, StringToNumber<T>("0"));
+  EXPECT_EQ(0, StringToNumber<T>("-0"));
+  EXPECT_EQ(0, StringToNumber<T>(std::string("-0000000000000")));
+}
+
+TYPED_TEST_P(BasicNumberTest, TestInvalidNumbers) {
+  using T = TypeParam;
+  // Value ranges aren't strictly enforced in this test, since that would either
+  // require doctoring specific strings for each data type, which is a hassle
+  // across platforms, or to be able to do addition of values larger than the
+  // largest type, which is another hassle.
+  constexpr T min_value = std::numeric_limits<T>::lowest();
+  constexpr T max_value = std::numeric_limits<T>::max();
+  // If the type supports negative values, make the large negative value
+  // approximately ten times larger. If the type is unsigned, just use -2.
+  const std::string too_low_string =
+      (min_value == 0) ? "-2" : (std::to_string(min_value) + "1");
+  // Make the large value approximately ten times larger than the maximum.
+  const std::string too_large_string = std::to_string(max_value) + "1";
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(too_low_string));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(too_low_string.c_str()));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(too_large_string));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(too_large_string.c_str()));
+}
+
+TYPED_TEST_P(BasicNumberTest, TestInvalidInputs) {
+  using T = TypeParam;
+  const char kInvalidCharArray[] = "Invalid string containing 47";
+  const char kPlusMinusCharArray[] = "+-100";
+  const char kNumberFollowedByCruft[] = "640x480";
+  const rtc::Optional<T> kEmptyOptional;

[kwiberg-webrtc, 2017/04/05 09:01:15]

Unused.

[ossu, 2017/04/05 10:15:36]

Acknowledged.

+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(kInvalidCharArray));
+  EXPECT_EQ(rtc::Optional<T>(),
+            StringToNumber<T>(std::string(kInvalidCharArray)));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(kPlusMinusCharArray));
+  EXPECT_EQ(rtc::Optional<T>(),
+            StringToNumber<T>(std::string(kPlusMinusCharArray)));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(kNumberFollowedByCruft));
+  EXPECT_EQ(rtc::Optional<T>(),
+            StringToNumber<T>(std::string(kNumberFollowedByCruft)));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(" 5"));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(" - 5"));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>("- 5"));
+  EXPECT_EQ(rtc::Optional<T>(), StringToNumber<T>(" -5"));

[kwiberg-webrtc, 2017/04/05 09:01:15]

What happens if we try to parse a number followed by space, e.g. "5 "?

[ossu, 2017/04/05 10:15:36]

I can add a test for that if you want. Should be the same as a number followed
by any other character: failure.

[kwiberg-webrtc, 2017/04/05 10:55:38]

Good. But I figured a reasonable conversion function might treat spaces
differently from other junk, which is why a test might make sense.

+}
+
+REGISTER_TYPED_TEST_CASE_P(BasicNumberTest,
+                           TestValidNumbers,
+                           TestInvalidNumbers,
+                           TestInvalidInputs);
+
+}  // namespace
+
+INSTANTIATE_TYPED_TEST_CASE_P(StringToNumberTest_Integers,
+                              BasicNumberTest,
+                              IntegerTypes);
+
+TEST(StringToNumberTest, TestSpecificValues) {
+  EXPECT_EQ(rtc::Optional<uint8_t>(), StringToNumber<uint8_t>("256"));
+  EXPECT_EQ(rtc::Optional<uint8_t>(), StringToNumber<uint8_t>("-256"));
+  EXPECT_EQ(rtc::Optional<int8_t>(), StringToNumber<int8_t>("256"));
+  EXPECT_EQ(rtc::Optional<int8_t>(), StringToNumber<int8_t>("-256"));
+}
+
+}  // namespace rtc