Extend net/base/parse_number.h for parsing of negative numbers, and determining if there was overflo

net/base/parse_number_unittest.cc

Index: net/base/parse_number_unittest.cc
diff --git a/net/base/parse_number_unittest.cc b/net/base/parse_number_unittest.cc
index 79cac9f43ba211b26aa8d58d1c943154b387f911..270b7bf7e967aa93386bf3c3e2ce4f6e970c8a16 100644
--- a/net/base/parse_number_unittest.cc
+++ b/net/base/parse_number_unittest.cc
@@ -4,67 +4,315 @@
 
 #include "net/base/parse_number.h"
 
+#include <limits>
+
+#include "base/strings/string_number_conversions.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace net {
 namespace {
 
-TEST(ParseNumberTest, IntValidInputs) {
-  const struct {
-    const char* input;
-    int output;
-  } kTests[] = {
-      {"0", 0},     {"00000", 0}, {"003", 3}, {"003", 3}, {"1234566", 1234566},
-      {"987", 987}, {"010", 10},
-  };
-
-  for (const auto& test : kTests) {
-    int result;
-    ASSERT_TRUE(ParseNonNegativeDecimalInt(test.input, &result))
-        << "Failed to parse: " << test.input;
-    EXPECT_EQ(result, test.output) << "Failed to parse: " << test.input;
+// Increments the final character in a string by 1. Used as a simplistic way to
+// increment a numeric string (flawed, but good enough for use case).
+std::string IncrementLastChar(std::string value) {
+  value[value.size() - 1]++;
+  return value;
+}
+
+// These are valid inputs representing non-negative integers. Note that these
+// test inputs are re-used when constructing negative test cases, by simply
+// prepending a '-'.
+const struct {
+  const char* input;
+  int expected_output;
+} kValidNonNegativeTests[] = {
+    {"0", 0},     {"00000", 0}, {"003", 3}, {"003", 3}, {"1234566", 1234566},
+    {"987", 987}, {"010", 10},
+};
+
+// These are invalid inputs that can not be parsed regardless of the policy
+// used (they are neither valid negative or non-negative values).
+const char* kInvalidParseTests[] = {
+    "",       "-",      "--",    "23-",  "134-34", "- ",   "    ",  "+42",
+    " 123",   "123 ",   "123\n", "0xFF", "-0xFF",  "0x11", "-0x11", "x11",
+    "-x11",   "F11",    "-F11",  "AF",   "-AF",    "0AF",  "0.0",   "13.",
+    "13,000", "13.000", "13/5",  "Inf",  "NaN",    "null", "dog",
+};
+
+// This wrapper calls ParseIntegerBase10() and expects the result to match
+// |expected_output|.
+template <typename OutputType, typename ExpectationType>
+void ExpectParseIntegerBase10Success(const base::StringPiece& input,
+                                     ParseInteger policy,
+                                     ExpectationType expected_output) {
+  // Try parsing without specifying an error output - expecting success.
+  OutputType parsed_number1;
+  EXPECT_TRUE(ParseIntegerBase10(input, policy, &parsed_number1))
+      << "Failed to parse: " << input;
+  EXPECT_EQ(static_cast<OutputType>(expected_output), parsed_number1);
+
+  // Try parsing with an error output - expecting success.
+  ParseIntegerError kBogusError = static_cast<ParseIntegerError>(19);
+  ParseIntegerError error = kBogusError;
+  OutputType parsed_number2;
+  EXPECT_TRUE(ParseIntegerBase10(input, policy, &parsed_number2, &error))
+      << "Failed to parse: " << input;
+  EXPECT_EQ(static_cast<OutputType>(expected_output), parsed_number2);
+  // Check that the error output was not written to.
+  EXPECT_EQ(kBogusError, error);
+}
+
+// This wrapper calls ParseIntegerBase10() and expects the failure to match
+// |expected_error|.
+template <typename OutputType>
+void ExpectParseIntegerBase10Failure(const base::StringPiece& input,
+                                     ParseInteger policy,
+                                     ParseIntegerError expected_error) {
+  const OutputType kBogusOutput = OutputType(23614);
+
+  // Try parsing without specifying an error output - expecting failure.
+  OutputType parsed_number1 = kBogusOutput;
+  EXPECT_FALSE(ParseIntegerBase10(input, policy, &parsed_number1))
+      << "Succeded parsing: " << input;
+  EXPECT_EQ(kBogusOutput, parsed_number1)
+      << "Modified output when failed parsing";
+
+  // Try parsing with an error output - expecting failure.
+  OutputType parsed_number2 = kBogusOutput;
+  ParseIntegerError error;
+  EXPECT_FALSE(ParseIntegerBase10(input, policy, &parsed_number2, &error))
+      << "Succeded parsing: " << input;
+  EXPECT_EQ(kBogusOutput, parsed_number2)
+      << "Modified output when failed parsing";
+  EXPECT_EQ(expected_error, error);
+}
+
+// Common tests to run for each of the overloaded versions of
+// ParseIntegerBase10().
+template <typename T>
+void TestParseIntegerBase10() {
+  ParseInteger kPolicies[] = {ParseInteger::DISALLOW_NEGATIVE,
+                              ParseInteger::ALLOW_NEGATIVE};
+
+  // Test valid non-negative inputs
+
+  for (const auto& policy : kPolicies) {
+    for (const auto& test : kValidNonNegativeTests) {
+      ExpectParseIntegerBase10Success<T>(test.input, policy,
+                                         test.expected_output);
+    }
+  }
+
+  // Test invalid inputs (invalid regardless of parsing policy)
+
+  for (const auto& policy : kPolicies) {
+    for (const auto& input : kInvalidParseTests) {
+      ExpectParseIntegerBase10Failure<T>(input, policy,
+                                         ParseIntegerError::FAILED_PARSE);
+    }
+  }
+
+  // Test valid negative inputs (constructed from the valid non-negative test
+  // cases).
+
+  for (const auto& policy : kPolicies) {
+    for (const auto& test : kValidNonNegativeTests) {
+      std::string negative_input = std::string("-") + test.input;
+      int expected_negative_output = -test.expected_output;
+
+      // The result depends on the policy.
+      if (policy == ParseInteger::DISALLOW_NEGATIVE) {
+        ExpectParseIntegerBase10Failure<T>(negative_input, policy,
+                                           ParseIntegerError::FAILED_PARSE);
+      } else {
+        ExpectParseIntegerBase10Success<T>(negative_input, policy,
+                                           expected_negative_output);
+      }
+    }
+  }
+
+  // Test parsing the largest possible value for output type.
+
+  for (const auto& policy : kPolicies) {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseIntegerBase10Success<T>(std::to_string(value), policy, value);
+  }
+
+  // Test parsing a number one larger than the output type can accomodate
+  // (overflow).
+
+  for (const auto& policy : kPolicies) {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseIntegerBase10Failure<T>(IncrementLastChar(std::to_string(value)),
+                                       policy,
+                                       ParseIntegerError::FAILED_OVERFLOW);
+  }
+
+  // Test parsing a number at least as large as the output allows AND contains
+  // garbage at the end. This exercises an interesting internal quirk of
+  // base::StringToInt*(), in that its result cannot distinguish this case
+  // from overflow.
+
+  for (const auto& policy : kPolicies) {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseIntegerBase10Failure<T>(std::to_string(value) + " ", policy,
+                                       ParseIntegerError::FAILED_PARSE);
+  }
+
+  // Test parsing the smallest possible value for output type.
+
+  for (const auto& policy : kPolicies) {
+    const T value = std::numeric_limits<T>::min();
+    auto str_value = std::to_string(value);
+
+    // The minimal value is necessarily negative, since this function is testing
+    // only signed output types.
+    if (policy == ParseInteger::DISALLOW_NEGATIVE) {
+      ExpectParseIntegerBase10Failure<T>(str_value, policy,
+                                         ParseIntegerError::FAILED_PARSE);
+    } else {
+      ExpectParseIntegerBase10Success<T>(str_value, policy, value);
+    }
+  }
+
+  // Test parsing a number one less than the output type can accomodate
+  // (underflow).
+
+  {
+    std::string str_value =
+        IncrementLastChar(std::to_string(std::numeric_limits<T>::min()));
+
+    ExpectParseIntegerBase10Failure<T>(str_value, ParseInteger::ALLOW_NEGATIVE,
+                                       ParseIntegerError::FAILED_UNDERFLOW);
+  }
+
+  // Test parsing a string that contains a valid number followed by a NUL
+  // character.
+
+  for (const auto& policy : kPolicies) {
+    ExpectParseIntegerBase10Failure<T>(base::StringPiece("123\0", 4), policy,
+                                       ParseIntegerError::FAILED_PARSE);
   }
 }
 
-TEST(ParseNumberTest, IntInvalidInputs) {
-  const char* kTests[] = {
-      "",
-      "-23",
-      "+42",
-      " 123",
-      "123 ",
-      "123\n",
-      "0xFF",
-      "0x11",
-      "x11",
-      "F11",
-      "AF",
-      "0AF",
-      "0.0",
-      "13.",
-      "13,000",
-      "13.000",
-      "13/5",
-      "9999999999999999999999999999999999999999999999999999999999999999",
-      "Inf",
-      "NaN",
-      "null",
-      "dog",
-  };
-
-  for (const auto& input : kTests) {
-    int result = 0xDEAD;
-    ASSERT_FALSE(ParseNonNegativeDecimalInt(input, &result))
-        << "Succeeded to parse: " << input;
-    EXPECT_EQ(0xDEAD, result) << "Modified output for failed parsing";
+// This wrapper calls ParseUnsignedIntegerBase10() and expects the result to
+// match |expected_output|.
+template <typename OutputType, typename ExpectationType>
+void ExpectParseUnsignedIntegerBase10Success(const base::StringPiece& input,
+                                             ExpectationType expected_output) {
+  // Try parsing without specifying an error output - expecting success.
+  OutputType parsed_number1;
+  EXPECT_TRUE(ParseUnsignedIntegerBase10(input, &parsed_number1))
+      << "Failed to parse: " << input;
+  EXPECT_EQ(static_cast<OutputType>(expected_output), parsed_number1);
+
+  // Try parsing with an error output - expecting success.
+  ParseIntegerError kBogusError = static_cast<ParseIntegerError>(19);
+  ParseIntegerError error = kBogusError;
+  OutputType parsed_number2;
+  EXPECT_TRUE(ParseUnsignedIntegerBase10(input, &parsed_number2, &error))
+      << "Failed to parse: " << input;
+  EXPECT_EQ(static_cast<OutputType>(expected_output), parsed_number2);
+  // Check that the error output was not written to.
+  EXPECT_EQ(kBogusError, error);
+}
+
+// This wrapper calls ParseUnsignedIntegerBase10() and expects the failure to
+// match |expected_error|.
+template <typename OutputType>
+void ExpectParseUnsignedIntegerBase10Failure(const base::StringPiece& input,
+                                             ParseIntegerError expected_error) {
+  const OutputType kBogusOutput = OutputType(23614);
+
+  // Try parsing without specifying an error output - expecting failure.
+  OutputType parsed_number1 = kBogusOutput;
+  EXPECT_FALSE(ParseUnsignedIntegerBase10(input, &parsed_number1))
+      << "Succeded parsing: " << input;
+  EXPECT_EQ(kBogusOutput, parsed_number1)
+      << "Modified output when failed parsing";
+
+  // Try parsing with an error output - expecting failure.
+  OutputType parsed_number2 = kBogusOutput;
+  ParseIntegerError error;
+  EXPECT_FALSE(ParseUnsignedIntegerBase10(input, &parsed_number2, &error))
+      << "Succeded parsing: " << input;
+  EXPECT_EQ(kBogusOutput, parsed_number2)
+      << "Modified output when failed parsing";
+  EXPECT_EQ(expected_error, error);
+}
+
+// Common tests to run for each of the overloaded versions of
+// ParseUnsignedIntegerBase10().
+template <typename T>
+void TestParseUnsignedIntegerBase10() {
+  // Test valid non-negative inputs
+  for (const auto& test : kValidNonNegativeTests) {
+    ExpectParseUnsignedIntegerBase10Success<T>(test.input,
+                                               test.expected_output);
+  }
+
+  // Test invalid inputs (invalid regardless of parsing policy)
+  for (const auto& input : kInvalidParseTests) {
+    ExpectParseUnsignedIntegerBase10Failure<T>(input,
+                                               ParseIntegerError::FAILED_PARSE);
   }
+
+  // Test valid negative inputs (constructed from the valid non-negative test
+  // cases).
+  for (const auto& test : kValidNonNegativeTests) {
+    std::string negative_input = std::string("-") + test.input;
+
+    // The result depends on the policy.
+    ExpectParseUnsignedIntegerBase10Failure<T>(negative_input,
+                                               ParseIntegerError::FAILED_PARSE);
+  }
+
+  // Test parsing the largest possible value for output type.
+  {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseUnsignedIntegerBase10Success<T>(std::to_string(value), value);
+  }
+
+  // Test parsing a number one larger than the output type can accomodate
+  // (overflow).
+  {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseUnsignedIntegerBase10Failure<T>(
+        IncrementLastChar(std::to_string(value)),
+        ParseIntegerError::FAILED_OVERFLOW);
+  }
+
+  // Test parsing a number at least as large as the output allows AND contains
+  // garbage at the end. This exercises an interesting internal quirk of
+  // base::StringToInt*(), in that its result cannot distinguish this case
+  // from overflow.
+
+  {
+    const T value = std::numeric_limits<T>::max();
+    ExpectParseUnsignedIntegerBase10Failure<T>(std::to_string(value) + " ",
+                                               ParseIntegerError::FAILED_PARSE);
+  }
+
+  // Test parsing a string that contains a valid number followed by a NUL
+  // character.
+  ExpectParseUnsignedIntegerBase10Failure<T>(base::StringPiece("123\0", 4),
+                                             ParseIntegerError::FAILED_PARSE);
+}
+
+TEST(ParseNumberTest, ParseIntegerBase10Int32) {
+  TestParseIntegerBase10<int32_t>();
+}
+
+TEST(ParseNumberTest, ParseIntegerBase10Int64) {
+  TestParseIntegerBase10<int64_t>();
+}
+
+TEST(ParseNumberTest, ParseUnsignedIntegerBase10Uint32) {
+  TestParseUnsignedIntegerBase10<uint32_t>();
 }
 
-TEST(ParseNumberTest, IntInvalidInputsContainsNul) {
-  int result = 0xDEAD;
-  ASSERT_FALSE(
-      ParseNonNegativeDecimalInt(base::StringPiece("123\0", 4), &result));
-  EXPECT_EQ(0xDEAD, result);
+TEST(ParseNumberTest, ParseUnsignedIntegerBase10Uint64) {
+  TestParseUnsignedIntegerBase10<uint64_t>();
 }
 
 }  // namespace