tor-browser

str_join_test.cc (18313B)

---

// Copyright 2017 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// Unit tests for all join.h functions

#include "absl/strings/str_join.h"

#include <cstddef>
#include <cstdint>
#include <cstdio>
#include <functional>
#include <initializer_list>
#include <iterator>
#include <map>
#include <memory>
#include <ostream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>

#include "gtest/gtest.h"
#include "absl/base/macros.h"
#include "absl/memory/memory.h"
#include "absl/strings/str_cat.h"
#include "absl/strings/str_split.h"
#include "absl/strings/string_view.h"

namespace {

TEST(StrJoin, APIExamples) {
 {
   // Collection of strings
   std::vector<std::string> v = {"foo", "bar", "baz"};
   EXPECT_EQ("foo-bar-baz", absl::StrJoin(v, "-"));
 }

 {
   // Collection of absl::string_view
   std::vector<absl::string_view> v = {"foo", "bar", "baz"};
   EXPECT_EQ("foo-bar-baz", absl::StrJoin(v, "-"));
 }

 {
   // Collection of const char*
   std::vector<const char*> v = {"foo", "bar", "baz"};
   EXPECT_EQ("foo-bar-baz", absl::StrJoin(v, "-"));
 }

 {
   // Collection of non-const char*
   std::string a = "foo", b = "bar", c = "baz";
   std::vector<char*> v = {&a[0], &b[0], &c[0]};
   EXPECT_EQ("foo-bar-baz", absl::StrJoin(v, "-"));
 }

 {
   // Collection of ints
   std::vector<int> v = {1, 2, 3, -4};
   EXPECT_EQ("1-2-3--4", absl::StrJoin(v, "-"));
 }

 {
   // Literals passed as a std::initializer_list
   std::string s = absl::StrJoin({"a", "b", "c"}, "-");
   EXPECT_EQ("a-b-c", s);
 }
 {
   // Join a std::tuple<T...>.
   std::string s = absl::StrJoin(std::make_tuple(123, "abc", 0.456), "-");
   EXPECT_EQ("123-abc-0.456", s);
 }

 {
   // Collection of unique_ptrs
   std::vector<std::unique_ptr<int>> v;
   v.emplace_back(new int(1));
   v.emplace_back(new int(2));
   v.emplace_back(new int(3));
   EXPECT_EQ("1-2-3", absl::StrJoin(v, "-"));
 }

 {
   // Array of ints
   const int a[] = {1, 2, 3, -4};
   EXPECT_EQ("1-2-3--4", absl::StrJoin(a, a + ABSL_ARRAYSIZE(a), "-"));
 }

 {
   // Collection of pointers
   int x = 1, y = 2, z = 3;
   std::vector<int*> v = {&x, &y, &z};
   EXPECT_EQ("1-2-3", absl::StrJoin(v, "-"));
 }

 {
   // Collection of pointers to pointers
   int x = 1, y = 2, z = 3;
   int *px = &x, *py = &y, *pz = &z;
   std::vector<int**> v = {&px, &py, &pz};
   EXPECT_EQ("1-2-3", absl::StrJoin(v, "-"));
 }

 {
   // Collection of pointers to std::string
   std::string a("a"), b("b");
   std::vector<std::string*> v = {&a, &b};
   EXPECT_EQ("a-b", absl::StrJoin(v, "-"));
 }

 {
   // A std::map, which is a collection of std::pair<>s.
   std::map<std::string, int> m = {{"a", 1}, {"b", 2}, {"c", 3}};
   EXPECT_EQ("a=1,b=2,c=3", absl::StrJoin(m, ",", absl::PairFormatter("=")));
 }

 {
   // Shows absl::StrSplit and absl::StrJoin working together. This example is
   // equivalent to s/=/-/g.
   const std::string s = "a=b=c=d";
   EXPECT_EQ("a-b-c-d", absl::StrJoin(absl::StrSplit(s, "="), "-"));
 }

 //
 // A few examples of edge cases
 //

 {
   // Empty range yields an empty string.
   std::vector<std::string> v;
   EXPECT_EQ("", absl::StrJoin(v, "-"));
 }

 {
   // A range of 1 element gives a string with that element but no
   // separator.
   std::vector<std::string> v = {"foo"};
   EXPECT_EQ("foo", absl::StrJoin(v, "-"));
 }

 {
   // A range with a single empty string element
   std::vector<std::string> v = {""};
   EXPECT_EQ("", absl::StrJoin(v, "-"));
 }

 {
   // A range with 2 elements, one of which is an empty string
   std::vector<std::string> v = {"a", ""};
   EXPECT_EQ("a-", absl::StrJoin(v, "-"));
 }

 {
   // A range with 2 empty elements.
   std::vector<std::string> v = {"", ""};
   EXPECT_EQ("-", absl::StrJoin(v, "-"));
 }

 {
   // A std::vector of bool.
   std::vector<bool> v = {true, false, true};
   EXPECT_EQ("1-0-1", absl::StrJoin(v, "-"));
 }
}

TEST(StrJoin, CustomFormatter) {
 std::vector<std::string> v{"One", "Two", "Three"};
 {
   std::string joined =
       absl::StrJoin(v, "", [](std::string* out, const std::string& in) {
         absl::StrAppend(out, "(", in, ")");
       });
   EXPECT_EQ("(One)(Two)(Three)", joined);
 }
 {
   class ImmovableFormatter {
    public:
     void operator()(std::string* out, const std::string& in) {
       absl::StrAppend(out, "(", in, ")");
     }
     ImmovableFormatter() {}
     ImmovableFormatter(const ImmovableFormatter&) = delete;
   };
   EXPECT_EQ("(One)(Two)(Three)", absl::StrJoin(v, "", ImmovableFormatter()));
 }
 {
   class OverloadedFormatter {
    public:
     void operator()(std::string* out, const std::string& in) {
       absl::StrAppend(out, "(", in, ")");
     }
     void operator()(std::string* out, const std::string& in) const {
       absl::StrAppend(out, "[", in, "]");
     }
   };
   EXPECT_EQ("(One)(Two)(Three)", absl::StrJoin(v, "", OverloadedFormatter()));
   const OverloadedFormatter fmt = {};
   EXPECT_EQ("[One][Two][Three]", absl::StrJoin(v, "", fmt));
 }
}

//
// Tests the Formatters
//

TEST(AlphaNumFormatter, FormatterAPI) {
 // Not an exhaustive test. See strings/strcat_test.h for the exhaustive test
 // of what AlphaNum can convert.
 auto f = absl::AlphaNumFormatter();
 std::string s;
 f(&s, "Testing: ");
 f(&s, static_cast<int>(1));
 f(&s, static_cast<int16_t>(2));
 f(&s, static_cast<int64_t>(3));
 f(&s, static_cast<float>(4));
 f(&s, static_cast<double>(5));
 f(&s, static_cast<unsigned>(6));
 f(&s, static_cast<size_t>(7));
 f(&s, absl::string_view(" OK"));
 EXPECT_EQ("Testing: 1234567 OK", s);
}

// Make sure people who are mistakenly using std::vector<bool> even though
// they're not memory-constrained can use absl::AlphaNumFormatter().
TEST(AlphaNumFormatter, VectorOfBool) {
 auto f = absl::AlphaNumFormatter();
 std::string s;
 std::vector<bool> v = {true, false, true};
 f(&s, *v.cbegin());
 f(&s, *v.begin());
 f(&s, v[1]);
 EXPECT_EQ("110", s);
}

TEST(AlphaNumFormatter, AlphaNum) {
 auto f = absl::AlphaNumFormatter();
 std::string s;
 f(&s, absl::AlphaNum("hello"));
 EXPECT_EQ("hello", s);
}

struct StreamableType {
 std::string contents;
};
inline std::ostream& operator<<(std::ostream& os, const StreamableType& t) {
 os << "Streamable:" << t.contents;
 return os;
}

TEST(StreamFormatter, FormatterAPI) {
 auto f = absl::StreamFormatter();
 std::string s;
 f(&s, "Testing: ");
 f(&s, static_cast<int>(1));
 f(&s, static_cast<int16_t>(2));
 f(&s, static_cast<int64_t>(3));
 f(&s, static_cast<float>(4));
 f(&s, static_cast<double>(5));
 f(&s, static_cast<unsigned>(6));
 f(&s, static_cast<size_t>(7));
 f(&s, absl::string_view(" OK "));
 StreamableType streamable = {"object"};
 f(&s, streamable);
 EXPECT_EQ("Testing: 1234567 OK Streamable:object", s);
}

// A dummy formatter that wraps each element in parens. Used in some tests
// below.
struct TestingParenFormatter {
 template <typename T>
 void operator()(std::string* s, const T& t) {
   absl::StrAppend(s, "(", t, ")");
 }
};

TEST(PairFormatter, FormatterAPI) {
 {
   // Tests default PairFormatter(sep) that uses AlphaNumFormatter for the
   // 'first' and 'second' members.
   const auto f = absl::PairFormatter("=");
   std::string s;
   f(&s, std::make_pair("a", "b"));
   f(&s, std::make_pair(1, 2));
   EXPECT_EQ("a=b1=2", s);
 }

 {
   // Tests using a custom formatter for the 'first' and 'second' members.
   auto f = absl::PairFormatter(TestingParenFormatter(), "=",
                                TestingParenFormatter());
   std::string s;
   f(&s, std::make_pair("a", "b"));
   f(&s, std::make_pair(1, 2));
   EXPECT_EQ("(a)=(b)(1)=(2)", s);
 }
}

TEST(DereferenceFormatter, FormatterAPI) {
 {
   // Tests wrapping the default AlphaNumFormatter.
   const absl::strings_internal::DereferenceFormatterImpl<
       absl::strings_internal::AlphaNumFormatterImpl>
       f;
   int x = 1, y = 2, z = 3;
   std::string s;
   f(&s, &x);
   f(&s, &y);
   f(&s, &z);
   EXPECT_EQ("123", s);
 }

 {
   // Tests wrapping std::string's default formatter.
   absl::strings_internal::DereferenceFormatterImpl<
       absl::strings_internal::DefaultFormatter<std::string>::Type>
       f;

   std::string x = "x";
   std::string y = "y";
   std::string z = "z";
   std::string s;
   f(&s, &x);
   f(&s, &y);
   f(&s, &z);
   EXPECT_EQ(s, "xyz");
 }

 {
   // Tests wrapping a custom formatter.
   auto f = absl::DereferenceFormatter(TestingParenFormatter());
   int x = 1, y = 2, z = 3;
   std::string s;
   f(&s, &x);
   f(&s, &y);
   f(&s, &z);
   EXPECT_EQ("(1)(2)(3)", s);
 }

 {
   absl::strings_internal::DereferenceFormatterImpl<
       absl::strings_internal::AlphaNumFormatterImpl>
       f;
   auto x = std::unique_ptr<int>(new int(1));
   auto y = std::unique_ptr<int>(new int(2));
   auto z = std::unique_ptr<int>(new int(3));
   std::string s;
   f(&s, x);
   f(&s, y);
   f(&s, z);
   EXPECT_EQ("123", s);
 }
}

//
// Tests the interfaces for the 4 public Join function overloads. The semantics
// of the algorithm is covered in the above APIExamples test.
//
TEST(StrJoin, PublicAPIOverloads) {
 std::vector<std::string> v = {"a", "b", "c"};

 // Iterators + formatter
 EXPECT_EQ("a-b-c",
           absl::StrJoin(v.begin(), v.end(), "-", absl::AlphaNumFormatter()));
 // Range + formatter
 EXPECT_EQ("a-b-c", absl::StrJoin(v, "-", absl::AlphaNumFormatter()));
 // Iterators, no formatter
 EXPECT_EQ("a-b-c", absl::StrJoin(v.begin(), v.end(), "-"));
 // Range, no formatter
 EXPECT_EQ("a-b-c", absl::StrJoin(v, "-"));
}

TEST(StrJoin, Array) {
 const absl::string_view a[] = {"a", "b", "c"};
 EXPECT_EQ("a-b-c", absl::StrJoin(a, "-"));
}

TEST(StrJoin, InitializerList) {
 { EXPECT_EQ("a-b-c", absl::StrJoin({"a", "b", "c"}, "-")); }

 {
   auto a = {"a", "b", "c"};
   EXPECT_EQ("a-b-c", absl::StrJoin(a, "-"));
 }

 {
   std::initializer_list<const char*> a = {"a", "b", "c"};
   EXPECT_EQ("a-b-c", absl::StrJoin(a, "-"));
 }

 {
   std::initializer_list<std::string> a = {"a", "b", "c"};
   EXPECT_EQ("a-b-c", absl::StrJoin(a, "-"));
 }

 {
   std::initializer_list<absl::string_view> a = {"a", "b", "c"};
   EXPECT_EQ("a-b-c", absl::StrJoin(a, "-"));
 }

 {
   // Tests initializer_list with a non-default formatter
   auto a = {"a", "b", "c"};
   TestingParenFormatter f;
   EXPECT_EQ("(a)-(b)-(c)", absl::StrJoin(a, "-", f));
 }

 {
   // initializer_list of ints
   EXPECT_EQ("1-2-3", absl::StrJoin({1, 2, 3}, "-"));
 }

 {
   // Tests initializer_list of ints with a non-default formatter
   auto a = {1, 2, 3};
   TestingParenFormatter f;
   EXPECT_EQ("(1)-(2)-(3)", absl::StrJoin(a, "-", f));
 }
}

TEST(StrJoin, StringViewInitializerList) {
 {
   // Tests initializer_list of string_views
   std::string b = "b";
   EXPECT_EQ("a-b-c", absl::StrJoin({"a", b, "c"}, "-"));
 }
 {
   // Tests initializer_list of string_views with a non-default formatter
   TestingParenFormatter f;
   std::string b = "b";
   EXPECT_EQ("(a)-(b)-(c)", absl::StrJoin({"a", b, "c"}, "-", f));
 }

 class NoCopy {
  public:
   explicit NoCopy(absl::string_view view) : view_(view) {}
   NoCopy(const NoCopy&) = delete;
   operator absl::string_view() { return view_; }  // NOLINT
  private:
   absl::string_view view_;
 };
 {
   // Tests initializer_list of string_views preferred over initializer_list<T>
   // for T that is implicitly convertible to string_view
   EXPECT_EQ("a-b-c",
             absl::StrJoin({NoCopy("a"), NoCopy("b"), NoCopy("c")}, "-"));
 }
 {
   // Tests initializer_list of string_views preferred over initializer_list<T>
   // for T that is implicitly convertible to string_view
   TestingParenFormatter f;
   EXPECT_EQ("(a)-(b)-(c)",
             absl::StrJoin({NoCopy("a"), NoCopy("b"), NoCopy("c")}, "-", f));
 }
}

TEST(StrJoin, Tuple) {
 EXPECT_EQ("", absl::StrJoin(std::make_tuple(), "-"));
 EXPECT_EQ("hello", absl::StrJoin(std::make_tuple("hello"), "-"));

 int x(10);
 std::string y("hello");
 double z(3.14);
 EXPECT_EQ("10-hello-3.14", absl::StrJoin(std::make_tuple(x, y, z), "-"));

 // Faster! Faster!!
 EXPECT_EQ("10-hello-3.14",
           absl::StrJoin(std::make_tuple(x, std::cref(y), z), "-"));

 struct TestFormatter {
   char buffer[128];
   void operator()(std::string* out, int v) {
     snprintf(buffer, sizeof(buffer), "%#.8x", v);
     out->append(buffer);
   }
   void operator()(std::string* out, double v) {
     snprintf(buffer, sizeof(buffer), "%#.0f", v);
     out->append(buffer);
   }
   void operator()(std::string* out, const std::string& v) {
     snprintf(buffer, sizeof(buffer), "%.4s", v.c_str());
     out->append(buffer);
   }
 };
 EXPECT_EQ("0x0000000a-hell-3.",
           absl::StrJoin(std::make_tuple(x, y, z), "-", TestFormatter()));
 EXPECT_EQ(
     "0x0000000a-hell-3.",
     absl::StrJoin(std::make_tuple(x, std::cref(y), z), "-", TestFormatter()));
 EXPECT_EQ("0x0000000a-hell-3.",
           absl::StrJoin(std::make_tuple(&x, &y, &z), "-",
                         absl::DereferenceFormatter(TestFormatter())));
 EXPECT_EQ("0x0000000a-hell-3.",
           absl::StrJoin(std::make_tuple(absl::make_unique<int>(x),
                                         absl::make_unique<std::string>(y),
                                         absl::make_unique<double>(z)),
                         "-", absl::DereferenceFormatter(TestFormatter())));
 EXPECT_EQ("0x0000000a-hell-3.",
           absl::StrJoin(std::make_tuple(absl::make_unique<int>(x), &y, &z),
                         "-", absl::DereferenceFormatter(TestFormatter())));
}

// A minimal value type for `StrJoin` inputs.
// Used to ensure we do not excessively require more a specific type, such as a
// `string_view`.
//
// Anything that can be  `data()` and `size()` is OK.
class TestValue {
public:
 TestValue(const char* data, size_t size) : data_(data), size_(size) {}
 const char* data() const { return data_; }
 size_t size() const { return size_; }

private:
 const char* data_;
 size_t size_;
};

// A minimal C++20 forward iterator, used to test that we do not impose
// excessive requirements on StrJoin inputs.
//
// The 2 main differences between pre-C++20 LegacyForwardIterator and the
// C++20 ForwardIterator are:
// 1. `operator->` is not required in C++20.
// 2. `operator*` result does not need to be an lvalue (a reference).
//
// The `operator->` requirement was removed on page 17 in:
// http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2018/p1037r0.pdf
//
// See the `[iterator.requirements]` section of the C++ standard.
//
// The value type is a template parameter so that we can test the behaviour
// of `StrJoin` specializations, e.g. the NoFormatter specialization for
// `string_view`.
template <typename ValueT>
class TestIterator {
public:
 using iterator_category = std::forward_iterator_tag;
 using value_type = ValueT;
 using pointer = void;
 using reference = const value_type&;
 using difference_type = int;

 // `data` must outlive the result.
 static TestIterator begin(const std::vector<absl::string_view>& data) {
   return TestIterator(&data, 0);
 }

 static TestIterator end(const std::vector<absl::string_view>& data) {
   return TestIterator(nullptr, data.size());
 }

 bool operator==(const TestIterator& other) const {
   return pos_ == other.pos_;
 }
 bool operator!=(const TestIterator& other) const {
   return pos_ != other.pos_;
 }

 // This deliberately returns a `prvalue`.
 // The requirement to return a reference was removed in C++20.
 value_type operator*() const {
   return ValueT((*data_)[pos_].data(), (*data_)[pos_].size());
 }

 // `operator->()` is deliberately omitted.
 // The requirement to provide it was removed in C++20.

 TestIterator& operator++() {
   ++pos_;
   return *this;
 }

 TestIterator operator++(int) {
   TestIterator result = *this;
   ++(*this);
   return result;
 }

 TestIterator& operator--() {
   --pos_;
   return *this;
 }

 TestIterator operator--(int) {
   TestIterator result = *this;
   --(*this);
   return result;
 }

private:
 TestIterator(const std::vector<absl::string_view>* data, size_t pos)
     : data_(data), pos_(pos) {}

 const std::vector<absl::string_view>* data_;
 size_t pos_;
};

template <typename ValueT>
class TestIteratorRange {
public:
 // `data` must be non-null and must outlive the result.
 explicit TestIteratorRange(const std::vector<absl::string_view>& data)
     : begin_(TestIterator<ValueT>::begin(data)),
       end_(TestIterator<ValueT>::end(data)) {}

 const TestIterator<ValueT>& begin() const { return begin_; }
 const TestIterator<ValueT>& end() const { return end_; }

private:
 TestIterator<ValueT> begin_;
 TestIterator<ValueT> end_;
};

TEST(StrJoin, TestIteratorRequirementsNoFormatter) {
 const std::vector<absl::string_view> a = {"a", "b", "c"};

 // When the value type is string-like (`std::string` or `string_view`),
 // the NoFormatter template specialization is used internally.
 EXPECT_EQ("a-b-c",
           absl::StrJoin(TestIteratorRange<absl::string_view>(a), "-"));
}

TEST(StrJoin, TestIteratorRequirementsCustomFormatter) {
 const std::vector<absl::string_view> a = {"a", "b", "c"};
 EXPECT_EQ("a-b-c",
           absl::StrJoin(TestIteratorRange<TestValue>(a), "-",
                         [](std::string* out, const TestValue& value) {
                           absl::StrAppend(
                               out,
                               absl::string_view(value.data(), value.size()));
                         }));
}

}  // namespace