fmt/test/scan-test.cc

// Formatting library for C++ - scanning API test
//
// Copyright (c) 2019 - present, Victor Zverovich
// All rights reserved.
//
// For the license information refer to format.h.

#include "scan.h"

#include <time.h>

#include <climits>
#include <thread>

#include "fmt/os.h"
#include "gmock/gmock.h"
#include "gtest-extra.h"

TEST(scan_test, read_text) {
  fmt::string_view s = "foo";
  auto end = fmt::scan_to(s, "foo");
  EXPECT_EQ(end, s.end());
  EXPECT_THROW_MSG(fmt::scan_to("fob", "foo"), fmt::format_error,
                   "invalid input");
}

TEST(scan_test, read_int) {
  int n = 0;
  fmt::scan_to("42", "{}", n);
  EXPECT_EQ(n, 42);
  fmt::scan_to("-42", "{}", n);
  EXPECT_EQ(n, -42);
  fmt::scan_to("42", "{:}", n);
  EXPECT_EQ(n, 42);
  EXPECT_THROW_MSG(fmt::scan_to(std::to_string(INT_MAX + 1u), "{}", n),
                   fmt::format_error, "number is too big");
}

TEST(scan_test, read_longlong) {
  long long n = 0;
  fmt::scan_to("42", "{}", n);
  EXPECT_EQ(n, 42);
  fmt::scan_to("-42", "{}", n);
  EXPECT_EQ(n, -42);
}

TEST(scan_test, read_uint) {
  unsigned n = 0;
  fmt::scan_to("42", "{}", n);
  EXPECT_EQ(n, 42);
  EXPECT_THROW_MSG(fmt::scan_to("-42", "{}", n), fmt::format_error,
                   "invalid input");
}

TEST(scan_test, read_ulonglong) {
  unsigned long long n = 0;
  fmt::scan_to("42", "{}", n);
  EXPECT_EQ(n, 42);
  EXPECT_THROW_MSG(fmt::scan_to("-42", "{}", n), fmt::format_error,
                   "invalid input");
}

TEST(scan_test, read_hex) {
  unsigned n = 0;
  fmt::scan_to("2a", "{:x}", n);
  EXPECT_EQ(n, 42);
  auto num_digits = std::numeric_limits<unsigned>::digits / 4;
  EXPECT_THROW_MSG(
      fmt::scan_to(fmt::format("1{:0{}}", 0, num_digits), "{:x}", n),
      fmt::format_error, "number is too big");
}

TEST(scan_test, read_string) {
  std::string s;
  fmt::scan_to("foo", "{}", s);
  EXPECT_EQ(s, "foo");
}

TEST(scan_test, read_string_view) {
  fmt::string_view s;
  fmt::scan_to("foo", "{}", s);
  EXPECT_EQ(s, "foo");
}

TEST(scan_test, separator) {
  int n1 = 0, n2 = 0;
  fmt::scan_to("10 20", "{} {}", n1, n2);
  EXPECT_EQ(n1, 10);
  EXPECT_EQ(n2, 20);
}

struct num {
  int value;
};

namespace fmt {
template <> struct scanner<num> {
  bool hex = false;

  auto parse(scan_parse_context& ctx) -> scan_parse_context::iterator {
    auto it = ctx.begin(), end = ctx.end();
    if (it != end && *it == 'x') {
      hex = true;
      ++it;
    }
    if (it != end && *it != '}') throw_format_error("invalid format");
    return it;
  }

  template <class ScanContext>
  auto scan(num& n, ScanContext& ctx) const -> typename ScanContext::iterator {
    // TODO: handle specifier
    return fmt::scan(ctx, "{}", n.value);
  }
};
}  // namespace fmt

TEST(scan_test, read_custom) {
  auto n = num();
  fmt::scan_to("42", "{}", n);
  EXPECT_EQ(n.value, 42);
}

TEST(scan_test, invalid_format) {
  EXPECT_THROW_MSG(fmt::scan_to("", "{}"), fmt::format_error,
                   "argument index out of range");
  EXPECT_THROW_MSG(fmt::scan_to("", "{"), fmt::format_error,
                   "invalid format string");
}

TEST(scan_test, example) {
  std::string key;
  int value = 0;
  fmt::scan_to("answer = 42", "{} = {}", key, value);
  EXPECT_EQ(key, "answer");
  EXPECT_EQ(value, 42);
}

TEST(scan_test, end_of_input) {
  int value = 0;
  fmt::scan_to("", "{}", value);
}

#if FMT_USE_FCNTL
TEST(scan_test, file) {
  auto pipe = fmt::pipe();

  fmt::string_view input = "10 20";
  pipe.write_end.write(input.data(), input.size());
  pipe.write_end.close();

  int n1 = 0, n2 = 0;
  fmt::buffered_file f = pipe.read_end.fdopen("r");
  fmt::scan(f.get(), "{} {}", n1, n2);
  EXPECT_EQ(n1, 10);
  EXPECT_EQ(n2, 20);
}

TEST(scan_test, lock) {
  auto pipe = fmt::pipe();

  std::thread producer([&]() {
    fmt::string_view input = "42 ";
    for (int i = 0; i < 1000; ++i)
      pipe.write_end.write(input.data(), input.size());
    pipe.write_end.close();
  });

  std::atomic<int> count(0);
  fmt::buffered_file f = pipe.read_end.fdopen("r");
  auto fun = [&]() {
    int value = 0;
    while (fmt::scan(f.get(), "{}", value)) {
      if (value != 42) {
        pipe.read_end.close();
        EXPECT_EQ(value, 42);
        break;
      }
      ++count;
    }
  };
  std::thread consumer1(fun);
  std::thread consumer2(fun);

  producer.join();
  consumer1.join();
  consumer2.join();
  EXPECT_EQ(count, 1000);
}
#endif  // FMT_USE_FCNTL