zircon/system/ulib/fbl/test/string_printf_tests.cc

// Copyright 2016 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stdarg.h>

#include <fbl/array.h>
#include <fbl/string_printf.h>
#include <zxtest/zxtest.h>

namespace {

// Note: |runnable| can't be a reference since that'd make the behavior of
// |va_start()| undefined.
template <typename Runnable>
fbl::String VAListHelper(Runnable runnable, ...) {
  va_list ap;
  va_start(ap, runnable);
  fbl::String rv = runnable(ap);
  va_end(ap);
  return rv;
}

TEST(StringPrintfTest, Basic) {
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wformat-zero-length"
  EXPECT_STR_EQ("", fbl::StringPrintf("").c_str());
#pragma GCC diagnostic pop
  EXPECT_STR_EQ("hello", fbl::StringPrintf("hello").c_str());
  EXPECT_STR_EQ("hello-123", fbl::StringPrintf("hello%d", -123).c_str());
  EXPECT_STR_EQ("hello0123FACE", fbl::StringPrintf("%s%04d%X", "hello", 123, 0xfaceU).c_str());
}

TEST(StringPrintfTest, VprintfBasic) {
  EXPECT_STR_EQ("", VAListHelper([](va_list ap) -> fbl::String {
                      return fbl::StringVPrintf("", ap);
                    }).c_str());
  EXPECT_STR_EQ("hello", VAListHelper([](va_list ap) -> fbl::String {
                           return fbl::StringVPrintf("hello", ap);
                         }).c_str());
  EXPECT_STR_EQ(
      "hello-123",
      VAListHelper([](va_list ap) -> fbl::String { return fbl::StringVPrintf("hello%d", ap); },
                   -123)
          .c_str());
  EXPECT_STR_EQ(
      "hello0123FACE",
      VAListHelper([](va_list ap) -> fbl::String { return fbl::StringVPrintf("%s%04d%X", ap); },
                   "hello", 123, 0xfaceU)
          .c_str());
}

// Generally, we assume that everything forwards to |fbl::StringVPrintf()|, so
// testing |fbl::StringPrintf()| more carefully suffices.

TEST(StringPrintfTest, Boundary) {
  // Note: The size of strings generated should cover the boundary cases in the
  // constant |kStackBufferSize| in |StringVPrintf()|.
  for (size_t i = 800; i < 1200; i++) {
    fbl::String stuff(i, 'x');
    fbl::String format = fbl::String::Concat({stuff, "%d", "%s", " world"});
    EXPECT_STR_EQ(fbl::String::Concat({stuff, "123", "hello world"}).c_str(),
                  fbl::StringPrintf(format.c_str(), 123, "hello").c_str());
  }
}

TEST(StringPrintfTest, VeryBigString) {
  // 4 megabytes of exes (we'll generate 5 times this).
  fbl::String stuff(4u << 20u, 'x');
  fbl::String format = fbl::String::Concat({"%s", stuff, "%s", stuff, "%s"});
  EXPECT_STR_EQ(
      fbl::String::Concat({stuff, stuff, stuff, stuff, stuff}).c_str(),
      fbl::StringPrintf(format.c_str(), stuff.c_str(), stuff.c_str(), stuff.c_str()).c_str());
}

}  // namespace