libc/test/src/stdio/snprintf_test.cpp

   1 //===-- Unittests for snprintf --------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8
   9 #include "src/stdio/snprintf.h"
  10
  11 #include "test/UnitTest/Test.h"
  12
  13 // The sprintf test cases cover testing the shared printf functionality, so
  14 // these tests will focus on snprintf exclusive features.
  15
  16 TEST(LlvmLibcSNPrintfTest, CutOff) {
  17   char buff[64];
  18   int written;
  19
  20   written =
  21       __llvm_libc::snprintf(buff, 16, "A simple string with no conversions.");
  22   EXPECT_EQ(written, 36);
  23   ASSERT_STREQ(buff, "A simple string");
  24
  25   written = __llvm_libc::snprintf(buff, 5, "%s", "1234567890");
  26   EXPECT_EQ(written, 10);
  27   ASSERT_STREQ(buff, "1234");
  28
  29   // passing null as the output pointer is allowed as long as buffsz is 0.
  30   written = __llvm_libc::snprintf(nullptr, 0, "%s and more", "1234567890");
  31   EXPECT_EQ(written, 19);
  32 }
  33
  34 TEST(LlvmLibcSNPrintfTest, NoCutOff) {
  35   char buff[64];
  36   int written;
  37
  38   written =
  39       __llvm_libc::snprintf(buff, 37, "A simple string with no conversions.");
  40   EXPECT_EQ(written, 36);
  41   ASSERT_STREQ(buff, "A simple string with no conversions.");
  42
  43   written = __llvm_libc::snprintf(buff, 20, "%s", "1234567890");
  44   EXPECT_EQ(written, 10);
  45   ASSERT_STREQ(buff, "1234567890");
  46 }