src/lib/support/tests/TestCHIPMemString.cpp

/*
 *
 *    Copyright (c) 2021 Project CHIP Authors
 *    All rights reserved.
 *
 *    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
 *
 *        http://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.
 */

#include <inttypes.h>
#include <stdarg.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <gtest/gtest.h>

#include <lib/support/CHIPMemString.h>
#include <lib/support/CodeUtils.h>
#include <lib/support/ScopedBuffer.h>
#include <lib/support/Span.h>

using namespace chip;
using namespace chip::Platform;

// =================================
//      Unit tests
// =================================

class TestCHIPMemString : public ::testing::Test
{
public:
    static void SetUpTestSuite() { ASSERT_EQ(chip::Platform::MemoryInit(), CHIP_NO_ERROR); }
    static void TearDownTestSuite() { chip::Platform::MemoryShutdown(); }
};

namespace {
template <size_t kTestBufLen>
struct TestBuffers
{
    char correctSizeBuf[kTestBufLen];
    char tooSmallBuf[kTestBufLen - 1];
    char wayTooSmallBuf[1];
    char tooBigBuf[kTestBufLen + 10];
    void Reset()
    {
        memset(correctSizeBuf, 1, sizeof(correctSizeBuf));
        memset(tooSmallBuf, 1, sizeof(tooSmallBuf));
        memset(wayTooSmallBuf, 1, sizeof(wayTooSmallBuf));
        memset(tooBigBuf, 1, sizeof(tooBigBuf));
    }
    void CheckCorrectness(const char * testStr)
    {
        // correctSizeBuf and tooBigBuf should have the complete string.
        EXPECT_EQ(correctSizeBuf[kTestBufLen - 1], '\0');
        EXPECT_EQ(tooBigBuf[kTestBufLen - 1], '\0');
        EXPECT_STREQ(correctSizeBuf, testStr);
        EXPECT_STREQ(tooBigBuf, testStr);
        EXPECT_EQ(strlen(correctSizeBuf), strlen(testStr));
        EXPECT_EQ(strlen(tooBigBuf), strlen(testStr));

        // wayTooSmallBuf is tiny and thus will only have the null terminator
        EXPECT_EQ(wayTooSmallBuf[0], '\0');

        // tooSmallBuf should still have a null terminator on the end
        EXPECT_EQ(tooSmallBuf[kTestBufLen - 2], '\0');
        EXPECT_EQ(memcmp(tooSmallBuf, testStr, kTestBufLen - 2), 0);
    }
};

} // namespace

TEST_F(TestCHIPMemString, TestCopyString)
{
    static constexpr char testWord[] = "testytest";
    ByteSpan testWordSpan            = ByteSpan(reinterpret_cast<const uint8_t *>(testWord), sizeof(testWord) - 1);
    CharSpan testWordSpan2(testWord, sizeof(testWord) - 1);
    TestBuffers<sizeof(testWord)> testBuffers;

    // CopyString with explicit size
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, sizeof(testBuffers.correctSizeBuf), testWord);
    CopyString(testBuffers.tooSmallBuf, sizeof(testBuffers.tooSmallBuf), testWord);
    CopyString(testBuffers.wayTooSmallBuf, sizeof(testBuffers.wayTooSmallBuf), testWord);
    CopyString(testBuffers.tooBigBuf, sizeof(testBuffers.tooBigBuf), testWord);
    testBuffers.CheckCorrectness(testWord);

    // CopyString with array size
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, testWord);
    CopyString(testBuffers.tooSmallBuf, testWord);
    CopyString(testBuffers.wayTooSmallBuf, testWord);
    CopyString(testBuffers.tooBigBuf, testWord);
    testBuffers.CheckCorrectness(testWord);

    // CopyString with explicit size from ByteSpan
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, sizeof(testBuffers.correctSizeBuf), testWordSpan);
    CopyString(testBuffers.tooSmallBuf, sizeof(testBuffers.tooSmallBuf), testWordSpan);
    CopyString(testBuffers.wayTooSmallBuf, sizeof(testBuffers.wayTooSmallBuf), testWordSpan);
    CopyString(testBuffers.tooBigBuf, sizeof(testBuffers.tooBigBuf), testWordSpan);
    testBuffers.CheckCorrectness(testWord);

    // CopyString with array size from ByteSpan
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, testWordSpan);
    CopyString(testBuffers.tooSmallBuf, testWordSpan);
    CopyString(testBuffers.wayTooSmallBuf, testWordSpan);
    CopyString(testBuffers.tooBigBuf, testWordSpan);
    testBuffers.CheckCorrectness(testWord);

    // CopyString with explicit size from CharSpan
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, sizeof(testBuffers.correctSizeBuf), testWordSpan2);
    CopyString(testBuffers.tooSmallBuf, sizeof(testBuffers.tooSmallBuf), testWordSpan2);
    CopyString(testBuffers.wayTooSmallBuf, sizeof(testBuffers.wayTooSmallBuf), testWordSpan2);
    CopyString(testBuffers.tooBigBuf, sizeof(testBuffers.tooBigBuf), testWordSpan2);
    testBuffers.CheckCorrectness(testWord);

    // CopyString with array size from CharSpan
    testBuffers.Reset();
    CopyString(testBuffers.correctSizeBuf, testWordSpan2);
    CopyString(testBuffers.tooSmallBuf, testWordSpan2);
    CopyString(testBuffers.wayTooSmallBuf, testWordSpan2);
    CopyString(testBuffers.tooBigBuf, testWordSpan2);
    testBuffers.CheckCorrectness(testWord);
}

TEST_F(TestCHIPMemString, TestMemoryAllocString)
{
    static constexpr char testStr[] = "testytestString";
    char * allocatedStr             = MemoryAllocString(testStr, sizeof(testStr));
    ASSERT_NE(allocatedStr, nullptr);

    EXPECT_STREQ(testStr, allocatedStr);
    MemoryFree(allocatedStr);
}

TEST_F(TestCHIPMemString, TestScopedBuffer)
{
    // Scoped buffer has its own tests that check the memory properly. Here we are just testing that the string is copied in
    // properly.
    static constexpr char testStr[] = "testytestString";
    ScopedMemoryString scopedString = ScopedMemoryString(testStr, sizeof(testStr));
    EXPECT_STREQ(scopedString.Get(), testStr);
}