没有默认构造函数时如何在 Googletest 夹具中定义变量？

Question

我有以下


#include <semsim/Subject.h>
#include <semsim/Triple.h>
#include "gtest/gtest.h"

class TripleTests : public ::testing::Test {
public:

    std::string subject_str;
    semsim::Subject subject;

    void SetUp() override {
        subject_str = "./MyModel#metaid_0";
        subject = semsim::Subject(subject_str);
    }
};

TEST_F(TripleTests, TestSubjectMetaId) { // this line causes the error
    std::cout << subject << std::endl;
}

为了定义变量（供以后在 TEST_F 函数中使用），必须在 class 范围内创建它们，然后在 SetUp 方法中填充一个值.这是因为我无法将 subject_str 传递给 class 级别的 Subject。但是，如果在 class 级别实例化变量，它会使用默认构造函数，而我的 class 没有（也不需要）默认构造函数。这是我 IDE 的投诉：

Call to implicitly-deleted default constructor of 'TripleTests' because field 'subject' has no default constructor

因此我的问题是：在不需要定义默认构造函数的情况下，我如何在 TripleTest class 中创建一个主题 object 以便它可以在 [=15] 中使用=] 功能？或者是否有必要在 Suject 中默认构造函数，以便我可以在测试夹具中创建一个？

供参考，Subject header 如下所示：

    class Subject {
    private:
        std::string metaId;

    public:

        explicit Subject(std::string metaId) : metaId(std::move(metaId)) {};

        const std::string &getMetaId() const;

        bool operator==(const Subject &rhs) const;

        bool operator!=(const Subject &rhs) const;

        friend std::ostream &operator<<(std::ostream &os, const Subject &subject);
    };

}

编辑

@Tomasz 的回答


class TripleTests : public ::testing::Test {
public:

    std::string subject_str;
    semsim::Subject subject;
    // alternative 1
    TripleTests()  {
        this->subject_str = "./MyModel#metaid_0";
        semsim::Subject s(subject_str);
        this->subject = s;
    }

    // alternative 2
    TripleTests()  {
        this->subject_str = "./MyModel#metaid_0";
        this->subject = semsim::Subject(subject_str);
    }

结果

Constructor for 'TripleTests' must explicitly initialize the member 'subject' which does not have a default constructor. Isn't the line `this->subject = s` initialising the member `subject`?

Answer 1

您必须使用 fixture 的构造函数而不是 SetUp() 来初始化初始化列表中的成员:

class TripleTests : public ::testing::Test {
public:

    std::string subject_str;
    semsim::Subject subject;

    TripleTests() 
        : subject_str("./MyModel#metaid_0")
        , subject(subject_str)
    {
    }
};

没有默认构造函数时如何在 Googletest 夹具中定义变量？

How to define variables in Googletest fixtures when they do not have a default constructor?

c++

googletest

编辑