Unit testing a vector string - c++

I have this really simple line of code in my production-code(A.cpp) as follows:
std::string A::getString(int i) {
return sVect_[i];
}
with the header as follows:
class A{
public:
std::string getString(int i);
...
private:
vector<std::string> sVect_;
...
};
I've been trying to test the getString() function using googletest but an error keeps popping out:
error: invalid conversion from 'char* (*)(const char*, int)throw ()' to 'int'
error: initializing argument 1 of 'std::string A::getString(i)'
This was my test program:
TEST(ATest, getString){
A a;
EXPECT_EQ("c", a.getString(i));
}
I couldn't quite grasp the workaround of the vector string and how to call it in my test program without ever changing the production code. I even use the hack, adding #define statements, to access the private member but still couldn't do it.
How do my test actually looks like to successfully call that function?
Note: I'm on Linux and using gcc. Thank you in advance guys.

Perhaps the error message is misleading. Have you defined i globally somewhere else? To me it looks like in the local scope because it does not know what the value of the variable i is, it is misbehaving in an unexpected way
TEST(ATest, getString){
A a;
EXPECT_EQ("c", a.getString(i)); //here what is the 'i' and where is it defined
}

Related

Can unity C unittest framework be used to unittest C++ code?

I'm using the unity framework to unittest my C code on an AtMega32A. This works great. now I wonder if I can somehow trick unity to also test my C++ code.
I've made a small proof of concept program that exposes all the members of the C++ class via a public function. Now I would like to put a number of assert macro's in that public function. The program can be found here:
https://github.com/cdwijs/cpp_unit_test
In my main I have the following:
int main(void)
{
UNITY_BEGIN();
//RUN_TEST(myPrivate.executeTest); //unity_internals.h(707,65): error: invalid use of non-static member function
//RUN_TEST((void*)myPrivate.executeTest); //error: invalid use of member function (did you forget the '()' ?)
//RUN_TEST((func)))myPrivate.executeTest); //error: 'func' was not declared in this scope
//RUN_TEST(&myPrivate.executeTest); //error: cannot convert 'void (Private::*)()' to 'UnityTestFunction {aka void (*)()}' for argument '1' to 'void UnityDefaultTestRun(UnityTestFunction, const char*, int)'
UNITY_END();
myPrivate.more();
myPrivate.more();
myPrivate.less();
/* Replace with your application code */
while (1)
{
}
}
And in Private_test.cpp I have the following:
#include "private.h"
#include "unity.h"
void Private::executeTest (void)
{
myNumber = 3;
TEST_ASSERT_EQUAL_INT(3,myNumber);
more();
TEST_ASSERT_EQUAL_INT(4,myNumber);
}
I can't figure out howto run the test function. Any Idea's? Am I looking in the correct direction, or should I use a test framework that is specifically aimed at C++?

Cannot convert string to char* for argument 1

I am having an issue with my C++ code for converting a string of numbers in base b to another base n. My error is as follows:
cannot convert ‘std::__cxx11::string {aka std::__cxx11::basic_string<char>}’ to ‘char*’ for argument ‘1’ to ‘int base_to_decimal(char*, int)’
I am using g++ to compile, and I have been for a while, so I thought at first I knew what the issue was. It says that the method base_to_decimal accepts two arguments: one of type char* and one of type int. So all I should have to do to fix my issue is change the char* argument to a string, right?
Well, I looked, and the code for the function in question is:
int base_to_decimal(std::string input_base, int base)
So this method SHOULD be expecting a string, but for some reason when I pass in a string, it gets angry at me.
If someone could help me figure this out, that would be fantastic. I am using g++ 7.3.0, and running all this on Linux Mint 19.1.
(EDIT)
Main Method
Functions
Table
You've written a custom declaration on line 46 of your main:
int base_to_decimal(char * input_base, int base)
But in the functions file where you've defined your function, you have:
int base_to_decimal(std::string input_base, int base)
This is why you should not write in-line declarations for external functions, but instead put the declarations in a header file. #include in the file where the function is later defined, ensures that the definition matches the declaration that the other files are expecting. And likewise, it enforces that all those other files are trying to use the function the way it's actually coded.

error: expected primary-expression before ')' token (C)

I am trying to call a function named characterSelection(SDL_Surface *screen, struct SelectionneNonSelectionne sel) which returns a void
This is the .h of the function I try to call:
struct SelectionneNonSelectionne;
void characterSelection(SDL_Surface *screen, struct SelectionneNonSelectionne);
void resetSelection(SDL_Surface *screen, struct SelectionneNonSelectionne);
On my main function, I try to call it like this:
characterSelection(screen, SelectionneNonSelectionne);
When I compile, I have the message:
error: expected primary-expression before ')' token
I made the includes. I suppose I miscall the second argument, my struct. But, I can't find why on the net.
Have you got any idea about what I did wrong?
You should create a variable of the type SelectionneNonSelectionne.
struct SelectionneNonSelectionne var;
After that pass that variable to the function like
characterSelection(screen, var);
The error is caused since you are passing the type name SelectionneNonSelectionne
A function call needs to be performed with objects. You are doing the equivalent of this:
// function declaration/definition
void foo(int) {}
// function call
foo(int); // wat!??
i.e. passing a type where an object is required. This makes no sense in C or C++. You need to be doing
int i = 42;
foo(i);
or
foo(42);
You're passing a type as an argument, not an object. You need to do characterSelection(screen, test); where test is of type SelectionneNonSelectionne.
I seen this problem with the latest nightly build of Code::Blocks. When I switched back to the stable release of Code::Blocks, 20.03 at the time of this writing, the problem went away and my code compiled and ran without problems. I'm not sure what Code::Blocks is doing, but it is very annoying. I got this repeatedly on a C++ project for every NULL in my code, forcing me to use nullptr instead.

brace initialized function pointer array: invalid conversion from 'void (*(*)())()' to 'void (*)()'

In my arduino sketch I need an array of function pointers with the signature void foo().
I'm using the ino command line utillity on linux (which uses avr-g++ under the hood).
However I'm getting a very strange error while defining the array.
error:
error: invalid conversion from ‘void (* (*)())()’ to ‘void (*)()’
in this piece of code
void (*mode_setup[])(void) = {
&show_time_setup,
&set_time_setup,
&set_alarm_setup,
&set_date_setup // <-- generates 3 identical error on this line
};
I don't understand what I'm doing wrong, since... int foo[] = { 1, 2, 3 }; ..is perfectly valid, and void (*foo)(void) is the syntax for function pointer.
what am I missing?
edit: NEVERMIND IM STUPID
the functions were not void foo(), but fptr foo() [fptr=function pointer typedef]
sincere appologies for wasting peoples time
I can reproduce your error message with this code
void (*foo())() {}
void (*arr[])(void) = { &foo };
So it looks like the signature of the function(s) is not what you think it is. An array to hold a pointer to foo would need to be declared like this:
void (*(*arr[])())(void) = {
&foo
};
If I were you, I'd consider typedefs...

Vector of pointer member functions c++

I have the following code:
typedef bool (A::*rule)(shared_ptr<Node >, shared_ptr<Node> ) ;
when initilaising the class A object, I run the following code
v_ = vector<rule>();
v_.push_back(A::memberFunction);
I have also tried with v_.push_back(&A::memberFunction) as this seemed more logical to me, but was
advised against on the forums. I also get an error message
This is as suggested by the many topics on the matter. However, I get the following error
non-const lvalue reference to type 'value_type' (aka 'bool (boost::shared_ptr<Node>, boost::shared_ptr<Node>)')
cannot bind to a temporary of type '<bound member function type>'
Does anyone know where I am going wrong?
I have also tried with v_.push_back(&A::memberFunction) as this seemed more logical to me, but was advised against on the forums.
I don't know what forums were those. Forming a pointer-to-member has a single valid syntax, and it is & classname::membername. All elements mandatory.
Use that consistently and post code and error message for that version should the problem persist.
This code compiles under llvm/clang 4.2 (As #balog-pal said, the & is mandatory before classname::membername:
#include <memory>
#include <vector>
struct Node {};
struct A
{
bool rule(std::shared_ptr<Node>, std::shared_ptr<Node>)
{return true;}
};
typedef bool (A::*rule)(std::shared_ptr<Node>, std::shared_ptr<Node> );
int main(int, const char**)
{
std::vector<rule> v;
v.push_back(&A::rule);
return 0;
}
Please post a full not-compiling example, your issue must be hidden somewhere else.