gmock/google-mock issues warning and fails the test with mocking exceptions

Question

I have coded a demo mock using google mock. The issue is that it is failing and not properly mocking. I cannot understand the issue here.

Code:

test/mock_turtle_test.cc

#include "mock_turtle.h"
#include "../painter.h"
#include <gtest/gtest.h>

using  ::testing::_;
using  ::testing::AtLeast;
using  ::testing::Return;
ACTION(MyException)
{
        throw(error_k());
}
TEST(PainterTest, CanDrawSomething) {
  Painter painter;
  EXPECT_CALL(*(painter.getTurtle()), PenDown())
      .Times(AtLeast(1))
      .WillOnce(MyException())
      .WillRepeatedly(Return(5));
  EXPECT_TRUE(painter.DrawCircle(0, 0, 10));
}

int main(int argc, char **argv) {
        testing::InitGoogleTest(&argc, argv);
        return RUN_ALL_TESTS();
}

inc/mock_turtle.h

#pragma once
#include <cstdlib>
#include "turtle.h"
#include <gmock/gmock.h>

class Turtle : public FakeTurtle{
 public:
  using FakeTurtle::FakeTurtle;
  MOCK_METHOD((void), PenUp, ());
  MOCK_METHOD((int), PenDown, ());
  MOCK_METHOD((void), Forward, (int distance));
  MOCK_METHOD((void), Turn, (int degrees));
  MOCK_METHOD((void), GoTo, (int x, int y));
  MOCK_METHOD((int), GetX, ());
  MOCK_METHOD((int), GetY, ());
};

inc/turtle.h

#pragma once

class FakeTurtle {

public:
  virtual ~FakeTurtle() {}
  virtual void PenUp() {};
  virtual int PenDown() {};
  virtual void Forward(int distance) {};
  virtual void Turn(int degrees) {};
  virtual void GoTo(int x, int y) {};
  virtual int GetX() const {};
  virtual int GetY() const {};

};

painter.h

#pragma once
#include "turtle.h"
#include <cerrno>

class error_k
{
public:
    error_k() : errnum(EAGAIN){}
    int num() const
    {
        return errnum;
    }
private:
    int errnum;
};

class Painter
{
        Turtle* turtle;
public:
        Painter() : turtle(new Turtle){}
    Turtle* getTurtle(){
        return turtle;
    }
        bool DrawCircle(int, int, int){
        int rep = 10;
        int ret = 0;
        do{
            try{
                std::cout << "calling PenDown() : rep = " <<
                    rep << " , ret = " << ret << std::endl;
                        ret = turtle->PenDown();
                if(ret > 0)
                    return true;
            }catch(error_k err )
            {
                std::cout << "Caught Exception (" <<
                    err.num() << "): rep = " <<
                    rep << " , ret = " << ret << std::endl;

                delete turtle;
                turtle = new Turtle();
            }
        }while(rep-- > 0 && ret == 0); 
                return false;
        }
    ~Painter(){
        delete turtle;
    }
};

CmakeLists.txt

cmake_minimum_required(VERSION 2.6)

# Locate GTest
find_package(GTest REQUIRED)
find_package(PkgConfig)
message(STATUS "gtest found: " ${GTEST_FOUND})
pkg_check_modules(GMOCK "gmock" REQUIRED)
message(STATUS "gmock found: " ${GMOCK_FOUND})

include_directories(${GTEST_INCLUDE_DIRS})

# Link runTests with what we want to test and the GTest and pthread library
add_executable(runTests test/mock_turtle_test.cc)
target_link_libraries(runTests ${GTEST_LIBRARIES} ${GMOCK_LIBRARIES} gmock gmock_main gtest gtest_main)
target_include_directories(runTests SYSTEM PRIVATE inc)
add_test(NAME runTests COMMAND runTests)
enable_testing()

Output:

$ ./runTests 
[==========] Running 1 test from 1 test suite.
[----------] Global test environment set-up.
[----------] 1 test from PainterTest
[ RUN      ] PainterTest.CanDrawSomething
calling PenDown() : rep = 10 , ret = 0
Caught Exception (11): rep = 10 , ret = 0
calling PenDown() : rep = 9 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 8 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 7 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 6 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 5 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 4 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 3 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 2 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 1 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
calling PenDown() : rep = 0 , ret = 0

GMOCK WARNING:
Uninteresting mock function call - returning default value.
    Function call: PenDown()
          Returns: 0
NOTE: You can safely ignore the above warning unless this call should not happen.  Do not suppress it by blindly adding an EXPECT_CALL() if you don't mean to enforce the call.  See https://github.com/google/googletest/blob/master/googlemock/docs/cook_book.md#knowing-when-to-expect for details.
/home/preetam/Desktop/gmock/cpp_mock_ptr/test/mock_turtle_test.cc:18: Failure
Value of: painter.DrawCircle(0, 0, 10)
  Actual: false
Expected: true
[  FAILED  ] PainterTest.CanDrawSomething (1 ms)
[----------] 1 test from PainterTest (1 ms total)

[----------] Global test environment tear-down
[==========] 1 test from 1 test suite ran. (1 ms total)
[  PASSED  ] 0 tests.
[  FAILED  ] 1 test, listed below:
[  FAILED  ] PainterTest.CanDrawSomething

 1 FAILED TEST

I suggest to have a look at [How to create a Minimal, Reproducible Example](https://stackoverflow.com/help/minimal-reproducible-example). I also suggest to revise your question's tags; e.g. how's `tdd` related to this problem? Possibly you want to include the ``c++`` tag? — Ivo Mori, Jun 11 '20 at 05:12
The example is minimal. Its not big by any means. The output from execution is the one that takes up most of the space. It is relevant though. — preetam, Jun 11 '20 at 06:35

score 0 · Answer 1 · answered Jun 11 '20 at 18:40

0

You define the expectation on the original turtle mock, but after the first exception you delete and re-create the mock. After that, the new mock has no expectations defined on it and as such all calls to it are reported as uninteresting.

answered Jun 11 '20 at 18:40

VladLosev

7,296
2
35
46

Yes. But how do you test this and address the issue. Turtle is a third party library and as such you cannot change signatures of functions. – preetam Jun 11 '20 at 18:45
The simplest course of action is to avoid destroying and re-creating your turtle object repeatedly when you catch the exception. If that's not possible, you can modify your Painter class to inject a factory for Turtle objects and during tests, inject a factory producing already configured mocks - each one configured for a single call. – VladLosev Jun 13 '20 at 21:45

gmock/google-mock issues warning and fails the test with mocking exceptions

1 Answers1

Linked