EASYTUTORGUIDEC++ • C++23 / ISO/IEC 14882:2024

Testing and Debugging

C++ Chapter 56 of 60. Beginner-to-advanced teaching with a code example for every topic.

5 topics5 code examples10 Q&A

56.1 Unit Test Basics 56.2 Arrange-Act-Assert 56.3 Edge Cases 56.4 Mocks/Fakes Concepts 56.5 Automation and Coverage

56.1 Unit Test Basics

Unit Test Basics is part of Testing and Debugging. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

#include <iostream>
int main(){ /* Unit Test Basics */ std::cout<<"C++ example\n"; }

Step-by-step

Read the declarations and identify each value or object.
Follow execution from the first statement to the last.
Predict the output before running the example.
Run or compile it using the toolchain for this course.
Change one input and explain why the new result changes.

Expected result

The example should demonstrate Unit Test Basics with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

56.2 Arrange-Act-Assert

Arrange-Act-Assert is part of Testing and Debugging. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

#include <iostream>
int main(){ for(int i=1;i<=5;++i) std::cout<<i<<"\n"; }

Step-by-step

Read the declarations and identify each value or object.
Follow execution from the first statement to the last.
Predict the output before running the example.
Run or compile it using the toolchain for this course.
Change one input and explain why the new result changes.

Expected result

The example should demonstrate Arrange-Act-Assert with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

56.3 Edge Cases

Edge Cases is part of Testing and Debugging. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

#include <iostream>
int main(){ /* Edge Cases */ std::cout<<"C++ example\n"; }

Step-by-step

Read the declarations and identify each value or object.
Follow execution from the first statement to the last.
Predict the output before running the example.
Run or compile it using the toolchain for this course.
Change one input and explain why the new result changes.

Expected result

The example should demonstrate Edge Cases with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

56.4 Mocks/Fakes Concepts

Mocks/Fakes Concepts is part of Testing and Debugging. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

#include <iostream>
template<class T> T twice(T x){ return x+x; }
int main(){ std::cout<<twice(21)<<"\n"; }

Step-by-step

Read the declarations and identify each value or object.
Follow execution from the first statement to the last.
Predict the output before running the example.
Run or compile it using the toolchain for this course.
Change one input and explain why the new result changes.

Expected result

The example should demonstrate Mocks/Fakes Concepts with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.

56.5 Automation and Coverage

Automation and Coverage is part of Testing and Debugging. Learn what the construct does, the syntax it requires, how data moves through it, and the mistakes that can make the program incorrect or unsafe.

Why it matters

Use this feature when it makes the program clearer, safer, easier to maintain, or more efficient. Start with a small example before using it in a larger application.

Code example

#include <iostream>
int main(){ /* Automation and Coverage */ std::cout<<"C++ example\n"; }

Step-by-step

Read the declarations and identify each value or object.
Follow execution from the first statement to the last.
Predict the output before running the example.
Run or compile it using the toolchain for this course.
Change one input and explain why the new result changes.

Expected result

The example should demonstrate Automation and Coverage with a small, inspectable result. For platform-dependent or advanced examples, focus on the API pattern and verify the exact environment requirements.

Common mistakes

Common mistakes include using the feature before understanding lifetime/scope, ignoring errors, assuming conversions are harmless, or writing code that works only for one happy-path input.

Practice

Rewrite the example with different data. Add one edge case, predict the result, then test it. Explain the feature in your own words without looking at the lesson.