Writing basic test functions in Go - Mini Project: Build & Apply

Writing basic test functions

📖 Scenario: You are working on a simple calculator package in Go. You want to make sure your addition function works correctly by writing a basic test function.

🎯 Goal: Write a basic test function in Go to check if the Add function returns the correct sum.

📋 What You'll Learn

Create a function called Add that takes two integers and returns their sum.

Create a test function called TestAdd in the same package.

Use the testing package and t.Errorf to report errors.

Test that Add(2, 3) returns 5.

💡 Why This Matters

🌍 Real World

Writing tests helps catch mistakes early and ensures your code works as expected before others use it.

💼 Career

Testing is a key skill for software developers to maintain code quality and reliability in professional projects.

1

Create the Add function

Create a function called Add that takes two integers a and b and returns their sum as an integer.

Go

// Your code here

Hint

Define a function with func Add(a int, b int) int and return a + b.

2

Import testing package

Add an import statement for the testing package below the package main line.

Go

package main

// Your code here

func Add(a int, b int) int {
    return a + b
}

Hint

Use import "testing" to import the testing package.

3

Write the TestAdd function

Write a test function called TestAdd that takes t *testing.T as a parameter. Inside it, call Add(2, 3) and check if the result is 5. If not, use t.Errorf to report an error with the message "Add(2, 3) = %d; want 5".

Go

package main

import "testing"

func Add(a int, b int) int {
    return a + b
}

// Your code here

Hint

Define func TestAdd(t *testing.T), call Add(2, 3), and check if the result is 5. Use t.Errorf to report if not.

4

Run the test and print success message

Add a main function that calls TestAdd with a dummy *testing.T to simulate running the test, then print "Test completed".

Go

package main

import "testing"

func Add(a int, b int) int {
    return a + b
}

func TestAdd(t *testing.T) {
    result := Add(2, 3)
    if result != 5 {
        t.Errorf("Add(2, 3) = %d; want 5", result)
    }
}

// Your code here

Hint

Create a main function that calls TestAdd(&testing.T{}) and prints "Test completed".