Running tests in Go - Mini Project: Build & Apply

Running tests

📖 Scenario: You are working on a small Go program that adds two numbers. To make sure your code works correctly, you want to write a simple test.

🎯 Goal: Create a Go function that adds two integers, then write a test function to check if it returns the correct result.

📋 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.

Run the test using go test and print the result.

💡 Why This Matters

🌍 Real World

Writing tests helps catch mistakes early and makes your Go programs more reliable.

💼 Career

Testing is a key skill for software developers to ensure code quality and maintainability.

1

Create the Add function

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

Go

// Your code here

Hint

Define a function with two parameters and return their sum using return a + b.

2

Create the test function

Import the testing package and write a test function called TestAdd that takes t *testing.T as a parameter.

Go

package main

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

// Your code here

Hint

Use import "testing" and define func TestAdd(t *testing.T).

3

Add a test case inside TestAdd

Inside TestAdd, call Add(2, 3) and check if the result equals 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
}

func TestAdd(t *testing.T) {
    // Your code here
}

Hint

Store the result of Add(2, 3) in a variable, then compare it to 5. Use t.Errorf to show an error if it does not match.

4

Run the test and print the result

Run the test using the command go test in your terminal. Then write a comment showing the expected output: ok [package_name] 0.XXXs if the test passes.

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)
    }
}

// Run `go test` in terminal to see the result
// Your output here

Hint

Open your terminal, run go test in the folder with your code, and check that the output shows ok meaning the test passed.