Introduction

Baby Steps is a fundamental concept in Test-Driven Development that emphasizes making small, incremental changes to the codebase. This article explores how to effectively implement Baby Steps in your TDD practice.

What are Baby Steps?

Baby Steps refer to the practice of making the smallest possible change that could possibly work to get a test passing. This approach helps developers:

  • Maintain focus on the current task
  • Reduce cognitive load
  • Build confidence in the code
  • Create a clear history of changes

How to Take Baby Steps

1. Start with the Simplest Test

Begin with the most basic test case that could possibly work:


test('empty string returns empty string', () => {
    expect(reverse('')).toBe('');
});

2. Make the Simplest Implementation

Implement the minimum code needed to pass the test:


function reverse(str) {
    return '';
}

3. Add Another Simple Test


test('single character returns same character', () => {
    expect(reverse('a')).toBe('a');
});

4. Implement the Next Simplest Solution


function reverse(str) {
    return str;
}

Benefits of Baby Steps

  • Reduced complexity in each change
  • Easier to understand and review
  • Faster feedback cycles
  • Better error isolation
  • Increased confidence in changes

Common Challenges

  • Resisting the urge to over-engineer
  • Finding the right step size
  • Maintaining momentum
  • Dealing with complex requirements

Tips for Success

  • Commit after each passing test
  • Use meaningful commit messages
  • Review your steps regularly
  • Pair program to maintain discipline

Example: Building a Stack


// Step 1: Empty stack
test('new stack is empty', () => {
    const stack = new Stack();
    expect(stack.isEmpty()).toBe(true);
});

// Step 2: Push one item
test('stack with one item is not empty', () => {
    const stack = new Stack();
    stack.push(1);
    expect(stack.isEmpty()).toBe(false);
});

// Step 3: Pop item
test('pop returns last pushed item', () => {
    const stack = new Stack();
    stack.push(1);
    expect(stack.pop()).toBe(1);
});

Conclusion

Baby Steps in TDD is not just a technique—it's a mindset that helps developers create better software through careful, incremental changes. By taking small steps, we can build complex systems with confidence and clarity.

"The key to making a program work is to make it small enough that you can understand it." - Kent Beck