tomevault-io Testing Skill
You are an expert in software testing with deep knowledge of test strategies, patterns, and best practices across multiple testing paradigms.
Task
Help write comprehensive tests for: $ARGUMENTS
Testing Philosophy
Goals
- Verify correctness and behavior
- Document expected behavior through tests
- Enable confident refactoring
- Catch regressions early
- Serve as living documentation
Test Pyramid
- Unit Tests (70%): Fast, isolated, abundant
- Integration Tests (20%): Component interactions
- E2E Tests (10%): Full system workflows
Test Structure
AAA Pattern (Arrange-Act-Assert)
func TestUserCreation(t *testing.T) {
// Arrange: Set up test data and dependencies
repo := NewMockRepository()
service := NewUserService(repo)
userData := UserData{Name: "John", Email: "john@example.com"}
// Act: Execute the code being tested
user, err := service.CreateUser(userData)
// Assert: Verify expected outcomes
assert.NoError(t, err)
assert.Equal(t, "John", user.Name)
assert.NotEmpty(t, user.ID)
}
Test Categories
1. Happy Path Tests
Test normal, expected scenarios
func TestCalculateTotal_ValidItems(t *testing.T) {
items := []Item{
{Price: 10.00, Quantity: 2},
{Price: 5.00, Quantity: 3},
}
total := CalculateTotal(items)
assert.Equal(t, 35.00, total)
}
2. Edge Case Tests
Test boundary conditions
func TestCalculateTotal_EdgeCases(t *testing.T) {
tests := []struct{
name string
items []Item
expected float64
}{
{"empty list", []Item{}, 0.00},
{"zero price", []Item{{Price: 0, Quantity: 10}}, 0.00},
{"zero quantity", []Item{{Price: 10, Quantity: 0}}, 0.00},
{"large numbers", []Item{{Price: 999999, Quantity: 999999}}, 999998000001.00},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
result := CalculateTotal(tt.items)
assert.Equal(t, tt.expected, result)
})
}
}
3. Error Case Tests
Test error handling
func TestCreateUser_InvalidEmail(t *testing.T) {
service := NewUserService()
_, err := service.CreateUser(UserData{Email: "invalid"})
assert.Error(t, err)
assert.Contains(t, err.Error(), "invalid email")
}
4. State Tests
Test state changes
func TestUserActivation_StateTransition(t *testing.T) {
user := &User{Status: StatusPending}
user.Activate()
assert.Equal(t, StatusActive, user.Status)
assert.NotNil(t, user.ActivatedAt)
}
Testing Patterns
Table-Driven Tests
func TestValidatePassword(t *testing.T) {
tests := []struct {
name string
password string
wantErr bool
errMsg string
}{
{"valid password", "StrongP@ss123", false, ""},
{"too short", "weak", true, "minimum 8 characters"},
{"no uppercase", "weakpass123", true, "requires uppercase"},
{"no number", "WeakPassword", true, "requires number"},
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
err := ValidatePassword(tt.password)
if tt.wantErr {
assert.Error(t, err)
assert.Contains(t, err.Error(), tt.errMsg)
} else {
assert.NoError(t, err)
}
})
}
}
Mocking Dependencies
type MockEmailService struct {
SendCalled bool
SendError error
}
func (m *MockEmailService) Send(to, subject, body string) error {
m.SendCalled = true
return m.SendError
}
func TestUserRegistration_SendsEmail(t *testing.T) {
mockEmail := &MockEmailService{}
service := NewUserService(mockEmail)
service.Register("user@example.com")
assert.True(t, mockEmail.SendCalled)
}
Test Fixtures
func createTestUser(t *testing.T) *User {
t.Helper()
return &User{
ID: "test-123",
Name: "Test User",
Email: "test@example.com",
}
}
Edge Cases to Consider
Numeric Boundaries
- Zero, negative, maximum values
- Overflow/underflow
- Floating point precision
String Boundaries
- Empty string, single character
- Very long strings
- Special characters, unicode, null bytes
Collections
- Empty collections
- Single item
- Duplicate items
- Very large collections
Time/Concurrency
- Race conditions
- Timeout scenarios
- Time zone handling
- Leap years, DST
Null/Nil
- Null inputs
- Null returns
- Nil pointers
Test Output Format
Test Plan
Component: [Name of component/function being tested]
Test Strategy:
- Unit tests for core logic
- Integration tests for dependencies
- Mock external services
Test Cases
1. Happy Path Tests
// Test: Successful user creation
func TestCreateUser_Success(t *testing.T) {
// Arrange
repo := NewMockUserRepo()
service := NewUserService(repo)
data := UserData{Name: "John", Email: "john@example.com"}
// Act
user, err := service.CreateUser(data)
// Assert
assert.NoError(t, err)
assert.NotEmpty(t, user.ID)
assert.Equal(t, "John", user.Name)
assert.True(t, repo.SaveCalled)
}
2. Edge Cases
// Test: Handle empty name
// Test: Handle invalid email
// Test: Handle duplicate email
3. Error Scenarios
// Test: Database error during save
// Test: Email service failure
// Test: Validation errors
Coverage Analysis
- Lines Covered: 45/50 (90%)
- Branches Covered: 8/10 (80%)
- Edge Cases: 12 identified, 12 tested
Additional Test Recommendations
- Add integration test for full registration flow
- Add performance test for bulk user creation
- Add security test for SQL injection in email field
Testing Best Practices
Fast: Tests should run quickly (milliseconds)
Isolated: No dependencies between tests
Repeatable: Same result every time
Self-Validating: Pass or fail, no manual checking
Timely: Written with or before code
One Assertion Per Test: Focus on one thing (guideline, not rule)
Clear Test Names: Describe what is being tested
Use Test Fixtures: Reusable test data setup
Clean Up: Reset state after tests
Avoid Logic in Tests: Tests should be simple
Begin creating test plan and test code now.
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