Tips for Beginners

Essential Tips for Using Fixture Monkey #

1. Use Type-Safe Methods #

• Prefer type-safe methods over string-based ones
• Example:

// Instead of
.set("price", 1000L)

// Use
.set(javaGetter(Product::getPrice), 1000L)

2. Use Meaningful Test Data #

• Use values that make sense in your test context
• Avoid using arbitrary values like “test” or “123”
• Consider business rules and constraints when setting values
• Benefits:
  • Makes tests more readable and self-documenting
  • Helps identify test failures more quickly
  • Makes it easier to understand test scenarios
  • Reduces the need for additional comments
• Example:

// Use meaningful values
Product product = fixtureMonkey.giveMeBuilder(Product.class)
    .set("price", 1000L)    // Use realistic price that matches business rules
    .set("name", "Premium Product")  // Use descriptive name that indicates product type
    .set("category", "ELECTRONICS")  // Use valid category from your domain
    .set("stock", 50)       // Use reasonable stock quantity
    .sample();

3. Keep Tests Readable #

• Add comments to explain why specific values are set
• Example:

Product product = fixtureMonkey.giveMeBuilder(Product.class)
    .set("price", 2000L)    // Price above discount threshold
    .set("category", "PREMIUM")  // Category that gets special treatment
    .sample();

4. Handle Collections Properly #

• Set collection size before accessing specific indices
• Example:

Product product = fixtureMonkey.giveMeBuilder(Product.class)
    .size("options", 3)          // Set size first
    .set("options[1]", "red")    // Then access specific index
    .sample();

5. Reuse FixtureMonkey Instance #

• Create one instance and reuse it across tests
• Example:

public class ProductTest {
    private static final FixtureMonkey FIXTURE_MONKEY = FixtureMonkey.builder()
        .objectIntrospector(ConstructorPropertiesArbitraryIntrospector.INSTANCE)
        .build();

    @Test
    void test1() {
        Product product = FIXTURE_MONKEY.giveMeBuilder(Product.class).sample();
        // ...
    }

    @Test
    void test2() {
        Product product = FIXTURE_MONKEY.giveMeBuilder(Product.class).sample();
        // ...
    }
}

6. Reuse ArbitraryBuilder #

• Reuse ArbitraryBuilder instances to maintain consistent test data structure
• Share common configurations across multiple tests
• Improve code readability by centralizing test data setup
• Example:

public class ProductTest {
    private static final FixtureMonkey FIXTURE_MONKEY = FixtureMonkey.builder()
        .objectIntrospector(ConstructorPropertiesArbitraryIntrospector.INSTANCE)
        .build();
    
    // Base configuration for premium products
    private static final ArbitraryBuilder<Product> PREMIUM_PRODUCT_BUILDER = FIXTURE_MONKEY.giveMeBuilder(Product.class)
        .set("category", "PREMIUM")
        .set("price", 1000L);

    @Test
    void testDiscountForPremiumProduct() {
        // Test discount for premium product with price above threshold
        Product product = PREMIUM_PRODUCT_BUILDER
            .set("price", 2000L)  // Price above discount threshold
            .sample();
        // Test discount logic
    }

    @Test
    void testShippingForPremiumProduct() {
        // Test shipping for premium product with minimum order amount
        Product product = PREMIUM_PRODUCT_BUILDER
            .set("price", 5000L)  // Price above free shipping threshold
            .sample();
        // Test shipping logic
    }
}

7. Start with Simple Objects #

• Begin with basic objects before moving to complex ones
• Example:

public class ProductTest {
    private static final FixtureMonkey FIXTURE_MONKEY = FixtureMonkey.builder()
        .objectIntrospector(ConstructorPropertiesArbitraryIntrospector.INSTANCE)
        .build();

    @Test
    void testBasicProduct() {
        // Start with a simple object
        Product product = FIXTURE_MONKEY.giveMeBuilder(Product.class)
            .set("name", "Test Product")
            .sample();
        // ...
    }
}

8. Use the IntelliJ Plugin #

Install the Fixture Monkey Helper plugin to enhance your development experience:

• Smart code completion for Fixture Monkey methods
• Type-safe field access suggestions using method references
• Quick navigation to field definitions
• Automatic import suggestions for Fixture Monkey classes
• Real-time validation of field names and types

9. Common Use Cases #

• Testing validation rules
• Testing business logic with specific conditions
• Creating test data for integration tests
• Generating random but valid test data

10. Best Practices #

• Keep test data generation close to where it’s used
• Use meaningful variable names
• Document complex test scenarios
• Use constants for frequently used values