Testing Fixtures

Testing Fixtures

Overview

Test fixtures provide the known, fixed state needed to run tests. They include static test data, factory classes that generate dynamic data, and fixture files for shared data across tests. Good fixture management keeps tests isolated, readable, and maintainable.

Language Mode Reference

Examples use BoxLang (.bx) syntax by default. Adapt for your target language:

CFML Compat Mode: With BoxLang + CFML Compat module, .bx and .cfc files coexist freely. BoxLang-native classes use class {} (.bx files); CFML-compat classes use component {} (.cfc files).

Static Inline Fixtures

describe( "User validation", () => {

    it( "should validate valid user data", () => {
        validUser = {
            name: "John Doe",
            email: "john@example.com",
            age: 30,
            active: true
        }

        result = userValidator.validate( validUser )
        expect( result.isValid ).toBeTrue()
    } )

    it( "should reject invalid email", () => {
        invalidUser = {
            name: "John Doe",
            email: "not-an-email",
            age: 30
        }

        result = userValidator.validate( invalidUser )
        expect( result.isValid ).toBeFalse()
        expect( result.errors ).toHaveKey( "email" )
    } )
} )

Shared Fixture Variables

describe( "User operations", () => {

    // Define shared test data at describe scope
    variables.validUserData = {
        name: "John Doe",
        email: "john@example.com",
        password: "SecurePass123!",
        age: 30
    }

    beforeEach( () => {
        // Create a fresh copy for each test to prevent mutation
        variables.testUser = duplicate( validUserData )
    } )

    it( "should create user with valid data", () => {
        user = userService.create( testUser )
        expect( user.id ).toBeNumeric()
    } )

    it( "should update user name", () => {
        user = userService.create( testUser )
        testUser.name = "Jane Doe"

        updated = userService.update( user.id, testUser )
        expect( updated.name ).toBe( "Jane Doe" )
    } )
} )

Fixture File Pattern

/**
 * tests/fixtures/UserFixtures.cfc
 * Centralized test data for user-related tests
 */
component {

    function getValidUser() {
        return {
            name: "John Doe",
            email: "john@example.com",
            password: "SecurePass123!",
            age: 30,
            active: true
        }
    }

    function getAdminUser() {
        return getValidUser().append( {
            email: "admin@example.com",
            role: "admin",
            permissions: [ "read", "write", "delete" ]
        }, true )
    }

    function getInvalidUsers() {
        return [
            { name: "", email: "john@example.com", _errorField: "name" },
            { name: "John", email: "invalid-email", _errorField: "email" },
            { name: "John", email: "john@example.com", age: -5, _errorField: "age" }
        ]
    }

    function getUsers( required numeric count = 5 ) {
        users = []

        for ( i = 1; i <= count; i++ ) {
            users.append( {
                name: "User ##i##",
                email: "user##i##@example.com",
                age: 20 + i
            } )
        }

        return users
    }
}

Using fixture file:

component extends="testbox.system.BaseSpec" {

    function run() {
        describe( "User service with fixture file", () => {

            beforeAll( () => {
                variables.fixtures    = new tests.fixtures.UserFixtures()
                variables.userService = getInstance( "UserService" )
            } )

            it( "should create valid user", () => {
                userData = fixtures.getValidUser()
                user     = userService.create( userData )

                expect( user.id ).toBeNumeric()
                expect( user.name ).toBe( userData.name )
            } )

            it( "should reject all invalid formats", () => {
                for ( invalidUser in fixtures.getInvalidUsers() ) {
                    result = userService.validate( invalidUser )
                    expect( result.isValid ).toBeFalse()
                    expect( result.errors ).toHaveKey( invalidUser._errorField )
                }
            } )
        } )
    }
}

Factory Pattern

/**
 * tests/factories/UserFactory.cfc
 * Dynamic test data factory with sequence counter
 */
component singleton {

    variables.counter = 0

    function create( struct overrides = {} ) {
        variables.counter++

        defaults = {
            name:        "Test User ##counter##",
            email:       "testuser##counter##@example.com",
            password:    "Password##counter##!",
            age:         20 + counter,
            active:      true,
            createdDate: now()
        }

        return structAppend( defaults, overrides, true )
    }

    function createMany( required numeric count, struct overrides = {} ) {
        return listToArray( repeatString( ",", count - 1 ) )
            .map( () => create( overrides ) )
    }

    function createAdmin( struct overrides = {} ) {
        return create( {
            role: "admin",
            permissions: [ "read", "write", "delete" ]
        }.append( overrides, true ) )
    }

    function createInactive( struct overrides = {} ) {
        return create( { active: false }.append( overrides, true ) )
    }

    function reset() {
        variables.counter = 0
    }
}

Using factory:

component extends="testbox.system.BaseSpec" {

    function run() {
        describe( "With factory", () => {

            beforeAll( () => {
                variables.factory     = new tests.factories.UserFactory()
                variables.userService = getInstance( "UserService" )
            } )

            beforeEach( () => {
                factory.reset()
            } )

            it( "should process multiple users", () => {
                // Create 3 test users
                users = factory.createMany( 3 )
                    .map( u => userService.create( u ) )

                expect( users ).toHaveLength( 3 )
                expect( users[1].name ).toBe( "Test User 1" )
            } )

            it( "should grant admin privileges", () => {
                admin = factory.createAdmin( { email: "customadmin@test.com" } )
                user  = userService.create( admin )

                expect( user.role ).toBe( "admin" )
            } )
        } )
    }
}

Using cbMockData for Realistic Fake Data

For the full cbMockData type reference, see the testbox-cbmockdata skill.

WireBox ID: MockData@cbMockData

cbMockData is bundled with TestBox — no separate install required.

component extends="testbox.system.BaseSpec" {

    property name="mockData" inject="MockData@cbMockData"

    function run() {
        describe( "With cbMockData", () => {

            it( "should generate a realistic user", () => {
                var userData = mockData.mock(
                    $returnType: "struct",
                    firstName:   "fname",
                    lastName:    "lname",
                    email:       "email",
                    age:         "age",
                    bio:         "sentence"
                )

                expect( userData.firstName ).toBeString()
                expect( userData.email ).toMatch( ".+@.+" )
                expect( userData.age ).toBeNumeric()
            } )

            it( "should generate a collection of users", () => {
                var users = mockData.mock(
                    $num:   10,
                    id:     "autoincrement",
                    name:   "name",
                    email:  "email",
                    status: "oneof:active:inactive:pending"
                )

                expect( users ).toHaveLength( 10 )
                expect( [ "active", "inactive", "pending" ] ).toInclude( users[ 1 ].status )
            } )

            it( "should generate nested objects", () => {
                var order = mockData.mock(
                    $returnType: "struct",
                    id:          "autoincrement",
                    customerId:  "uuid",
                    total:       "rnd:50:500",
                    items: {
                        $num:  "rnd:1:5",
                        sku:   "uuid",
                        name:  "words",
                        price: "rnd:5:100"
                    }
                )

                expect( order ).toHaveKey( "items" )
                expect( order.items ).toBeArray()
            } )

        } )
    }
}

Database Seeder Pattern

/**
 * tests/fixtures/DatabaseSeeder.cfc
 */
component singleton {

    function seedUsers( required numeric count = 5 ) {
        factory = new tests.factories.UserFactory()
        users = []

        for ( i = 1; i <= count; i++ ) {
            data = factory.create()
            qry = queryExecute(
                "INSERT INTO users (name, email) VALUES (:name, :email)",
                { name: data.name, email: data.email },
                { datasource: "testdb" }
            )
            data.id = qry.generatedKey
            users.append( data )
        }

        return users
    }

    function cleanup() {
        queryExecute( "DELETE FROM users WHERE email LIKE 'testuser%@example.com'", {}, { datasource: "testdb" } )
    }
}

Best Practices

1. Always duplicate() shared fixture data before mutating in tests to prevent cross-test contamination
2. Use factories for dynamic, unique data — avoids duplicate key violations
3. Use fixture files for complex, reusable test data sets
4. Keep fixtures minimal — only include fields the test actually needs
5. Reset factory counters in beforeEach for predictable sequences
6. Namespace test emails — use testuser@example.com pattern for easy cleanup