gem-hunter
Language: TypeScript
Simple factories with faker data based on zod schemas
A factory is a function that generates mock data based on a given schema. It's a powerful tool for developers, offering:
• 🧪 Easy generation of test data for your application
• 🔄 Consistent and reproducible mock data creation
• 📊 Support for complex, nested schemas
• 🎭 Flexible customization of generated data
• ⚡ Improved development speed and efficiency
• 🐞 Enhanced testing capabilities for edge cases
import { z } from 'npm:zod@v3.23.8'; import { faker } from 'npm:@faker-js/faker@8.4.1'; import { factory } from 'jsr:@findhow/zod-factory@0.0.2'; const UserSchema = z.object({ id: z.string().uuid(), name: z.string(), email: z.string().email(), age: z.number().int().positive() }); const UserFactory = factory(UserSchema, (faker) => ({ id: faker.string.uuid(), name: faker.person.fullName(), email: faker.internet.email(), age: faker.number.int({ min: 18, max: 99 }) })); UserFactory.create(); UserFactory.create({ name: 'John Doe' }); UserFactory.createMany(10); UserFactory.createMany(3, { age: 25, email: faker.internet.email() })
https://deno.land/x/zod@v3.23.8/mod.ts
https://esm.sh/@faker-js/faker@8.4.1
First, we'll define a simple schema using Zod for a user profile:
import { z } from 'npm:zod@v3.23.8'; // Define a simple Zod schema for a user profile export const UserSchema = z.object({ id: z.string().uuid(), // Unique identifier for the user name: z.string(), // User's name email: z.string().email(), // User's email age: z.number().int().positive() // User's age });
Now we'll define a simple factory using the
factoryfunction and theUserSchemawe just created:
import { factory } from 'jsr:@findhow/zod-factory@0.0.2'; import { UserSchema } from './user.schema.ts' export const UserFactory = factory(UserSchema, (faker) => ({ id: faker.string.uuid(), name: faker.person.fullName(), email: faker.internet.email(), age: faker.number.int({ min: 18, max: 99 }) }));
Then we'll use the factory to generate mock data:
import { UserFactory } from "./user.factory.ts" console.log(UserFactory.create());
Outputs (random values will be generated each time)
{
id: 'd81b154e-4fa4-11ec-81d3-0242ac130003',
name: 'Jane Doe',
email: 'jane.doe@example.com',
age: 34
}
We can also create multiple users
const users = UserFactory.createMany(2); console.log(users);
Outputs (random values will be generated each time)
[
{
id: 'd81b154e-4fa4-11ec-81d3-0242ac130003',
name: 'Jane Doe',
email: 'jane.doe@example.com',
age: 34
},
{
id: 'd81b154e-4fa4-11ec-81d3-0242ac130003',
name: 'John Don',
email: 'John.don@example.com',
age: 31
}
]
If you need to override a single or multiple properties to be deterministic, you can pass in an object to the
createmethod:
const customUser = UserFactory.create({ name: 'John Doe', email: 'john.doe@example.com', age: 25 }); console.log(customUser);
Outputs (random values will be generated each time)
{
id: 'd81b154e-4fa4-11ec-81d3-0242ac130003',
name: 'John Doe',
email: 'john.doe@example.com',
age: 25
}
We can also create many users with specific attributes
const customUsers = UserFactory.createMany(3, { age: 25 }) console.log(customUsers)
outputs (random values will be generated each time accept for age which is set to 25)
[
{
id: 'abc1b154e-4fa4-11ec-81d3-0242ac130024',
name: 'Timmy Bob',
email: 'timmy.bob@example.com',
age: 25
},
{
id: 'd81b154e-4fa4-11ec-81d3-0242ac130003',
name: 'John Doe',
email: 'john.doe@example.com',
age: 25
},
{
id: 'aa2b154e-4fa4-11ec-81d3-0242ac130003',
name: 'Sarah Black',
email: 'sarah.black@example.com',
age: 25
},
]
UserSchema: Defines the shape of our user data, specifying the types and constraints.UserFactory: Uses the faker library to dynamically generate mock data conforming to UserSchema.create and createMany: Methods to generate one or many instances of user data.attributes: An optional parameter to override generated values for a single or multiple properties to be deterministic.Let's create a
ComplexUserFactoryfor generating mock data based on a deeply nested schema. This will demonstrate how to handle nested objects and arrays while still utilizing thefakercallback for dynamic data generation.
We'll define a more complex schema with nested objects and arrays:
import { z } from 'https://deno.land/x/zod@v3.23.8/mod.ts'; // Define a deeply nested Zod schema for a complex user profile const ComplexUserSchema = z.object({ id: z.string().uuid(), // Unique identifier for the user profile: z.object({ // Nested profile object name: z.string(), // User's name email: z.string().email(), // User's email bio: z.string().optional(), // Optional bio for the user socialMedia: z.array(z.object({ // Array of nested social media accounts platform: z.enum(['twitter', 'facebook', 'instagram']), // Enum for social media platform username: z.string(), // Username for the social media account })), }), posts: z.array(z.object({ // Array of nested posts title: z.string(), // Title of the post content: z.string(), // Content of the post tags: z.array(z.string()), // Array of tags for the post publishedAt: z.date(), // Date when the post was published })), settings: z.object({ // Nested settings object theme: z.enum(['light', 'dark']), // User interface theme preference notifications: z.boolean(), // Boolean for whether notifications are enabled preferences: z.record(z.string(), z.union([ // Preferences as a record (key-value pairs) z.string(), z.number(), z.boolean(), ])), }), });
import { factory } from './mod.ts'; // Import the factory implementation import { ComplexUserSchema } from './schema.ts'; const ComplexUserFactory = factory(ComplexUserSchema, (faker) => ({ id: faker.string.uuid(), // Generate a random UUID for the user ID profile: { // Generate nested profile data name: faker.person.fullName(), // Generate a random full name email: faker.internet.email(), // Generate a random email address bio: faker.lorem.paragraph(), // Generate a random paragraph for the bio socialMedia: Array.from({ length: faker.number.int({ min: 1, max: 3 }) }, () => ({ // Generate 1-3 social media accounts platform: faker.helpers.arrayElement(['twitter', 'facebook', 'instagram']), // Randomly select a platform username: faker.internet.userName(), // Generate a random username })), }, posts: Array.from({ length: faker.number.int({ min: 1, max: 5 }) }, () => ({ // Generate 1-5 posts title: faker.lorem.sentence(), // Generate a random title content: faker.lorem.paragraphs(), // Generate random content tags: Array.from({ length: faker.number.int({ min: 1, max: 5 }) }, () => faker.lorem.word()), // Generate 1-5 tags publishedAt: faker.date.recent(), // Generate a recent date for publishedAt })), settings: { // Generate settings data theme: faker.helpers.arrayElement(['light', 'dark']), // Randomly select a theme notifications: faker.datatype.boolean(), // Randomly decide if notifications are enabled preferences: Object.fromEntries( // Generate random preferences Array.from({ length: faker.number.int({ min: 1, max: 5 }) }, () => [ faker.lorem.word(), faker.helpers.arrayElement([ faker.lorem.word(), faker.number.int(), faker.datatype.boolean(), ]), ]) ), }, }));
// Create a single complex user mock object const complexUser = ComplexUserFactory.create(); console.log(complexUser); /* Example output: { id: 'd81b154e-4fa4-11ec-81d3-0242ac130003', profile: { name: 'Jane Doe', email: 'jane.doe@example.com', bio: 'Lorem ipsum dolor sit amet...', socialMedia: [ { platform: 'twitter', username: 'janedoe123' } ] }, posts: [ { title: 'My First Post', content: 'Lorem ipsum dolor sit amet...', tags: ['tech', 'deno'], publishedAt: '2024-09-02T12:34:56.789Z' } ], settings: { theme: 'dark', notifications: true, preferences: { newsletter: true, timezone: 'PST' } } } */ // Create multiple complex user mock objects const complexUsers = ComplexUserFactory.createMany(3); console.log(complexUsers); // Outputs an array of 3 complex user objects // Create a complex user with specific attributes const customComplexUser = ComplexUserFactory.create({ profile: { name: 'John Smith', email: 'john.smith@example.com' }, }); console.log(customComplexUser); /* Example output: { id: 'a52b154e-4fa4-11ec-81d3-0242ac130003', profile: { name: 'John Smith', email: 'john.smith@example.com', bio: 'Lorem ipsum dolor sit amet...', socialMedia: [ { platform: 'facebook', username: 'johnsmith' } ] }, posts: [ { title: 'Tech Insights', content: 'Lorem ipsum dolor sit amet...', tags: ['coding', 'deno'], publishedAt: '2024-09-02T12:34:56.789Z' } ], settings: { theme: 'light', notifications: false, preferences: { updates: false, language: 'en' } } } */
In this setup:
profile: A nested object that includes name, email, and bio, along with an array of social media accounts. Each account object is dynamically generated using faker utilities.posts: An array of objects, where each object represents a post with dynamically generated title, content, tags, and publishedAt.settings: A nested object for user settings, including random preferences generated using the faker utility.By using a faker callback with a deeply nested schema, you can effectively create complex mock data structures that conform to your application's requirements. This approach ensures that you have realistic, varied test data for all your testing and development needs.
Factory - basic creation tests ... factory - create ... ok factory - create with custom attributes ... ok factory - createMany ... ok factory - createMany with custom attributes ... ok Factory - basic creation tests ... ok Factory - raw tests ... factory - raw ... ok factory - raw with custom attributes ... ok Factory - raw tests ... ok Factory - state tests ... factory - state ... ok factory - state with faker ... ------- output ------- [@faker-js/faker]: faker.name is deprecated since v8.0 and will be removed in v10.0. Please use faker.person instead. ----- output end ----- factory - state with faker ... ok Factory - state tests ... ok Factory - input validation tests ... factory - handle invalid attribute types ... ok factory - handle missing required attributes ... ok Factory - input validation tests ... ok Factory - performance tests ... factory - performance test for createMany ... ------- output ------- Performance test: createMany(100) took 5908ms ----- output end ----- factory - performance test for createMany ... ok Factory - performance tests ... ok Factory - complex schema tests ... complex factory - create validates against schema ... ok complex factory - create sets default user name ... ok complex factory - create with deep profile override ... complex factory - create with deep profile override ... ok complex factory - create with deep settings override ... complex factory - create with deep settings override ... ok (53ms) complex factory - implement with transform ... ------- output ------- { "street": "95824 Romaguera Loop", "city": "Fort Benny", "state": "AL", "zip": "17806", "county": "Nottinghamshire", "sale_date": "2024-10-03", "sale_time": "4:34:58 AM", "continued_date_time": "N/A", "opening_bid": "$200,000", "sale_location": "New Orin", "firm_file_number": "084439307" } ----- output end ----- complex factory - implement with transform ... ok Factory - complex schema tests ... ok Factory - Randomness and Uniqueness ... complex factory - createMany generates unique IDs ... ok complex factory - createMany generates unique emails ... ok Factory - Randomness and Uniqueness ... ok should generate a mock object using faker ... ok should generate mock data of the appropriate type when the field names overlap Faker properties that are not valid functions ... ok Should manually mock string key names to set values ... ok should convert values produced by Faker to string when the schema type is string. ... ok should support generating date strings via Faker for keys of 'date' and 'dateTime'. ... ok should correctly generate date strings for date validated strings ... ok should create mock strings that respect the specified min and max lengths (inclusive) ... ok should respect the max length when the min is greater than the max ... ok should append extra string content to meet a minimum length ... ok should create mock strings that respect the specified length ... ok should create mock dates that respect the specified min and max dates ... ok should create Maps ... ok should use a user provided generator when a generator for the schema type cannot be found ... ok should use a user provided generator when a generator takes 2 arguments ... ok should work with objects and arrays ... ok should work with the README example ... ok throws an error when configured to if we have not implemented the type mapping ... ok ZodDefault ... ok ZodNativeEnum ... ok ZodFunction ... ok ZodIntersection ... ok ZodPromise ... ok ZodTuple ... basic tuple ... ok tuple with Rest args ... ok ZodTuple ... ok ZodUnion ... ok Avoid depreciations in strings ... ok should generate strings from regex ... ok should handle complex unions ... ok should handle discriminated unions ... ok should handle branded types ... ok ZodVoid ... ok ZodNull ... ok ZodNaN ... ok ZodUndefined ... ok ZodLazy ... ok Options seed value will return the same random numbers ... ok Options seed value will return the same union & enum members ... ok Options seed value will return the same generated regex values ... ok Can use my own version of faker ... ok Will mock sub objections properly ... ok should handle various date constraints correctly ... ok should handle invalid date constraints ... ok should handle JSON type ... ok zod-mock ... ok Potential infinite loop or memory exhaustion tests ... should handle deep recursive structures without stack overflow ... ------- post-test output ------- Generated nested structure with depth: 5 ----- post-test output end ----- should handle deep recursive structures without stack overflow ... ok should handle cyclical references gracefully ... ok Potential infinite loop or memory exhaustion tests ... ok