Test Helpers - 🌲 Sonamu

Learn how to efficiently manage test data using Sonamu’s Fixture system.

Test Helpers Overview

Fixture Loader

Test data reuse Type-safe loading

Fixture Manager

Copy data between DBs Auto relationship handling

Easy Setup

Define once Share across tests

Auto Cleanup

Transaction based Auto rollback

Fixture Loader

createFixtureLoader

Pre-define fixtures for tests and load when needed.

// api/src/testing/fixture.ts
import { createFixtureLoader } from "sonamu/test";
import { UserModel } from "@/models/user.model";
import { PostModel } from "@/models/post.model";

export const loadFixtures = createFixtureLoader({
  // User fixtures
  user01: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "john",
      email: "john@example.com",
      password: "password123",
    });
    return user;
  },

  user02: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "jane",
      email: "jane@example.com",
      password: "password456",
    });
    return user;
  },

  admin: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "admin",
      email: "admin@example.com",
      password: "admin123",
      role: "admin",
    });
    return user;
  },

  // Post fixtures
  post01: async () => {
    const postModel = new PostModel();
    const { post } = await postModel.create({
      title: "First Post",
      content: "Content of first post",
      author_id: 1,
    });
    return post;
  },
});

Using in Tests

// api/src/models/post.model.test.ts
import { bootstrap, test } from "sonamu/test";
import { expect, vi } from "vitest";
import { PostModel } from "./post.model";
import { loadFixtures } from "@/testing/fixture";

bootstrap(vi);

test("Get user's posts", async () => {
  // Load fixtures
  const { user01, post01 } = await loadFixtures(["user01", "post01"]);

  // Test
  const postModel = new PostModel();
  const { posts } = await postModel.getPostsByUser(user01.id);

  expect(posts).toHaveLength(1);
  expect(posts[0].id).toBe(post01.id);
});

test("Admin permission test", async () => {
  // Load only needed fixtures
  const { admin } = await loadFixtures(["admin"]);

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

Benefits

Type safety:

// ✅ Type safe: IDE provides auto-completion
const { user01 } = await loadFixtures(["user01"]);
user01.username; // string

// ❌ Non-existent fixture
const { user999 } = await loadFixtures(["user999"]); // Type error!

Reusability:

// Use same fixture in multiple tests
test("Test 1", async () => {
  const { user01 } = await loadFixtures(["user01"]);
  // ...
});

test("Test 2", async () => {
  const { user01 } = await loadFixtures(["user01"]);
  // ...
});

Selective loading:

// Load only what's needed
const { user01, user02 } = await loadFixtures(["user01", "user02"]);

// admin not loaded → Save creation cost

Complex Fixture Patterns

Fixtures with Relationships

// api/src/testing/fixture.ts
export const loadFixtures = createFixtureLoader({
  author: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "author",
      email: "author@example.com",
      password: "password",
    });
    return user;
  },

  authorPost: async () => {
    // Load author fixture first
    const { author } = await loadFixtures(["author"]);

    const postModel = new PostModel();
    const { post } = await postModel.create({
      title: "Author's Post",
      content: "Content",
      author_id: author.id, // Set relationship
    });
    return post;
  },
});

// Using in test
test("Author and post relationship", async () => {
  const { author, authorPost } = await loadFixtures(["author", "authorPost"]);

  expect(authorPost.author_id).toBe(author.id);
});

Dynamic Fixtures

// api/src/testing/fixture.ts
export const loadFixtures = createFixtureLoader({
  // Fixture that takes parameters
  userWithEmail: async (email: string) => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: email.split("@")[0],
      email,
      password: "password",
    });
    return user;
  },

  // Create multiple data
  users10: async () => {
    const userModel = new UserModel();
    const users = [];

    for (let i = 1; i <= 10; i++) {
      const { user } = await userModel.create({
        username: `user${i}`,
        email: `user${i}@example.com`,
        password: "password",
      });
      users.push(user);
    }

    return users;
  },
});

Fixture Manager

Overview

FixtureManager provides functionality to copy real data from production DB to test DB. Key features:

Extract data from Production → Fixture DB
Sync Fixture DB → Test DB
Auto relationship resolution (BelongsTo, HasMany, ManyToMany)
Duplicate data handling

DB sync

Sync Fixture DB data to Test DB.

// api/src/application/sonamu.ts
import { FixtureManager } from "sonamu/test";

// Fixture DB → Test DB sync
await FixtureManager.sync();

Execution process:

Initialize Test DB (delete existing data)
Fixture DB dump (pg_dump)
Restore to Test DB (pg_restore)

importFixture

Import specific data from Production DB to Fixture DB.

import { FixtureManager } from "sonamu/test";

// Initialize
FixtureManager.init();

// Import User ID 1, 2, 3 to Fixture DB
await FixtureManager.importFixture("User", [1, 2, 3]);

// Auto import all related data (Posts, Comments, etc.)

Auto relationship resolution:

// Even if only User ID 1 requested...
await FixtureManager.importFixture("User", [1]);

// Auto imports:
// - User #1
// - User #1's Profile (OneToOne)
// - User #1's Posts (HasMany)
// - Post's Comments (HasMany)
// - Comment's Author (BelongsTo)

Practical Examples

Basic Fixture Pattern

// api/src/testing/fixture.ts
import { createFixtureLoader } from "sonamu/test";
import { UserModel } from "@/models/user.model";
import { PostModel } from "@/models/post.model";

export const loadFixtures = createFixtureLoader({
  // 1. Simple data
  guestUser: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "guest",
      email: "guest@example.com",
      password: "password",
      role: "guest",
    });
    return user;
  },

  // 2. Multiple data
  testUsers: async () => {
    const userModel = new UserModel();
    const users = await Promise.all([
      userModel.create({
        username: "user1",
        email: "user1@example.com",
        password: "password",
      }),
      userModel.create({
        username: "user2",
        email: "user2@example.com",
        password: "password",
      }),
    ]);
    return users.map(({ user }) => user);
  },

  // 3. Data with relationships
  userWithPosts: async () => {
    const userModel = new UserModel();
    const postModel = new PostModel();

    const { user } = await userModel.create({
      username: "blogger",
      email: "blogger@example.com",
      password: "password",
    });

    const posts = await Promise.all([
      postModel.create({
        title: "Post 1",
        content: "Content 1",
        author_id: user.id,
      }),
      postModel.create({
        title: "Post 2",
        content: "Content 2",
        author_id: user.id,
      }),
    ]);

    return {
      user,
      posts: posts.map(({ post }) => post),
    };
  },
});

Complex Scenario

// api/src/models/comment.model.test.ts
import { bootstrap, test } from "sonamu/test";
import { expect, vi } from "vitest";
import { CommentModel } from "./comment.model";
import { loadFixtures } from "@/testing/fixture";

bootstrap(vi);

test("Create and retrieve comments", async () => {
  // Load needed fixtures
  const { userWithPosts } = await loadFixtures(["userWithPosts"]);
  const { user, posts } = userWithPosts;

  const commentModel = new CommentModel();

  // Create comment
  const { comment } = await commentModel.create({
    content: "Great post!",
    post_id: posts[0].id,
    author_id: user.id,
  });

  // Get comments
  const { comments } = await commentModel.getCommentsByPost(posts[0].id);

  expect(comments).toHaveLength(1);
  expect(comments[0].content).toBe("Great post!");
  expect(comments[0].author_id).toBe(user.id);
});

Best Practices

1. Fixture Naming Convention

// ✅ Correct: Clear names
export const loadFixtures = createFixtureLoader({
  adminUser: async () => {
    /* ... */
  },
  guestUser: async () => {
    /* ... */
  },
  publishedPost: async () => {
    /* ... */
  },
  draftPost: async () => {
    /* ... */
  },
});

// ❌ Wrong: Unclear names
export const loadFixtures = createFixtureLoader({
  user1: async () => {
    /* ... */
  },
  user2: async () => {
    /* ... */
  },
  post1: async () => {
    /* ... */
  },
});

2. Minimal Data

// ✅ Correct: Only needed fields
export const loadFixtures = createFixtureLoader({
  basicUser: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "user",
      email: "user@example.com",
      password: "password",
    });
    return user;
  },
});

// ❌ Wrong: Unnecessary fields
export const loadFixtures = createFixtureLoader({
  complexUser: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "user",
      email: "user@example.com",
      password: "password",
      bio: "Long bio...",
      avatar: "https://...",
      preferences: {
        /* ... */
      },
      // ... too many fields
    });
    return user;
  },
});

3. Fixture Reuse

// ✅ Correct: Reuse in other fixtures
export const loadFixtures = createFixtureLoader({
  user: async () => {
    const userModel = new UserModel();
    const { user } = await userModel.create({
      username: "user",
      email: "user@example.com",
      password: "password",
    });
    return user;
  },

  userPost: async () => {
    const { user } = await loadFixtures(["user"]);
    const postModel = new PostModel();
    const { post } = await postModel.create({
      title: "Post",
      content: "Content",
      author_id: user.id,
    });
    return post;
  },
});

Cautions

Cautions when using Fixtures: 1. Transaction based: Auto rollback for each test 2. Minimal data: Create only minimum data needed for tests 3. Independence: Each test should run independently 4. Type safety: Ensure type safety with createFixtureLoader 5. Clear names: Fixture names should clearly express purpose

Next Steps

Test Structure

bootstrap, test, testAs

Test Scaffolding

Auto test generation

Model System

Understanding Models

Vitest Docs

Vitest guide

Get Started

Core Concepts

Database

API Development

Frontend Integration

Testing

Advanced Features

Tools & CLI

Configuration

API Reference

Troubleshooting

FAQ

​Test Helpers Overview

Fixture Loader

Fixture Manager

Easy Setup

Auto Cleanup

​Fixture Loader

​createFixtureLoader

​Using in Tests

​Benefits

​Complex Fixture Patterns

​Fixtures with Relationships

​Dynamic Fixtures

​Fixture Manager

​Overview

​DB sync

​importFixture

​Practical Examples

​Basic Fixture Pattern

​Complex Scenario

​Best Practices

​1. Fixture Naming Convention

​2. Minimal Data

​3. Fixture Reuse

​Cautions

​Next Steps

Test Structure

Test Scaffolding

Model System

Vitest Docs

Test Helpers Overview

Fixture Loader

createFixtureLoader

Using in Tests

Benefits

Complex Fixture Patterns

Fixtures with Relationships

Dynamic Fixtures

Fixture Manager

Overview

DB sync

importFixture

Practical Examples

Basic Fixture Pattern

Complex Scenario

Best Practices

1. Fixture Naming Convention

2. Minimal Data

3. Fixture Reuse

Cautions

Next Steps