vitest-environment-vprisma

vitest-environment-vprisma

This library improves the experience of testing with vitest and @prisma/client. It allows you to isolate each test case with a transaction and rollback after completion, giving you a safe and clean testing environment.

Install

$ npm install -D vitest-environment-vprisma

Setup

// vitest.config.ts
import { defineConfig } from "vite";

export default defineConfig({
  test: {
    globals: true,  // Don't forget!
    environment: "vprisma",
    setupFiles: ["vitest-environment-vprisma/setup"]
  },
});

// tsconfig.json
{
  "compilerOptions": {
    "types": ["vitest/globals", "vitest-environment-vprisma"]
  }
}

How to use

If you are using an instance of PrismaClient in your test file to issue queries, use vPrisma.client instead. If setup is correct, it will be provided as a global object.

// example.test.ts

// Use `vPrisma.client` instead of `const prisma = new PrismaClient()`.
const prisma = vPrisma.client;

test("Add user", async () => {
  const createdUser = await prisma.user.create({
    data: {
      nickname: "user1",
      email: "[e-mail]",
    },
  });

  expect(
    await prisma.user.findFirst({
      where: {
        id: createdUser.id,
      },
    })
  ).toStrictEqual(createdUser);
  expect(await prisma.user.count()).toBe(1);
});

// Each test case is isolated in a transaction and also rolled back, so it is not affected by another test result.
test("Count user", async () => {
  expect(await prisma.user.count()).toBe(0);
});

Please check this sample.

Singleton

If you are using an instance of PrismaClient as a singleton, such as:

// libs/client.ts
import { PrismaClient } from "@prisma/client";

export const client = new PrismaClient();

// libs/user.ts
import { client } from "./client";

export const createUser = (nickname: string, email: string) => {
  return client.user.create({
    data: {
      nickname,
      email,
    },
  });
};

It is easier to test if it is mocked up in the vitest setup file.

// vitest.config.ts
import { defineConfig } from "vite";

export default defineConfig({
  test: {
    globals: true,
    environment: "vprisma",
    setupFiles: ["vitest-environment-vprisma/setup", "vitest.setup.ts"] // add vitest.setup.ts
  },
});

// vitest.setup.ts
import { vi } from "vitest";

vi.mock("./libs/client", () => ({
  client: vPrisma.client,
}));

Options

It is possible to pass option values using environmentOptions. This affects the entire test.

// vitest.config.ts
import { defineConfig } from "vite";

export default defineConfig({
  test: {
    globals: true,
    environment: "vprisma",
    setupFiles: ["vitest-environment-vprisma/setup"],
    environmentOptions: {
      vprisma: {
        // Selectable a base environment "node" | "jsdom" | "happy-dom" | "edge-runtime" (default: "node") 
        baseEnv: "jsdom",
        // Display the query in the log. (default: false)
        verboseQuery: true,
        // Commit without rolling back the transaction. (default: false)
        disableRollback: true,
        // Override the database connection URL. (default: process.env.DATABASE_URL)
        databaseUrl: "postgresql://postgres:password@localhost:5432/test?schema=public"
      }
    },
  },
});

It is also possible to specify these option values for each test file.
Use the format // @vitest-environment-options { "key": "value" }. Option values are in JSON format.

// example.test.ts

// @vitest-environment-options { "verboseQuery": true }
test("Add user", async () => {
  /* ... */
});

Note that any environmentOptions set in vitest.config.ts will be overwritten.

Tips

hooks (beforeEach and beforeAll)

You cannot use vPrisma.client within a top-level beforeEach. This is because it is executed before the vPrisma initialization is complete.
If you want to use beforeEach to perform data preparation or other operations, please write them within describe.

const prisma = vPrisma.client;

beforeEach(async () => {
  // ❌ vPrisma.client is not available for top-level beforeEach.
});

describe(" ... ", () => {
  beforeEach(async () => {
    // ✅ You can use vPrisma.client.
    await prisma.user.create({
      data: {
        nickname: "userX",
        email: "[e-mail]",
      },
    });
  });
  
  test(" ... ", () => {
    /* ... */
  });
});

Unfortunately, it is not possible to use vPrisma.client within beforeAll (either at the top level or within describe).
This is because the transaction is initiated in beforeEach and rolled back in afterEach. beforeAll is executed outside of its life cycle.

Acknowledgments

This library is based on @quramy/jest-prisma. We would like to express our great appreciation to @quramy/jest-prisma's owner, @Quramy, and contributors.

License

This project is licensed under the MIT License - see the LICENSE file for details