Can not run multiple tests in a file - testing

Question

I'm building a GraphQL API and I want to test some resolvers and the database with jest.
Here is my helper file, where I set up the context and the Prisma Client for testing.
import { PrismaClient } from "#prisma/client";
import { ServerInfo } from "apollo-server";
import { execSync } from "child_process";
import getPort, { makeRange } from "get-port";
import { GraphQLClient } from "graphql-request";
import { nanoid } from "nanoid";
import { join } from "path";
import { Client } from "pg";
import { server } from "../api/server";
type TestContext = {
client: GraphQLClient;
db: PrismaClient;
};
export function createTestContext(): TestContext {
let ctx = {} as TestContext;
const graphqlCtx = graphqlTestContext();
const prismaCtx = prismaTestContext();
beforeEach(async () => {
const client = await graphqlCtx.before();
const db = await prismaCtx.before();
Object.assign(ctx, {
client,
db,
});
});
afterEach(async () => {
await graphqlCtx.after();
await prismaCtx.after();
});
return ctx;
}
function graphqlTestContext() {
let serverInstance: ServerInfo | null = null;
return {
async before() {
const port = await getPort({ port: makeRange(4000, 6000) });
serverInstance = await server.listen({ port });
return new GraphQLClient(`http://localhost:${port}`);
},
async after() {
serverInstance?.server.close();
},
};
}
function prismaTestContext() {
const prismaBinary = join(__dirname, "..", "node_modules", ".bin", "prisma");
let schema = "";
let databaseUrl = "";
let prismaClient: null | PrismaClient = null;
return {
async before() {
schema = `test_${nanoid()}`;
databaseUrl = `postgresql://user:123#localhost:5432/testing?schema=${schema}`;
process.env.DATABASE_URL = databaseUrl;
execSync(`${prismaBinary} migrate up --create-db --experimental`, {
env: {
...process.env,
DATABASE_URL: databaseUrl,
},
});
prismaClient = new PrismaClient();
return prismaClient;
},
async after() {
const client = new Client({
connectionString: databaseUrl,
});
await client.connect();
await client.query(`DROP SCHEMA IF EXISTS "${schema}" CASCADE`);
await client.end();
await prismaClient?.$disconnect();
},
};
}
My test file looks like this:
import { createTestContext } from "./__helpers";
const ctx = createTestContext();
it("register user", async () => {
const testUser = {
username: "Test",
email: "test#test.com",
password: "password",
};
const registerResult = await ctx.client.request(
`
mutation registerNewUser($username: String!, $email: String!, $password: String!) {
register(username: $username, email: $email, password: $password) {
user {
user_id
username
email
}
}
}
`,
{
username: testUser.username,
email: testUser.email,
password: testUser.password,
}
);
const resultUsername = registerResult.register.user.username;
const resultEmail = registerResult.register.user.email;
const resultUserID = registerResult.register.user.user_id;
expect(resultUsername).toBe(testUser.username);
expect(resultEmail).toBe(testUser.email);
expect(resultUserID).not.toBeNull;
const users = await ctx.db.user.findMany();
const savedUser = users[0];
expect(savedUser.username).toBe(testUser.username);
expect(savedUser.email).toBe(testUser.email);
expect(savedUser.user_id).toBe(resultUserID);
expect(savedUser.first_name).toBeNull;
expect(savedUser.last_name).toBeNull;
expect(savedUser.role).toBe("USER");
expect(savedUser.password).not.toBe(testUser.password);
});
it("all events", async () => {
const eventsResult = await ctx.client.request(
`
query {
allEvents {
event_id
title
description
}
}
`
);
expect(eventsResult.allEvents.length).toBe(0)
});
When I just run one file with one test in it, everything works. But when I run multiple tests in one file, the first one runs normal, but the ones after not. I receive this error:
The table `test_LjrcmbMjI4vLaDYM9-lvw.Event` does not exist in the current database.: {"response":{"errors":[{"message":"\nInvalid `prisma.event.findMany()` invocation:\n\n\n The table `test_LjrcmbMjI4vLaDYM9-lvw.Event` does not exist in the current database.","locations":[{"line":3,"column":7}],"path":["allEvents"],"extensions":{"code":"INTERNAL_SERVER_ERROR","exception":{"code":"P2021","clientVersion":"2.11.0","meta":{"table":"test_LjrcmbMjI4vLaDYM9-lvw.Event"}}}}],"data":null,"status":200},"request":{"query":"\n query {\n allEvents {\n event_id\n title\n description\n }\n }\n "}}
Also when I run two tests in separated files, on every second test run I get this error:
listen EADDRINUSE: address already in use :::4200
I did the nexus tutorial (Step 4, and 5), where they explained how to test, but somehow it doesn't work. So please help me.
https://nexusjs.org/docs/getting-started/tutorial

Answer 1

I have created a repo with parallel tests for the same here. The test environment setup is in the prisma folder and a similar helper is created in the tests folder.