Integration Testing with GraphQL (Nexus, Apollo), Prisma, and PostgreSQL - postgresql

Question

I am trying to follow this tutorial to establish integration tests on our web application. Our stack currently includes Nexus, Next, Apollo, Prisma, and PostgreSQL.
I am using ApolloClient in place of GraphQLClient from graphql-request, I opted to use ApolloClient instead, especially since our web application is server less.
This is currently what I have inside the helper.ts, and the ApolloClient does work when I execute mutations. However, after executing a mutation on ApolloClient and checking if the data persists through Prisma, I get a null value.
Did I do these adjustments correctly? I am definitely missing something if Prisma is not querying correctly. Maybe there is a disconnect here between ApolloClient and Prisma or ApolloClient and the database? Any help would be much appreciated.
All of the code is below.
helper.ts
function graphqlTestContext() {
let serverInstance: ServerInfo | null = null;
return {
async before() {
const rootUrl = getRootUrl();
const httpLink = createHttpLink({
uri: rootUrl + "api/graphql",
credentials: "include",
fetch
});
const client = new ApolloClient({
// ssrMode: typeof window === "undefined",
link: httpLink,
cache: new InMemoryCache(),
});
return client;
},
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() {
// Generate a unique schema identifier for this test context
schema = `test_${nanoid()}`;
// Generate the pg connection string for the test schema
databaseUrl = `${process.env.ROOT_DB_URL}/testing?schema=${schema}`;
// Set the required environment variable to contain the connection string
// to our database test schema
process.env.DATABASE_URL = databaseUrl;
// Run the migrations to ensure our schema has the required structure
execSync(`${prismaBinary} migrate dev`, {
env: {
...process.env,
DATABASE_URL: databaseUrl,
},
});
// Construct a new Prisma Client connected to the generated Postgres schema
prismaClient = new PrismaClient();
return prismaClient;
},
async after() {
// Drop the schema after the tests have completed
const client = new Client({
connectionString: databaseUrl,
});
await client.connect();
await client.query(`DROP SCHEMA IF EXISTS "${schema}" CASCADE`);
await client.end();
// Release the Prisma Client connection
await prismaClient?.$disconnect();
},
}
User.int.test.ts
const ctx = createTestContext();
describe("User", () => {
it("creates a new user with REGISTER_MUTATION", async () => {
const userResult = await ctx.client.mutate({
mutation: gql`
mutation Register(
$firstName: String!
$lastName: String!
$email: String!
$password: String!
) {
registerUser(
firstName: $firstName
lastName: $lastName
email: $email
password: $password
) {
user {
email
firstName
}
}
}
`,
variables: {
firstName: "FirstName",
lastName: "LastName",
email: "test#email.com",
password: "password"
}
});
expect(userResult).toMatchInlineSnapshot(`
Object {
"data": Object {
"registerUser": Object {
"__typename": "UserLoginPayload",
"user": Object {
"__typename": "User",
"email": "test#email.com",
"firstName": "FirstName",
},
},
},
}
`);
});
it("verifies that user persists", async () => {
const persistedData = await ctx.prisma.user.findMany();
expect(persistedData).toMatchInlineSnapshot(`Array []`);
});
});

Answer 1

The reason is because graphql server is instantiated with different prisma client with its own db. And the prismaTestContext has its own prisma client with different db url.