can i have one database pool connection per worker ?
This thread is trying to answer question "Is it possible to maintain one database pool connection for all tests?"
Create connection in worker scope fixture perhaps? https://playwright.dev/docs/test-fixtures#worker-scoped-fixtures
export default class DB {
private pool: Pool;
private DBConfig = {
user: "db_user",
host: "localhost",
database: "dd",
password: "dd",
port: 5477, // Default PostgreSQL port is 5432
max: 10, // Maximum number of connections in the pool
idleTimeoutMillis: 30000, // Time a connection is kept idle before being closed
connectionTimeoutMillis: 2000, // Time to wait for a new connection if all are busy
allowExitOnIdle: false,
};
async getDBConnection(): Promise<Pool> {
if (!this.pool) {
this.pool = new Pool(this.DBConfig);
console.log("\x1b[32m" + `---------> √ DB connection has been established! <---------`);
return this.pool;
} else {
console.log("\x1b[32m" + `---------> √ DB connection is already established! <---------`);
return this.pool;
}
}
}
First thing what is the problem attempting to be solved. Connection pooling is more a function for the database and client libraries to access the db. Depending on the database can be the DB routines may start services and connection pooling is more for performance. As for SQL if the connection string differs you won't share a connection. Remember writing a tool when i was in support to show/test user connection pooling to SQL and it was working. Never saw where you don't want it. And if it is on, depending on the DB it will be within the DB routines managed by the DB client routines...
The problem is that i cant build a singletone function through which i will establish the db connection once before all tests start then use the existing connection to execute the required query.
The singletone function seems will keep establish the connection for each test no matter if you add it in global setup or not
Also why can't the singleton check if dbConnection == null. We all know what happens when assumptions are made. I'm more C# and would think a lock to wrap the db init code. Check if the dbConnectin == null, create a lock and init the db connection. Should never get more than one conection then?
I'm having this same issue. I'm finding that each test is isolated and I cannot create a single mock DB instance that works across all tests. If I use fixtures, it recreates the mock DB on every test. If I use globalSetup or dependencies, the mock database doesn't live long enough to be used by any test. I tried running it as a webServer but so far no luck. @amrsa what did you end up doing?
I think the execution model makes having anything be truly ‘global’ unlikely because each worker is independent.
The best I can come up with is having a connection pool as a worker fixture and the client as a test fixture. Or having a service external to the tests. In my case I have a service that runs in the background and exposes an api that the tests interact with not sure how that would integrate with db connections though.
Connection pooling depending on what we are talking about, working on say MSSQL and MDAC SQL's connection pooling is down below where you'll be able to access and pass around, even worse you have a bunch of security issues sharing and passing them around if you desire. Connection pooling, while i can only speak specifically to SQL's connection pooling, it is located deeper down in the DB provider then you'll be able to utilize from what i know.
Related Ask AI answer for "How do I set up a single database pool connection for all tests in Playwright Test using the globalSetup or beforeAll hook?".
Answer
Sure, you can set up a single database pool connection for all your tests using the globalSetup or beforeAll hook in @playwright/test.
First, create a global.setup.ts file at your project's root level. This file should export a function that initializes your database pool connection and stores it in a global variable. Here's an example:
// global.setup.ts
import { Pool } from 'your-database-library';
let dbPool: Pool;
export default async function globalSetup(config: any) {
dbPool = new Pool(config.databaseOptions);
}Next, specify the globalSetup option in your Playwright config file (playwright.config.ts) and provide the path to your global.setup.ts file:
// playwright.config.ts
import { defineConfig } from '@playwright/test';
export default defineConfig({
globalSetup: './global.setup.ts',
});This way, the globalSetup function will run once before all tests, establishing a single database pool connection. Each test can then access this shared dbPool variable for their database operations.
Remember, if you're using multiple workers with parallel execution, each worker will have its own instance of the global setup. If you want a single database pool connection per worker, initialize the connection in the beforeAll hook instead.
This efficient sharing of resources ensures consistent behavior across your test suite. For more tips on efficient testing with Playwright, check out this blog post.
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