createFixtures

Signature

function createFixtures<T extends PageObjectConstructorsMap>(
  pageObjects: T,
): Fixtures<FixturesFromMap<T>, {}, {}, {}>;

type PageObjectEntry<T> =
  | (new (page: Page) => T)
  | ((page: Page) => T);

type PageObjectConstructorsMap = Record<string, PageObjectEntry<unknown>>;

Usage

import { test as base } from "@playwright/test";
import { createFixtures } from "playwright-page-object";

export const test = base.extend<{
  checkoutPage: CheckoutPage;
  authPage: AuthPage;
}>(
  createFixtures({
    checkoutPage: CheckoutPage,
    authPage: (page) => new AuthPage(page, authConfig),
  }),
);

The <{ ... }> generic on base.extend tells TypeScript the fixture types. createFixtures produces matching runtime wiring.

Class vs factory detection

For each entry, createFixtures decides whether to new-call or directly call:

const isConstructor =
  typeof entry === "function" &&
  entry.prototype !== undefined &&
  entry.prototype.constructor === entry;

const instance = isConstructor
  ? new entry(page)
  : entry(page);

This means:

Entry shape	Detected as	Called as
`class Foo {}` (ES class)	constructor	`new entry(page)`
`function Foo() {}` (regular function)	constructor	`new entry(page)`
`(page) => new Foo(page, config)` (arrow)	factory	`entry(page)`

Use arrow functions for factories. Regular functions have a prototype and will be treated as constructors.

Type inference

FixturesFromMap<T> maps each entry to its instance type so that test.extend infers fixture types correctly:

createFixtures({
  homePage: HomePage,                     // homePage: HomePage
  authPage: (page) => new AuthPage(page), // authPage: AuthPage
});

You still pass the explicit generic to base.extend<{ homePage; authPage }> — Playwright’s extend requires it for stricter type narrowing.

When to use it

Your suite already uses Playwright fixtures.
You want a single point of configuration for page-object setup.
You need factories for page objects with custom constructor arguments.

Manual instantiation (new CheckoutPage(page) inside each test) is equally valid. The library does not require fixtures.