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integration with miragejs

wickynilliamsposted in #help-playwright
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hey all. i have a SPA which uses a mock "server" provided by https://miragejs.com/, and i have some tests written with playwright. this works great so far! but now i want to be able to seed mirage with specific data per test, so that i can test more scenarios.

note: mirage is not a server as such, it is in-memory in the browser (not a service worker). it intercepts fetch calls and returns data you have seeded it with.

i created a custom fixture which allows me to do things like: await seed.create("pet", { name: "fido" }), which proxies to page.evaluate , ultimately calling a method on a mirage instance. btw fixtures are really neat!

however i have a bit of a chicken and egg problem. since mirage is in-memory in the browser, i cannot set data before i goto() a page, but i need the data to be there before loading the page, so that any fetches return the specific data for my test.

my workaround so far has been to first goto('/'), then seed data, then only navigate via links (since it's an SPA, no reload), avoiding further use of goto (since it would clear the in-memory mirage instace). but i don't think this is sustainable/scalable, and will be confusing to other devs. so i am looking for other approaches.

i would appreciate any suggestions. one idea i am toying with is for my custom seed fixture to write to storageState, allowing me to rehydrate migrage on page load. but i am wondering if there is a more natural hook for this kind of node/browser/page interplay?

This thread is trying to answer question "How can one seed Mirage with specific data per test before loading the page in a SPA, and how can one setup Mirage for end-to-end tests and access it from within the tests?"

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I'm also trying to setup mirage for e2e tests. How did you setup the mirage instance in your app and how are you able to access it from within the tests? 🙂 I've been struggling with things like context.addInitScript. Would you be able to share some minimal code snippets for this integration part?


oh hey, only just saw this!


i'll do a little explanation shortly

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