Intergrate with `msw` mock service

[himself65]

Description

I think it's possible to generate mock server handler for better unit testing

[mrlubos]

@himself65 What do you do currently?

[mrlubos]

Related to #1486

[mrlubos]

Closing this in favour of #1486, please move any discussion there!

[mrlubos]

Hey @himself65, are you using MSW Source? What's the benefit for you to have Hey API generate MSW handlers?

[himself65]

So I don't need manually write random data code

[mrlubos]

@himself65 which parts do you still need to write manually when using MSW Source?

[mkeyy0]

Also, I recently found msw-auto-mock, looks like it also covers all the functionality you might need. (When you prefer static generation over runtime)

[mrlubos]

@mkeyy0 did you end up using it? The GenAI feature looks interesting

[mkeyy0]

No, I've just found it and right now trying it in my repo, I'll give you feedback a bit later during the day

[mkeyy0]

After a small investigation, it looks like msw-auto-mock doesn't work for me by the following reasons:

• It looks like it is developed to be used in the browser environment . It uses the next function that increases the counter using closure after each request execution and then makes a % on a possible request length which makes the request order of subsequent requests unpredictable. So this approach doesn't work for tests
• Doesn't have built-in typescript support

Also, some things to say about MSW Source. I quite don't like the approach with runtime-generated data based on the schema, it looks like it also was developed for the browser environment rather than for the test one. Also right now it is not possible to get a specific response for a specific endpoint in a test environment. You can do it by adding ?response={response_code} query parameter but this doesn't work for tests of course.

I'm not even sure if should we ask for a plugin from your side or if should it be some additional functionality provided by MSW Source package. But from my side what I'd like to have from the plugin:

• Support file generation based on the API schema of handlers. (200 status is always a default one that is sent)
• Support generation of the factory-like function to create responses described in the OpenAPI schema. For example UserCreateUnauthorizedResponse etc. Why should it be a factory? Because one response object can't be read twice. You can see this issue for more info Generated HAR handlers cannot respond to the same URL more than once mswjs/source#66
• TypeScript support.

File as output is the main feature I guess, because it simplifies debugging and you can change it, while in runtime you can't do anything.

@mrlubos

[mrlubos]

@mkeyy0 just want to say I appreciate these comments! Noted and will be taken into consideration. There's a draft pull request with the MSW plugin btw if you haven't seen, slowly working on it