Msw/2/Callback Signature

Following the original msw upgrade guide, the signature of the request handler have changed. This codemod hard replaces the callback signature to the new one and cleans up unused variables.

NOTE: This codemod should be applied after running all the other codemods present in the upgrade-recipe that are related to req, res, ctx objects. On its own, this codemod makes no sense to be run, and will most likely not do what you want.

WARNING

This codemod runs .fixUnusedIdentifiers() on a source file you are running it on. This would remove any unused declarations in the file. This is due to atomicity of this mod, which blindly inserts the callback structure into each msw handler callback and then cleans up the variables that are not used.

Before

import { http } from 'msw';

http.get('/resource', (req, res, ctx) => {
	return HttpResponse.json({ id: 'abc-123' });
});

After

import { http } from 'msw';

http.get('/resource', () => {
	return HttpResponse.json({ id: 'abc-123' });
});

Before

import { http } from 'msw';

http.get('/resource', (req, res, ctx) => {
	const userCookie = cookies.user;
	const url = new URL(request.url);

	doSomething(url);
	userCookie.doSomething();

	return HttpResponse.json({ id: 'abc-123' });
});

After

import { http } from 'msw';

http.get('/resource', ({ request, cookies }) => {
	const userCookie = cookies.user;
	const url = new URL(request.url);

	doSomething(url);
	userCookie.doSomething();

	return HttpResponse.json({ id: 'abc-123' });
});