msw not intercepting network requests in Node.js 18
When I upgraded Node.js from 16 to 18, msw stopped intercepting network requests in my tests.
Cause
Node.js 18 added a built-in fetch API. This built-in fetch is implemented using undici, not Node's http module.
msw intercepts network requests by overriding the http module. So it cannot intercept requests made through undici.
Solution
Replace the global fetch with node-fetch in your test setup file.
import fetch from 'node-fetch';
global.fetch = fetch as typeof global.fetch;With this change, fetch calls in your code will use node-fetch, which goes through the http module. msw can then intercept those requests as expected.