Bug Description
In versions 8.0.3 and 8.1.0, if I set a MockAgent as global dispatcher, it no longer intercepts native Node.js fetch queries.
Reproducible By
test.js:
import { MockAgent, setGlobalDispatcher } from 'undici';
const agent = new MockAgent();
agent.disableNetConnect();
setGlobalDispatcher(agent);
agent.get('https://example.com')
.intercept({
method: 'GET',
path: '/v1/test',
})
.reply(() => {
return {
statusCode: 200,
data: { test: 123 },
}
});
const req = await fetch('https://example.com/v1/test')
console.log(req.status);
const data = await req.json();
console.log(data);Expected Behavior
It should intercept the query and return the mocked response.
Logs & Screenshots
➤ node test.js
404
<anonymous_script>:1
<!doctype html><html lang="en"><head><title>Example Domain</title><meta name="viewport" content="width=device-width, initial-scale=1"><style>body{background:#eee;width:60vw;margin:15vh auto;font-family:system-ui,sans-serif}h1{font-size:1.5em}div{opacity:0.8}a:link,a:visited{color:#348}</style></head><body><div><h1>Example Domain</h1><p>This domain is for use in documentation examples without needing permission. Avoid use in operations.</p><p><a href="https://iana.org/domains/example">Learn more</a></p></div></body></html>
^
SyntaxError: Unexpected token '<', "<!doctype "... is not valid JSON
at JSON.parse (<anonymous>)
Environment
Tested with Node.js 25.9.0 and 24.15.0.
Additional context
8.0.1 and 8.0.2 worked as expected. 8.0.0 also had this issue.
/cc @mcollina
Bug Description
In versions 8.0.3 and 8.1.0, if I set a MockAgent as global dispatcher, it no longer intercepts native Node.js
fetchqueries.Reproducible By
test.js:
Expected Behavior
It should intercept the query and return the mocked response.
Logs & Screenshots
Environment
Tested with Node.js 25.9.0 and 24.15.0.
Additional context
8.0.1 and 8.0.2 worked as expected. 8.0.0 also had this issue.
/cc @mcollina