chore: use maxSockets:1 for some flaky arborist reify tests

workspaces/arborist/test/arborist/reify.js

@@ -127,6 +127,7 @@ const {
   stop,
   registry,
   advisoryBulkResponse,
+  oneSocket,
 } = require('../fixtures/server.js')
 
 t.before(start)
@@ -170,7 +171,7 @@ t.test('update a yarn.lock file', async t => {
 })
 
 t.test('weirdly broken lockfile without resolved value', t =>
-  t.resolveMatchSnapshot(printReified(fixture(t, 'dep-missing-resolved'))))
+  t.resolveMatchSnapshot(printReified(fixture(t, 'dep-missing-resolved'), oneSocket(t))))
 
 t.test('testing-peer-deps package', t =>
   t.resolveMatchSnapshot(printReified(fixture(t, 'testing-peer-deps'))))
@@ -1417,7 +1418,7 @@ t.test('do not reify root when root matches duplicated metadep', async t => {
 
 t.test('reify properly with all deps when lockfile is ancient', async t => {
   const path = fixture(t, 'sax')
-  const tree = await reify(path)
+  const tree = await reify(path, oneSocket(t))
   t.matchSnapshot(printTree(tree))
   fs.statSync(path + '/node_modules/tap/node_modules/.bin/nyc')
 })

workspaces/arborist/test/fixtures/server.js

@@ -241,6 +241,18 @@ exports.registry = `http://localhost:${PORT}/`
 exports.start = startServer
 exports.stop = () => exports.server.close()
 
+exports.oneSocket = (t) => {
+  t.comment('using http.Agent with maxSockets:1, this is a hack that should be fixed')
+  // work around an unknown issue for know where agents on localhost need a
+  // low maxSockets to avoid ECONNRESET issues when dealing with ipv4 and ipv6
+  // dns resolution (i think)
+  return {
+    agent: new http.Agent({
+      maxSockets: 1,
+    }),
+  }
+}
+
 if (require.main === module) {
   startServer()
     .then(() => console.log(`Mock registry live at:\n${exports.registry}\nPress ^D to close gracefully.`))