fix: preserve connect option in H2CClient (#5000)

Signed-off-by: Kamat, Trivikram <16024985+trivikr@users.noreply.github.com>

Author: trivikr

lib/dispatcher/h2c-client.js

@@ -15,7 +15,7 @@ class H2CClient extends Client {
       )
     }
 
-    const { connect, maxConcurrentStreams, pipelining, ...opts } =
+    const { maxConcurrentStreams, pipelining, ...opts } =
             clientOpts ?? {}
     let defaultMaxConcurrentStreams = 100
     let defaultPipelining = 100

test/h2c-client.js

@@ -140,6 +140,32 @@ test('Connect to h2c server over a unix domain socket', { skip: process.platform
   })
 })
 
+test('Should pass custom connect function to Client', async t => {
+  const planner = tspl(t, { plan: 3 })
+
+  const connectError = new Error('custom connect error')
+  const socketPath = '/var/run/test.sock'
+  const client = new H2CClient('http://localhost', {
+    socketPath,
+    connect (opts, cb) {
+      planner.strictEqual(opts.socketPath, socketPath)
+      planner.strictEqual(opts.allowH2, true)
+      cb(connectError, null)
+    }
+  })
+
+  t.after(() => client.close())
+
+  client.request({
+    path: '/',
+    method: 'GET'
+  }, (err) => {
+    planner.strictEqual(err, connectError)
+  })
+
+  await planner.completed
+})
+
 test('Should throw if bad useH2c has been passed', async t => {
   t = tspl(t, { plan: 1 })