[Backport 7.x] The agent function should take the Connection contructor options as argument (#1334)

Co-authored-by: Tomas Della Vedova <delvedor@users.noreply.github.com>

docs/configuration.asciidoc

@@ -149,7 +149,9 @@ const client = new Client({
 
 const client = new Client({
   node: 'http://localhost:9200',
-  agent: () => new CustomAgent()
+  // the function takes as parameter the option
+  // object passed to the Connection constructor
+  agent: (opts) => new CustomAgent()
 })
 
 const client = new Client({

lib/Connection.d.ts

@@ -28,9 +28,9 @@ import * as https from 'https'
 import * as hpagent from 'hpagent'
 import { ConnectionOptions as TlsConnectionOptions } from 'tls'
 
-export declare type agentFn = () => any;
+export declare type agentFn = (opts: ConnectionOptions) => any;
 
-interface ConnectionOptions {
+export interface ConnectionOptions {
   url: URL;
   ssl?: TlsConnectionOptions;
   id?: string;

lib/Connection.js

@@ -53,7 +53,7 @@ class Connection {
     }
 
     if (typeof opts.agent === 'function') {
-      this.agent = opts.agent()
+      this.agent = opts.agent(opts)
     } else if (opts.agent === false) {
       this.agent = undefined
     } else {

test/types/connection.test-d.ts

@@ -20,22 +20,35 @@
 import { expectType } from 'tsd'
 import { URL } from 'url'
 import { Connection } from '../../'
+import { ConnectionOptions } from '../../lib/Connection'
 
-const conn = new Connection({
-  url: new URL('http://localhost:9200'),
-  ssl: { ca: 'string' },
-  id: 'id',
-  headers: {},
-  agent: { keepAlive: false },
-  status: 'alive',
-  roles: { master: true },
-  auth: { username: 'username', password: 'password' }
-})
+{
+  const conn = new Connection({
+    url: new URL('http://localhost:9200'),
+    ssl: { ca: 'string' },
+    id: 'id',
+    headers: {},
+    agent: { keepAlive: false },
+    status: 'alive',
+    roles: { master: true },
+    auth: { username: 'username', password: 'password' }
+  })
 
-expectType<Connection>(conn)
-expectType<URL>(conn.url)
-expectType<string>(conn.id)
-expectType<Record<string, any>>(conn.headers)
-expectType<number>(conn.deadCount)
-expectType<number>(conn.resurrectTimeout)
-expectType<string>(conn.status)
+  expectType<Connection>(conn)
+  expectType<URL>(conn.url)
+  expectType<string>(conn.id)
+  expectType<Record<string, any>>(conn.headers)
+  expectType<number>(conn.deadCount)
+  expectType<number>(conn.resurrectTimeout)
+  expectType<string>(conn.status)
+}
+
+{
+  const conn = new Connection({
+    url: new URL('http://localhost:9200'),
+    agent (opts) {
+      expectType<ConnectionOptions>(opts)
+      return 'the agent'
+    }
+  })
+}

test/unit/connection.test.js

@@ -152,7 +152,7 @@ test('Basic (https with ssl agent)', t => {
 })
 
 test('Custom http agent', t => {
-  t.plan(5)
+  t.plan(6)
 
   function handler (req, res) {
     t.match(req.headers, {
@@ -172,7 +172,12 @@ test('Custom http agent', t => {
     agent.custom = true
     const connection = new Connection({
       url: new URL(`http://localhost:${port}`),
-      agent: () => agent
+      agent: opts => {
+        t.match(opts, {
+          url: new URL(`http://localhost:${port}`)
+        })
+        return agent
+      }
     })
     t.true(connection.agent.custom)
     connection.request({