refactor: unify close/destroy

lib/agent.js

@@ -1,20 +1,14 @@
 'use strict'
 
-const {
-  ClientClosedError,
-  InvalidArgumentError,
-  ClientDestroyedError
-} = require('./core/errors')
-const { kClients, kRunning } = require('./core/symbols')
-const Dispatcher = require('./dispatcher')
+const { InvalidArgumentError } = require('./core/errors')
+const { kClients, kRunning, kClose, kDestroy, kDispatch } = require('./core/symbols')
+const DispatcherBase = require('./dispatcher-base')
 const Pool = require('./pool')
 const Client = require('./client')
 const util = require('./core/util')
 const RedirectHandler = require('./handler/redirect')
 const { WeakRef, FinalizationRegistry } = require('./compat/dispatcher-weakref')()
 
-const kDestroyed = Symbol('destroyed')
-const kClosed = Symbol('closed')
 const kOnConnect = Symbol('onConnect')
 const kOnDisconnect = Symbol('onDisconnect')
 const kOnConnectionError = Symbol('onConnectionError')
@@ -30,7 +24,7 @@ function defaultFactory (origin, opts) {
     : new Pool(origin, opts)
 }
 
-class Agent extends Dispatcher {
+class Agent extends DispatcherBase {
   constructor ({ factory = defaultFactory, maxRedirections = 0, connect, ...options } = {}) {
     super()
 
@@ -60,8 +54,6 @@ class Agent extends Dispatcher {
         this[kClients].delete(key)
       }
     })
-    this[kClosed] = false
-    this[kDestroyed] = false
 
     const agent = this
 
@@ -94,76 +86,38 @@ class Agent extends Dispatcher {
     return ret
   }
 
-  dispatch (opts, handler) {
-    if (!handler || typeof handler !== 'object') {
-      throw new InvalidArgumentError('handler must be an object.')
+  [kDispatch] (opts, handler) {
+    let key
+    if (opts.origin && (typeof opts.origin === 'string' || opts.origin instanceof URL)) {
+      key = String(opts.origin)
+    } else {
+      throw new InvalidArgumentError('opts.origin must be a non-empty string or URL.')
     }
 
-    try {
-      if (!opts || typeof opts !== 'object') {
-        throw new InvalidArgumentError('opts must be an object.')
-      }
-
-      let key
-      if (opts.origin && (typeof opts.origin === 'string' || opts.origin instanceof URL)) {
-        key = String(opts.origin)
-      } else {
-        throw new InvalidArgumentError('opts.origin must be a non-empty string or URL.')
-      }
-
-      if (this[kDestroyed]) {
-        throw new ClientDestroyedError()
-      }
-
-      if (this[kClosed]) {
-        throw new ClientClosedError()
-      }
+    const ref = this[kClients].get(key)
 
-      const ref = this[kClients].get(key)
-
-      let dispatcher = ref ? ref.deref() : null
-      if (!dispatcher) {
-        dispatcher = this[kFactory](opts.origin, this[kOptions])
-          .on('drain', this[kOnDrain])
-          .on('connect', this[kOnConnect])
-          .on('disconnect', this[kOnDisconnect])
-          .on('connectionError', this[kOnConnectionError])
-
-        this[kClients].set(key, new WeakRef(dispatcher))
-        this[kFinalizer].register(dispatcher, key)
-      }
-
-      const { maxRedirections = this[kMaxRedirections] } = opts
-      if (maxRedirections != null && maxRedirections !== 0) {
-        opts = { ...opts, maxRedirections: 0 } // Stop sub dispatcher from also redirecting.
-        handler = new RedirectHandler(this, maxRedirections, opts, handler)
-      }
-
-      return dispatcher.dispatch(opts, handler)
-    } catch (err) {
-      if (typeof handler.onError !== 'function') {
-        throw new InvalidArgumentError('invalid onError method')
-      }
+    let dispatcher = ref ? ref.deref() : null
+    if (!dispatcher) {
+      dispatcher = this[kFactory](opts.origin, this[kOptions])
+        .on('drain', this[kOnDrain])
+        .on('connect', this[kOnConnect])
+        .on('disconnect', this[kOnDisconnect])
+        .on('connectionError', this[kOnConnectionError])
 
-      handler.onError(err)
+      this[kClients].set(key, new WeakRef(dispatcher))
+      this[kFinalizer].register(dispatcher, key)
     }
-  }
-
-  get closed () {
-    return this[kClosed]
-  }
-
-  get destroyed () {
-    return this[kDestroyed]
-  }
 
-  close (callback) {
-    if (callback != null && typeof callback !== 'function') {
-      throw new InvalidArgumentError('callback must be a function')
+    const { maxRedirections = this[kMaxRedirections] } = opts
+    if (maxRedirections != null && maxRedirections !== 0) {
+      opts = { ...opts, maxRedirections: 0 } // Stop sub dispatcher from also redirecting.
+      handler = new RedirectHandler(this, maxRedirections, opts, handler)
     }
 
-    this[kClosed] = true
+    return dispatcher.dispatch(opts, handler)
+  }
 
+  async [kClose] () {
     const closePromises = []
     for (const ref of this[kClients].values()) {
       const client = ref.deref()
@@ -173,27 +127,10 @@ class Agent extends Dispatcher {
       }
     }
 
-    if (!callback) {
-      return Promise.all(closePromises)
-    }
-
-    // Should never error.
-    Promise.all(closePromises).then(() => process.nextTick(callback))
+    await Promise.all(closePromises)
   }
 
-  destroy (err, callback) {
-    if (typeof err === 'function') {
-      callback = err
-      err = null
-    }
-
-    if (callback != null && typeof callback !== 'function') {
-      throw new InvalidArgumentError('callback must be a function')
-    }
-
-    this[kClosed] = true
-    this[kDestroyed] = true
-
+  async [kDestroy] (err) {
     const destroyPromises = []
     for (const ref of this[kClients].values()) {
       const client = ref.deref()
@@ -203,12 +140,7 @@ class Agent extends Dispatcher {
       }
     }
 
-    if (!callback) {
-      return Promise.all(destroyPromises)
-    }
-
-    // Should never error.
-    Promise.all(destroyPromises).then(() => process.nextTick(callback))
+    await Promise.all(destroyPromises)
   }
 }