chore: refactor main code into smaller parts

lib/pubsub.js

@@ -0,0 +1,80 @@
+'use strict'
+
+const debug = require('./debug')
+const SUBSCRIBE_COMMANDS = {
+  subscribe: true,
+  unsubscribe: true,
+  psubscribe: true,
+  punsubscribe: true
+}
+
+function subscribeUnsubscribe (client, reply, type) {
+  // Subscribe commands take an optional callback and also emit an event, but only the Last_ response is included in the callback
+  // The pub sub commands return each argument in a separate return value and have to be handled that way
+  const commandObj = client.commandQueue.get(0)
+  const buffer = client.options.returnBuffers || client.options.detectBuffers && commandObj.bufferArgs
+  const channel = (buffer || reply[1] === null) ? reply[1] : reply[1].toString()
+  const count = +reply[2] // Return the channel counter as number no matter if `stringNumbers` is activated or not
+  debug(type, channel)
+
+  // Emit first, then return the callback
+  if (channel !== null) { // Do not emit or "unsubscribe" something if there was no channel to unsubscribe from
+    if (type === 'subscribe' || type === 'psubscribe') {
+      client.subscriptionSet[`${type}_${channel}`] = channel
+    } else {
+      const innerType = type === 'unsubscribe' ? 'subscribe' : 'psubscribe' // Make types consistent
+      delete client.subscriptionSet[`${innerType}_${channel}`]
+    }
+    client.emit(type, channel, count)
+    client.subscribeChannels.push(channel)
+  }
+
+  if (commandObj.argsLength === 1 || client.subCommandsLeft === 1 || commandObj.argsLength === 0 && (count === 0 || channel === null)) {
+    if (count === 0) { // Unsubscribed from all channels
+      var runningCommand
+      var i = 1
+      client.pubSubMode = 0 // Deactivating pub sub mode
+      // This should be a rare case and therefore handling it this way should be good performance wise for the general case
+      for (runningCommand = client.commandQueue.get(i); runningCommand !== undefined; runningCommand = client.commandQueue.get(i)) {
+        if (SUBSCRIBE_COMMANDS[runningCommand.command]) {
+          client.pubSubMode = i // Entering pub sub mode again
+          break
+        }
+        i++
+      }
+    }
+    client.commandQueue.shift()
+    commandObj.callback(null, [count, client.subscribeChannels])
+    client.subscribeChannels = []
+    client.subCommandsLeft = 0
+  } else {
+    if (client.subCommandsLeft !== 0) {
+      client.subCommandsLeft--
+    } else {
+      client.subCommandsLeft = commandObj.argsLength ? commandObj.argsLength - 1 : count
+    }
+  }
+}
+
+function returnPubSub (client, reply) {
+  const type = reply[0].toString()
+  if (type === 'message') { // Channel, message
+    if (!client.options.returnBuffers || client.messageBuffers) { // Backwards compatible. Refactor this in v.3 to always return a string on the normal emitter
+      client.emit('message', reply[1].toString(), reply[2].toString())
+      client.emit('messageBuffer', reply[1], reply[2])
+    } else {
+      client.emit('message', reply[1], reply[2])
+    }
+  } else if (type === 'pmessage') { // Pattern, channel, message
+    if (!client.options.returnBuffers || client.messageBuffers) { // Backwards compatible. Refactor this in v.3 to always return a string on the normal emitter
+      client.emit('pmessage', reply[1].toString(), reply[2].toString(), reply[3].toString())
+      client.emit('pmessageBuffer', reply[1], reply[2], reply[3])
+    } else {
+      client.emit('pmessage', reply[1], reply[2], reply[3])
+    }
+  } else {
+    subscribeUnsubscribe(client, reply, type)
+  }
+}
+
+module.exports = returnPubSub