Add anvil saver example

#334

docs/api.md

@@ -729,6 +729,7 @@ Create and return an instance of the class bot.
  * keepAlive : send keep alive packets : default to true
  * checkTimeoutInterval : default to `30*1000` (30s), check if keepalive received at that period, disconnect otherwise.
  * loadInternalPlugins : defaults to true
+ * storageBuilder : an optional function, takes as argument version and worldName and return an instance of something with the same API as prismarine-provider-anvil. Will be used to save the world.
  * plugins : object : defaults to {}
    - pluginName : false : don't load internal plugin with given name ie. `pluginName`
    - pluginName : true : load internal plugin with given name ie. `pluginName` even though loadInternalplugins is set to false

examples/anvil_saver/package.json

@@ -0,0 +1,9 @@
+{
+  "name": "mineflayer-example",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+    "prismarine-provider-anvil": "^2.3.0"
+  },
+  "description": "A mineflayer example"
+}

examples/anvil_saver/saver.js

@@ -0,0 +1,30 @@
+/*
+ * This example demonstrates how to save a world with mineflayer and
+ * https://github.com/PrismarineJS/prismarine-provider-anvil
+ */
+
+const mineflayer = require('mineflayer')
+const fs = require('fs')
+
+if (process.argv.length < 4 || process.argv.length > 6) {
+  console.log('Usage : node saver.js <host> <port> [<name>] [<password>]')
+  process.exit(1)
+}
+
+const bot = mineflayer.createBot({
+  host: process.argv[2],
+  port: parseInt(process.argv[3]),
+  username: process.argv[4] ? process.argv[4] : 'saver',
+  password: process.argv[5],
+  storageBuilder: ({ version, worldName }) => {
+    const Anvil = require('prismarine-provider-anvil').Anvil(version)
+    fs.mkdirSync(worldName)
+    return new Anvil(worldName)
+  }
+})
+
+bot.on('spawn', () => {
+  bot.waitForChunksToLoad(() => {
+    console.log('World saved!')
+  })
+})

lib/plugins/blocks.js

@@ -14,13 +14,13 @@ const paintingFaceToVec = [
   new Vec3(1, 0, 0)
 ]
 
-function inject (bot, { version }) {
+function inject (bot, { version, storageBuilder }) {
   const nbt = require('prismarine-nbt')
   const Block = require('prismarine-block')(version)
   const Chunk = require('prismarine-chunk')(version)
   const ChatMessage = require('prismarine-chat')(version)
   const World = require('prismarine-world')(version)
-  bot.world = new World().sync
+  bot.world = new World(null, storageBuilder({ version: bot.version, worldName: 'overworld' })).sync
   const signs = {}
   const paintingsByPos = {}
   const paintingsById = {}
@@ -452,7 +452,7 @@ function inject (bot, { version }) {
   bot._client.on('respawn', (packet) => {
     if (dimension === packet.dimension) return
     dimension = packet.dimension
-    bot.world = new World().sync
+    bot.world = new World(null, storageBuilder({ version: bot.version, worldName: 'overworld' })).sync
   })
 
   bot.findBlock = findBlock