Introduce switch and void, remove condition

package.json

@@ -47,7 +47,7 @@
     "readable-stream": "^1.1.0",
     "superagent": "~0.10.0",
     "ursa-purejs": "0.0.3",
-    "minecraft-data": "0.6.0"
+    "minecraft-data": "0.7.0"
   },
   "optionalDependencies": {
     "ursa": "~0.8.0"

src/browser.js

@@ -16,5 +16,4 @@ module.exports = {
   packetStates: packetIndexes.packetStates,
   types: serializer.types,
   get: serializer.get,
-  evalCondition: utils.evalCondition,
 };

src/datatypes/conditional.js

@@ -1,25 +1,41 @@
-var evalCondition = require("../utils").evalCondition;
+var { getField, getFieldInfo } = require('../utils');
 
 module.exports = {
-  'condition': [readCondition, writeCondition, sizeOfCondition]
+  'switch': [readSwitch, writeSwitch, sizeOfSwitch],
 };
 
-function readCondition(buffer, offset, typeArgs, rootNode) {
-  if(!evalCondition(typeArgs, rootNode))
-    return {value: null, size: 0};
-  return this.read(buffer, offset, typeArgs.type, rootNode);
+function readSwitch(buffer, offset, typeArgs, rootNode) {
+  var compareTo = getField(typeArgs.compareTo, rootNode);
+  var fieldInfo;
+  if (typeof typeArgs.fields[compareTo] === 'undefined' && typeof typeArgs.default === "undefined")
+    throw new Error(compareTo + " has no associated fieldInfo in switch");
+  else if (typeof typeArgs.fields[compareTo] === 'undefined')
+    fieldInfo = getFieldInfo(typeArgs.default);
+  else
+    fieldInfo = getFieldInfo(typeArgs.fields[compareTo]);
+  return this.read(buffer, offset, fieldInfo, rootNode);
 }
 
-function writeCondition(value, buffer, offset, typeArgs, rootNode) {
-  if(!evalCondition(typeArgs, rootNode))
-    return offset;
-
-  return this.write(value, buffer, offset, typeArgs.type, rootNode);
+function writeSwitch(value, buffer, offset, typeArgs, rootNode) {
+  var compareTo = getField(typeArgs.compareTo, rootNode);
+  var fieldInfo;
+  if (typeof typeArgs.fields[compareTo] === 'undefined' && typeof typeArgs.default === "undefined")
+    throw new Error(compareTo + " has no associated fieldInfo in switch");
+  else if (typeof typeArgs.fields[compareTo] === 'undefined')
+    fieldInfo = getFieldInfo(typeArgs.default);
+  else
+    fieldInfo = getFieldInfo(typeArgs.fields[compareTo]);
+  return this.write(value, buffer, offset, fieldInfo, rootNode);
 }
 
-function sizeOfCondition(value, typeArgs, rootNode) {
-  if(!evalCondition(typeArgs, rootNode))
-    return 0;
-
-  return this.sizeOf(value, typeArgs.type, rootNode);
+function sizeOfSwitch(value, typeArgs, rootNode) {
+  var compareTo = getField(typeArgs.compareTo, rootNode);
+  var fieldInfo;
+  if (typeof typeArgs.fields[compareTo] === 'undefined' && typeof typeArgs.default === "undefined")
+    throw new Error(compareTo + " has no associated fieldInfo in switch");
+  else if (typeof typeArgs.fields[compareTo] === 'undefined')
+    fieldInfo = getFieldInfo(typeArgs.default);
+  else
+    fieldInfo = getFieldInfo(typeArgs.fields[compareTo]);
+  return this.sizeOf(value, fieldInfo, rootNode);
 }

src/datatypes/structures.js

@@ -1,6 +1,5 @@
 var getField = require("../utils").getField;
 var debug = require("../debug");
-var evalCondition = require("../utils").evalCondition;
 
 module.exports = {
   'array': [readArray, writeArray, sizeOfArray],

src/datatypes/utils.js

@@ -6,7 +6,8 @@ module.exports = {
   'varint': [readVarInt, writeVarInt, sizeOfVarInt],
   'bool': [readBool, writeBool, 1],
   'string': [readString, writeString, sizeOfString],
-  'buffer': [readBuffer, writeBuffer, sizeOfBuffer]
+  'buffer': [readBuffer, writeBuffer, sizeOfBuffer],
+  'void': [readVoid, writeVoid, 0],
 };
 
 function readVarInt(buffer, offset) {
@@ -131,3 +132,14 @@ function sizeOfBuffer(value, typeArgs, rootNode) {
   }
   return size + value.length;
 }
+
+function readVoid() {
+  return {
+    value: undefined,
+    size: 0,
+  };
+}
+
+function writeVoid(value, buffer, offset) {
+  return offset;
+}

src/index.js

@@ -24,7 +24,6 @@ module.exports = {
   packetStates: packetIndexes.packetStates,
   types: serializer.types,
   get: serializer.get,
-  evalCondition: utils.evalCondition,
   ping: require('./ping'),
   yggdrasil: Yggdrasil,
   version: version.version,

src/transforms/serializer.js

@@ -47,7 +47,6 @@ proto.addTypes(conditional);
 
 module.exports.types = proto.types;
 
-var evalCondition = require("../utils").evalCondition;
 var version = require('../version');
 var packets = require('minecraft-data')(version.majorVersion).protocol;
 var readPackets = require("../packets").readPackets;
@@ -88,8 +87,8 @@ function createPacketBuffer(packetId, state, params, isServer) {
   offset = utils.varint[1](packetId, buffer, offset);
   packet.forEach(function(fieldInfo) {
     var value = params[fieldInfo.name];
-    // TODO : A better check is probably needed
-    if(typeof value === "undefined" && fieldInfo.type != "count" && (fieldInfo.type != "condition" || evalCondition(fieldInfo.typeArgs, params)))
+    // TODO : This check belongs to the respective datatype.
+    if(typeof value === "undefined" && fieldInfo.type != "count")
       debug(new Error("Missing Property " + fieldInfo.name).stack);
     offset = proto.write(value, buffer, offset, fieldInfo.type, params);
   });

src/utils.js

@@ -1,7 +1,6 @@
 module.exports = {
   getField: getField,
   getFieldInfo: getFieldInfo,
-  evalCondition: evalCondition
 };
 
 function getField(countField, rootNode) {
@@ -23,14 +22,3 @@ function getFieldInfo(fieldInfo) {
   else
     throw new Error("Not a fieldinfo");
 }
-
-function evalCondition(condition, field_values) {
-  var field_value_to_test = "this" in condition && condition["this"] ? field_values["this"][condition.field] : field_values[condition.field];
-  var b = condition.values.some(function(value) {
-    return field_value_to_test === value;
-  });
-  if("different" in condition && condition["different"])
-    return !b;
-  else
-    return b;
-}

test/test.js

@@ -15,7 +15,7 @@ var mc = require('../')
   , SURVIVE_TIME = 10000
   , MC_SERVER_PATH = path.join(__dirname, 'server')
   , getFieldInfo = require('../dist/utils').getFieldInfo
-  , evalCondition = require('../dist/utils').evalCondition
+  , getField = require('../dist/utils').getField
   ;
 
 var defaultServerProps = {
@@ -62,30 +62,16 @@ var values = {
   'ubyte': 8,
   'string': "hi hi this is my client string",
   'buffer': new Buffer(8),
-  'array': function(_typeArgs, packet) {
-    var typeArgs = getFieldInfo(_typeArgs.type)
-    if(typeof values[typeArgs.type] === "undefined") {
-      throw new Error("No data type for " + typeArgs.type);
-    }
-    if(typeof values[typeArgs.type] === "function") {
-      return [values[typeArgs.type](typeArgs.typeArgs, packet)];
-    }
-    return [values[typeArgs.type]];
+  'array': function(typeArgs, packet) {
+    return [getValue(typeArgs.type, packet)];
   },
   'container': function(typeArgs, packet) {
     var results = {};
     for(var index in typeArgs) {
-      if(typeof values[getFieldInfo(typeArgs[index].type).type] === "undefined") {
-        throw new Error("No data type for " + typeArgs[index].type);
-      }
-      if(typeof values[getFieldInfo(typeArgs[index].type).type] === "function") {
       var backupThis = packet.this;
       packet.this = results;
-        results[typeArgs[index].name] = values[getFieldInfo(typeArgs[index].type).type](getFieldInfo(typeArgs[index].type).typeArgs, packet);
+      results[typeArgs[index].name] = getValue(typeArgs[index].type, packet);
       packet.this = backupThis;
-      } else {
-        results[typeArgs[index].name] = values[getFieldInfo(typeArgs[index].type).type];
-      }
     }
     return results;
   },
@@ -127,16 +113,25 @@ var values = {
   'UUID': "00112233-4455-6677-8899-aabbccddeeff",
   'position': {x: 12, y: 332, z: 4382821},
   'restBuffer': new Buffer(0),
-  'condition': function(typeArgs, packet) {
-    if (evalCondition(typeArgs, packet)) {
-      if (typeof values[getFieldInfo(typeArgs.type).type] === "function")
-        return values[getFieldInfo(typeArgs.type).type](getFieldInfo(typeArgs.type).typeArgs, packet);
+  'switch': function(typeArgs, packet) {
+    var i = typeArgs.fields[getField(typeArgs.compareTo, packet)];
+    if (typeof i === "undefined")
+      return getValue(typeArgs.default, packet);
     else
-        return values[getFieldInfo(typeArgs.type).type];
-    }
-  }
+      return getValue(i, packet);
+  },
 };
 
+function getValue(_type, packet) {
+  var fieldInfo = getFieldInfo(_type);
+  if (typeof values[fieldInfo.type] === "function")
+    return values[fieldInfo.type](fieldInfo.typeArgs, packet);
+  else if (values[fieldInfo.type] !== "undefined")
+    return values[fieldInfo.type];
+  else if (fieldInfo.type !== "void")
+    throw new Error("No value for type " + fieldInfo.type);
+}
+
 describe("packets", function() {
   var client, server, serverClient;
   before(function(done) {
@@ -188,14 +183,7 @@ describe("packets", function() {
     // empty object uses default values
     var packet = {};
     packetInfo.forEach(function(field) {
-      var fieldVal = values[getFieldInfo(field.type).type];
-      if(typeof fieldVal === "undefined") {
-        throw new Error("No value for type " + field.type);
-      }
-      if(typeof fieldVal === "function") {
-        fieldVal = fieldVal(getFieldInfo(field.type).typeArgs, packet);
-      }
-      packet[field.name] = fieldVal;
+      packet[field.name] = getValue(field.type, packet);
     });
     if(toServer) {
       serverClient.once([state, packetId], function(receivedPacket) {