Merge pull request keichi#55 from keichi/amorri40-master

Allow Parent parser attributes in choice

Author: keichi

lib/binary_parser.js

@@ -607,14 +607,16 @@ Parser.prototype.generateChoiceCase = function(ctx, varName, type) {
     } else if (type instanceof Parser) {
         ctx.pushPath(varName);
         type.generate(ctx);
-        ctx.popPath();
+        ctx.popPath(varName);
     }
 };
 
 Parser.prototype.generateChoice = function(ctx) {
     var tag = ctx.generateOption(this.options.tag);
-
-    ctx.pushCode('{0} = {};', ctx.generateVariable(this.varName));
+    if (this.varName)
+    {
+        ctx.pushCode('{0} = {};', ctx.generateVariable(this.varName));
+    }
     ctx.pushCode('switch({0}) {', tag);
     Object.keys(this.options.choices).forEach(function(tag) {
         var type = this.options.choices[tag];
@@ -638,7 +640,7 @@ Parser.prototype.generateNest = function(ctx) {
         ctx.pushCode('{0} = {};', nestVar);
         ctx.pushPath(this.varName);
         this.options.type.generate(ctx);
-        ctx.popPath();
+        ctx.popPath(this.varName);
     } else if (aliasRegistry[this.options.type]) {
         var tempVar = ctx.generateTmpVariable();
         ctx.pushCode('var {0} = {1}(offset);', tempVar, FUNCTION_PREFIX + this.options.type);

lib/context.js

@@ -37,7 +37,7 @@ Context.prototype.generateOption = function(val) {
         case 'string':
             return this.generateVariable(val);
         case 'function':
-            return '(' + val + ').call(' + this.generateVariable() + ')';
+            return '(' + val + ').call(' + this.generateVariable() + ', vars)';
     }
 };
 
@@ -63,11 +63,17 @@ Context.prototype.pushCode = function() {
 };
 
 Context.prototype.pushPath = function(name) {
-    this.scopes[this.scopes.length - 1].push(name);
+    if (name)
+    {
+    	this.scopes[this.scopes.length - 1].push(name);
+    }
 };
 
-Context.prototype.popPath = function() {
-    this.scopes[this.scopes.length - 1].pop();
+Context.prototype.popPath = function(name) {
+    if (name)
+   { 
+   	this.scopes[this.scopes.length - 1].pop();
+   }
 };
 
 Context.prototype.pushScope = function(name) {

test/composite_parser.js

@@ -321,6 +321,33 @@ describe('Composite parser', function(){
                 } ]
             });
         });
+
+        it('should allow parent parser attributes as choice key', function() {
+            var ChildParser = Parser.start()
+                .choice('data', {
+                    tag: function(vars) {
+                        return vars.version;
+                    },
+                    choices: {
+                        1: Parser.start().uint8('v1'),
+                        2: Parser.start().uint16('v2'),
+                    }
+                });
+
+            var ParentParser = Parser.start()
+                .uint8('version')
+                .nest('child', { type: ChildParser });
+
+            var buffer = new Buffer([0x1, 0x2]);
+            assert.deepEqual(ParentParser.parse(buffer), {
+                version: 1, child: { data: { v1: 2 } }
+            });
+
+            buffer = new Buffer([0x2, 0x3, 0x4]);
+            assert.deepEqual(ParentParser.parse(buffer), {
+                version: 2, child: { data: { v2: 0x0304 } }
+            });
+        });
     });
 
     describe('Choice parser', function() {