Fix issue keichi#16 where string parser was broken

iwinks · Jun 5, 2015 · cc53ac3 · cc53ac3
1 parent e401454
commit cc53ac3
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Showing 2 changed files with 47 additions and 13 deletions.
diff --git a/lib/binary_parser.js b/lib/binary_parser.js
@@ -108,7 +108,10 @@ Parser.prototype.skip = function(length, options) {
 
 Parser.prototype.string = function(varName, options) {
     if (!options.zeroTerminated && !options.length) {
-        throw new Error('Length option of string is not defined.');
+        throw new Error('Neiter length nor zeroTerminated is defined for string.');
+    }
+    if (options.stripNull && !options.length) {
+        throw new Error('Length must be defined if stripNull is defined.');
     }
     options.encoding = options.encoding || 'utf8';
 
@@ -398,30 +401,40 @@ Parser.prototype.generateSkip = function(ctx) {
 };
 
 Parser.prototype.generateString = function(ctx) {
-    if(this.options.length) {
-        var name = ctx.generateVariable(this.varName);
+    var name = ctx.generateVariable(this.varName);
+    var start = ctx.generateTmpVariable();
+
+    if (this.options.length && this.options.zeroTerminated) {
+        ctx.pushCode('var {0} = offset;', start);
+        ctx.pushCode('while(buffer.readUInt8(offset++) !== 0 && offset - {0}  < {1});',
+            start,
+            this.options.length
+        );
+        ctx.pushCode('{0} = buffer.toString(\'{1}\', {2}, offset - {2} < {3} ? offset - 1 : offset);',
+            name,
+            this.options.encoding,
+            start,
+            this.options.length
+        );
+    } else if(this.options.length) {
         ctx.pushCode('{0} = buffer.toString(\'{1}\', offset, offset + {2});',
                             name,
                             this.options.encoding,
                             ctx.generateOption(this.options.length)
                         );
-        if(this.options.stripNull)
-        {
-            ctx.pushCode('{0} = {0}.replace(/\0/g, \'\')', name);
-        }
         ctx.pushCode('offset += {0};', ctx.generateOption(this.options.length));
-    }
-    else {
-        var start = ctx.generateTmpVariable();
-
+    } else if (this.options.zeroTerminated) {
         ctx.pushCode('var {0} = offset;', start);
         ctx.pushCode('while(buffer.readUInt8(offset++) !== 0);');
         ctx.pushCode('{0} = buffer.toString(\'{1}\', {2}, offset - 1);',
-            ctx.generateVariable(this.varName),
+            name,
             this.options.encoding,
             start
         );
     }
+    if(this.options.stripNull) {
+        ctx.pushCode('{0} = {0}.replace(/\\x00+$/g, \'\')', name);
+    }
 };
 
 Parser.prototype.generateBuffer = function(ctx) {
@@ -536,7 +549,7 @@ Parser.prototype.generateFormatter = function(ctx, varName, formatter) {
     if (typeof formatter === 'function') {
         ctx.pushCode('{0} = ({1}).call(this, {0});', varName, formatter);
     }
-}
+};
 
 Parser.prototype.isInteger = function() {
     return !!this.type.match(/U?Int[8|16|32][BE|LE]?|Bit\d+/);

diff --git a/test/primitive_parser.js b/test/primitive_parser.js
@@ -232,6 +232,27 @@ describe('Primitive parser', function(){
 
             assert.deepEqual(parser.parse(buffer), {msg: 'hello, world'});
         });
+        it('should parser zero terminated fixed-length string', function() {
+            var buffer = new Buffer('abc\u0000defghij\u0000');
+            var parser = Parser.start()
+                .string('a', {length: 5, zeroTerminated: true})
+                .string('b', {length: 5, zeroTerminated: true})
+                .string('c', {length: 5, zeroTerminated: true})
+
+            assert.deepEqual(parser.parse(buffer), {
+                a: 'abc',
+                b: 'defgh',
+                c: 'ij'
+            });
+        });
+        it('should strip trailing null characters', function() {
+            var buffer = new Buffer('746573740000', 'hex');
+            var parser1 = Parser.start().string('str', {length: 7, stripNull: false});
+            var parser2 = Parser.start().string('str', {length: 7, stripNull: true});
+
+            assert.equal(parser1.parse(buffer).str, 'test\u0000\u0000');
+            assert.equal(parser2.parse(buffer).str, 'test');
+        });
     });
 
     describe('Buffer parser', function() {