Add support for UniqueIdentifier (GUID) in result set rows.

Fixes #10

lib/token/data-type.coffee

@@ -40,6 +40,10 @@ TYPE =
     name: 'BigInt'
 
   # Variable-length types
+  0x24:
+    type: 'GUIDN'
+    name: 'UniqueIdentifierN'
+    dataLengthLength: 1
   0x26:
     type: 'INTN'
     name: 'IntN'
@@ -99,11 +103,6 @@ TYPE =
 
   ###
   # Variable-length types
-  GUIDTYPE:
-    id: 0x24
-    variableLength: true
-    name: 'UniqueIdentifier'
-    dataLengthLength: 1
   GUIDTYPE:             0x24  # UniqueIdentifier
   DECIMALTYPE:          0x37  # Decimal (legacy support)
   NUMERICTYPE:          0x3F  # Numeric (legacy support)

lib/token/row-token-parser.coffee

@@ -137,6 +137,14 @@ parser = (buffer, columnsMetaData) ->
 
           value *= sign
           value /= Math.pow(10, columnMetaData.scale)
+      when 'UniqueIdentifierN'
+        switch dataLength
+          when 0
+            value = null
+          when 0x10
+            value = buffer.readArray(0x10)
+          else
+            throw new Error(sprintf('Unsupported guid size %d at offset 0x%04X', dataLength - 1, buffer.position))
       else
         throw new Error(sprintf('Unrecognised column type %s at offset 0x%04X', type.name, buffer.position))
         break

test/integration/datatypes-in-results-test.coffee

@@ -133,6 +133,14 @@ exports.nchar = (test) ->
 exports.ncharNull = (test) ->
   execSql(test, "select cast(null as nchar(5))", null)
 
+exports.guid = (test) ->
+  execSql(test, "select cast('01234567-89AB-CDEF-0123-456789ABCDEF' as uniqueidentifier)", [
+    0x67, 0x45, 0x23, 0x01, 0xAB, 0x89, 0xEF, 0xCD,
+    0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF
+  ])
+
+exports.guidNull = (test) ->
+  execSql(test, "select cast(null as uniqueidentifier)", null)
 
 execSql = (test, sql, expectedValue) ->
   test.expect(2)

test/unit/token/row-token-parser-test.coffee

@@ -339,6 +339,28 @@ module.exports.intN = (test) ->
 
   test.done()
 
+module.exports.guidN = (test) ->
+  colMetaData = [
+    {type: dataTypeByName.UniqueIdentifierN}
+    {type: dataTypeByName.UniqueIdentifierN}
+  ]
+
+  buffer = new WritableTrackingBuffer(0, 'ucs2')
+  buffer.writeBuffer(new Buffer([
+    0,
+    16, 0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef,0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef
+  ]))
+  #console.log(buffer.data)
+
+  token = parser(new ReadableTrackingBuffer(buffer.data, 'ucs2'), colMetaData)
+  #console.log(token)
+
+  test.strictEqual(token.columns.length, 2)
+  test.strictEqual(token.columns[0].value, null)
+  test.deepEqual([0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef,0x01,0x23,0x45,0x67,0x89,0xab,0xcd,0xef], token.columns[1].value)
+
+  test.done()
+
 module.exports.floatN = (test) ->
   colMetaData = [
     {type: dataTypeByName.FloatN}