Safely encode yaql expressions to support unicode expressions

Before unicode in yaql would cause a UnicodeEncodeError.
Now YaqlExpression should behave better with unicode input.

Change-Id: I3bbb018d7bd78cbf66c4190ef4c0b7d7e3baa03c
Closes-Bug: #1361169

murano/dsl/yaql_expression.py

@@ -15,6 +15,8 @@
 import re
 import types
 
+from oslo_utils import encodeutils
+
 import yaql
 import yaql.exceptions
 import yaql.expressions
@@ -23,7 +25,7 @@ import yaql.expressions
 class YaqlExpression(object):
     def __init__(self, expression):
         if isinstance(expression, types.StringTypes):
-            self._expression = str(expression)
+            self._expression = encodeutils.safe_encode(expression)
             self._parsed_expression = yaql.parse(self._expression)
             self._file_position = None
         elif isinstance(expression, YaqlExpression):

murano/tests/unit/test_engine.py

@@ -1,3 +1,4 @@
+# coding: utf-8
 # Copyright (c) 2014 Mirantis Inc.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -164,6 +165,19 @@ class TestYaqlExpression(base.MuranoTestCase):
 
         self.assertEqual('string', yaql_expr.expression)
 
+    def test_unicode_expression(self):
+        yaql_expr = yaql_expression.YaqlExpression(u"'yaql ♥ unicode'")
+
+        self.assertEqual(u"'yaql ♥ unicode'".encode('utf-8'),
+                         yaql_expr.expression)
+
+    def test_unicode_expression_expression(self):
+        yaql_expr = yaql_expression.YaqlExpression(u"'yaql ♥ unicode'")
+        yaql_expr2 = yaql_expression.YaqlExpression(yaql_expr)
+
+        self.assertEqual(u"'yaql ♥ unicode'".encode('utf-8'),
+                         yaql_expr2.expression)
+
     def test_evaluate_calls(self):
         string = 'string'
         expected_calls = [mock.call(string),