Merge "Add 't', 'y', and `strict` to `bool_from_string`"

2 files changed, 92 insertions, 14 deletions

diff --git a/openstack/common/strutils.py b/openstack/common/strutils.py
index d6dfb13..6d227c6 100644
--- a/openstack/common/strutils.py
+++ b/openstack/common/strutils.py
@@ -21,6 +21,12 @@ System-level utilities and helper functions.
 
 import sys
 
+from openstack.common.gettextutils import _
+
+
+TRUE_STRINGS = ('1', 't', 'true', 'on', 'y', 'yes')
+FALSE_STRINGS = ('0', 'f', 'false', 'off', 'n', 'no')
+
 
 def int_from_bool_as_string(subject):
     """
@@ -37,27 +43,38 @@ def int_from_bool_as_string(subject):
     return bool_from_string(subject) and 1 or 0
 
 
-def bool_from_string(subject):
+def bool_from_string(subject, strict=False):
     """
     Interpret a string as a boolean.
 
-    Any string value in:
-
-        ('True', 'true', 'On', 'on', 'Yes', 'yes', '1')
+    A case-insensitive match is performed such that strings matching 't',
+    'true', 'on', 'y', 'yes', or '1' are considered True and, when
+    `strict=False`, anything else is considered False.
 
-    is interpreted as a boolean True.
+    Useful for JSON-decoded stuff and config file parsing.
 
-    Useful for JSON-decoded stuff and config file parsing
+    If `strict=True`, unrecognized values, including None, will raise a
+    ValueError which is useful when parsing values passed in from an API call.
+    Strings yielding False are 'f', 'false', 'off', 'n', 'no', or '0'.
     """
-    try:
-        # True or 1 or '1' -> True
-        # False or < 1 or > 1 or '0' -> False
-        return int(subject) == 1
-    except TypeError:
-        # None -> False
+    if not isinstance(subject, basestring):
+        subject = str(subject)
+
+    lowered = subject.strip().lower()
+
+    if lowered in TRUE_STRINGS:
+        return True
+    elif lowered in FALSE_STRINGS:
+        return False
+    elif strict:
+        acceptable = ', '.join(
+            "'%s'" % s for s in sorted(TRUE_STRINGS + FALSE_STRINGS))
+        msg = _("Unrecognized value '%(val)s', acceptable values are:"
+                " %(acceptable)s") % {'val': subject,
+                                      'acceptable': acceptable}
+        raise ValueError(msg)
+    else:
         return False
-    except ValueError:
-        return subject.strip().lower() in ('true', 'on', 'yes')
 
 
 def safe_decode(text, incoming=None, errors='strict'):
diff --git a/tests/unit/test_strutils.py b/tests/unit/test_strutils.py
index b0af958..bad50c8 100644
--- a/tests/unit/test_strutils.py
+++ b/tests/unit/test_strutils.py
@@ -1,3 +1,4 @@
+# -*- coding: utf-8 -*-
 # vim: tabstop=4 shiftwidth=4 softtabstop=4
 
 # Copyright 2011 OpenStack Foundation.
@@ -37,6 +38,10 @@ class StrUtilsTest(utils.BaseTestCase):
         self.assertTrue(strutils.bool_from_string(c('YES')))
         self.assertTrue(strutils.bool_from_string(c('yEs')))
         self.assertTrue(strutils.bool_from_string(c('1')))
+        self.assertTrue(strutils.bool_from_string(c('T')))
+        self.assertTrue(strutils.bool_from_string(c('t')))
+        self.assertTrue(strutils.bool_from_string(c('Y')))
+        self.assertTrue(strutils.bool_from_string(c('y')))
 
         self.assertFalse(strutils.bool_from_string(c('false')))
         self.assertFalse(strutils.bool_from_string(c('FALSE')))
@@ -47,9 +52,15 @@ class StrUtilsTest(utils.BaseTestCase):
         self.assertFalse(strutils.bool_from_string(c('42')))
         self.assertFalse(strutils.bool_from_string(c(
                          'This should not be True')))
+        self.assertFalse(strutils.bool_from_string(c('F')))
+        self.assertFalse(strutils.bool_from_string(c('f')))
+        self.assertFalse(strutils.bool_from_string(c('N')))
+        self.assertFalse(strutils.bool_from_string(c('n')))
 
         # Whitespace should be stripped
+        self.assertTrue(strutils.bool_from_string(c(' 1 ')))
         self.assertTrue(strutils.bool_from_string(c(' true ')))
+        self.assertFalse(strutils.bool_from_string(c(' 0 ')))
         self.assertFalse(strutils.bool_from_string(c(' false ')))
 
     def test_bool_from_string(self):
@@ -57,6 +68,14 @@ class StrUtilsTest(utils.BaseTestCase):
 
     def test_unicode_bool_from_string(self):
         self._test_bool_from_string(six.text_type)
+        self.assertFalse(strutils.bool_from_string(u'使用', strict=False))
+
+        exc = self.assertRaises(ValueError, strutils.bool_from_string,
+                                u'使用', strict=True)
+        expected_msg = (u"Unrecognized value '使用', acceptable values are:"
+                        u" '0', '1', 'f', 'false', 'n', 'no', 'off', 'on',"
+                        u" 't', 'true', 'y', 'yes'")
+        self.assertEqual(expected_msg, unicode(exc))
 
     def test_other_bool_from_string(self):
         self.assertFalse(strutils.bool_from_string(None))
@@ -69,6 +88,48 @@ class StrUtilsTest(utils.BaseTestCase):
         self.assertFalse(strutils.bool_from_string(0))
         self.assertFalse(strutils.bool_from_string(2))
 
+    def test_strict_bool_from_string(self):
+        # None isn't allowed in strict mode
+        exc = self.assertRaises(ValueError, strutils.bool_from_string, None,
+                                strict=True)
+        expected_msg = ("Unrecognized value 'None', acceptable values are:"
+                        " '0', '1', 'f', 'false', 'n', 'no', 'off', 'on',"
+                        " 't', 'true', 'y', 'yes'")
+        self.assertEqual(expected_msg, str(exc))
+
+        # Unrecognized strings aren't allowed
+        self.assertFalse(strutils.bool_from_string('Other', strict=False))
+        exc = self.assertRaises(ValueError, strutils.bool_from_string, 'Other',
+                                strict=True)
+        expected_msg = ("Unrecognized value 'Other', acceptable values are:"
+                        " '0', '1', 'f', 'false', 'n', 'no', 'off', 'on',"
+                        " 't', 'true', 'y', 'yes'")
+        self.assertEqual(expected_msg, str(exc))
+
+        # Unrecognized numbers aren't allowed
+        exc = self.assertRaises(ValueError, strutils.bool_from_string, 2,
+                                strict=True)
+        expected_msg = ("Unrecognized value '2', acceptable values are:"
+                        " '0', '1', 'f', 'false', 'n', 'no', 'off', 'on',"
+                        " 't', 'true', 'y', 'yes'")
+        self.assertEqual(expected_msg, str(exc))
+
+        # False-like values are allowed
+        self.assertFalse(strutils.bool_from_string('f', strict=True))
+        self.assertFalse(strutils.bool_from_string('false', strict=True))
+        self.assertFalse(strutils.bool_from_string('off', strict=True))
+        self.assertFalse(strutils.bool_from_string('n', strict=True))
+        self.assertFalse(strutils.bool_from_string('no', strict=True))
+        self.assertFalse(strutils.bool_from_string('0', strict=True))
+
+        self.assertTrue(strutils.bool_from_string('1', strict=True))
+
+        # Avoid font-similarity issues (one looks like lowercase-el, zero like
+        # oh, etc...)
+        for char in ('O', 'o', 'L', 'l', 'I', 'i'):
+            self.assertRaises(ValueError, strutils.bool_from_string, char,
+                              strict=True)
+
     def test_int_from_bool_as_string(self):
         self.assertEqual(1, strutils.int_from_bool_as_string(True))
         self.assertEqual(0, strutils.int_from_bool_as_string(False))