Merge pull request #124 from scottbelden/is_promotable

add is_promotable api

iota/api.py

@@ -9,6 +9,7 @@
 from iota.adapter import BaseAdapter, resolve_adapter
 from iota.commands import BaseCommand, CustomCommand, core, \
   discover_commands, extended
+from iota.commands.extended.helpers import Helpers
 from iota.crypto.addresses import AddressGenerator
 from iota.crypto.types import Seed
 from six import with_metaclass
@@ -440,6 +441,7 @@ def __init__(self, adapter, seed=None, testnet=False):
     super(Iota, self).__init__(adapter, testnet)
 
     self.seed = Seed(seed) if seed else Seed.random()
+    self.helpers = Helpers(self)
 
   def broadcast_and_store(self, trytes):
     # type: (Iterable[TransactionTrytes]) -> dict

iota/commands/extended/helpers.py

@@ -0,0 +1,18 @@
+class Helpers(object):
+  """
+  Adds additional helper functions that aren't part of the core or extended
+  API.
+  """
+
+  def __init__(self, api):
+    self.api = api
+
+  def is_promotable(self, tail):
+    # type: (TransactionHash) -> bool
+    """
+    Determines if a tail transaction is promotable.
+
+    :param tail:
+      Transaction hash. Must be a tail transaction.
+    """
+    return self.api.check_consistency(tails=[tail])['state']

test/commands/extended/helpers_test.py

@@ -0,0 +1,45 @@
+# coding=utf-8
+from __future__ import absolute_import, division, print_function, \
+  unicode_literals
+
+from unittest import TestCase
+
+from iota import Iota, TransactionHash
+from iota.adapter import MockAdapter
+
+
+class HelpersTestCase(TestCase):
+  def setUp(self):
+    super(HelpersTestCase, self).setUp()
+
+    self.api = api = Iota('mock://')
+    self.api.adapter = MockAdapter()
+
+    # noinspection SpellCheckingInspection
+    self.transaction = (
+      'TESTVALUE9DONTUSEINPRODUCTION99999KPZOTR'
+      'VDB9GZDJGZSSDCBIX9QOK9PAV9RMDBGDXLDTIZTWQ'
+    )
+
+  def test_positive_is_promotable(self):
+    """
+    Transaction is promotable
+    """
+
+    self.api.adapter.seed_response('checkConsistency', {
+      'state': True,
+    })
+
+    self.assertTrue(self.api.helpers.is_promotable(tail=self.transaction))
+
+  def test_negative_is_promotable(self):
+    """
+    Transaction is not promotable
+    """
+
+    self.api.adapter.seed_response('checkConsistency', {
+      'state': False,
+      'info': 'Inconsistent state',
+    })
+
+    self.assertFalse(self.api.helpers.is_promotable(tail=self.transaction))