[KMS-ETH]- Modules to work with a token

nkms_eth/blockchain.py

@@ -4,9 +4,14 @@ import nkms_eth
 from os.path import dirname, join, abspath
 
 DEFAULT_NETWORK = 'mainnetrpc'
+TIMEOUT = 60
 _project = threading.local()
 
 
+# TODO XXX registrar.json is created in a current directory!
+# we should instead create all new configs in ~/.local
+
+
 def project():
     # Hardcoded the config for the project
     # It will read user-specific configs also which may override it
@@ -16,15 +21,24 @@ def project():
     return _project.project
 
 
-def chain(name=DEFAULT_NETWORK):
+def get_chain(name=None):
+    return project().get_chain(name or DEFAULT_NETWORK)
+
+
+def chain(name=None):
     if not hasattr(_project, 'chain'):
-        _project.chain = project().get_chain(name).__enter__()
+        _project.chain = get_chain(name).__enter__()
     return _project.chain
 
 
 def disconnect():
     _project.chain.__exit__(None, None, None)
-    delattr(_project, 'chain')
+    if hasattr(_project, 'project'):
+        delattr(_project, 'project')
+    if hasattr(_project, 'chain'):
+        delattr(_project, 'chain')
+    if hasattr(_project, 'web3'):
+        delattr(_project, 'web3')
 
 
 def web3():

nkms_eth/deploy.py

@@ -1,11 +0,0 @@
-def create_tokens():
-    pass
-
-
-def deploy_escrow():
-    pass
-
-
-if __name__ == '__main__':
-    create_tokens()
-    deploy_escrow()

nkms_eth/token.py

@@ -0,0 +1,41 @@
+from nkms_eth import blockchain
+
+CONTRACT_NAME = 'HumanStandardToken'  # TODO this should be NuCypher's class
+SUBDIGITS = 6
+M = 10 ** SUBDIGITS
+PREMINE = int(1e9) * M
+SATURATION = int(1e10) * M
+
+
+def create():
+    """
+    Creates a contract with tokens and returns it.
+    If it was already created, just returns the already existing contract
+
+    :returns:   Token contract object
+    """
+    chain = blockchain.chain()
+    web3 = chain.web3
+    creator = web3.eth.accounts[0]  # TODO: make it possible to override
+
+    token, tx = chain.provider.get_or_deploy_contract(
+        CONTRACT_NAME, deploy_args=[
+            PREMINE, SATURATION, 'NuCypher KMS', SUBDIGITS, 'KMS'],
+        deploy_transaction={
+            'from': creator})
+    if tx:
+        chain.wait.for_receipt(tx, timeout=blockchain.TIMEOUT)
+
+    return token
+
+
+def get(name=CONTRACT_NAME):
+    """
+    Gets an existing contract or returns an error
+    """
+    return blockchain.chain().provider.get_contract(name)
+
+
+if __name__ == '__main__':
+    create()
+    get()

tests/conftest.py

@@ -4,5 +4,11 @@ from nkms_eth import blockchain
 
 @pytest.fixture()
 def project():
-    blockchain.DEFAULT_NETWORK = 'tester'
     return blockchain.project()
+
+
+@pytest.fixture()
+def chain():
+    blockchain.DEFAULT_NETWORK = 'tester'
+    yield blockchain.chain()
+    blockchain.disconnect()

tests/test_blockchain.py

@@ -0,0 +1,7 @@
+from nkms_eth import blockchain
+
+
+def test_chain(chain):
+    assert blockchain.DEFAULT_NETWORK == 'tester'
+    web3 = blockchain.web3()
+    assert web3.eth.blockNumber >= 0

tests/test_token_module.py

@@ -0,0 +1,18 @@
+from pytest import raises
+from populus.contracts.exceptions import NoKnownAddress
+
+from nkms_eth import token
+
+
+def test_create(chain):
+    t = token.create()
+    assert len(t.address) == 42
+
+
+def test_get(chain):
+    with raises(NoKnownAddress):
+        token.get()
+
+    token.create()
+    t = token.get()
+    assert len(t.address) == 42