Allow empty proof spec for tokens api

apps/cic-eth/cic_eth/api/api_task.py

@@ -118,7 +118,11 @@ class Api(ApiBase):
         if proof == None:
             logg.debug('looking up tokens without external proof check: {}'.format(','.join(token_symbols)))
             proof = ''
-        proof = Api.to_v_list(proof, len(token_symbols)) 
+
+        l = len(token_symbols)
+        if len(proof) == 0:
+            l = 0 
+        proof = Api.to_v_list(proof, l)
 
         chain_spec_dict = self.chain_spec.asdict()
 

apps/cic-eth/tests/task/api/test_app_noncritical.py

@@ -41,6 +41,8 @@ def test_default_token(
 
 
 def test_to_v_list():
+    assert Api.to_v_list('', 0) == []
+    assert Api.to_v_list([], 0) == []
     assert Api.to_v_list('foo', 1) == [['foo']]
     assert Api.to_v_list(['foo'], 1) == [['foo']]
     assert Api.to_v_list(['foo', 'bar'], 2) == [['foo'], ['bar']]
@@ -95,6 +97,40 @@ def test_token_single(
     assert r[0]['address'] == strip_0x(foo_token)
 
 
+def test_tokens_noproof(
+        default_chain_spec,
+        foo_token,
+        bar_token,
+        token_registry,
+        register_tokens,
+        register_lookups,
+        cic_registry,
+        init_database,
+        init_celery_tasks,
+        custodial_roles,
+        foo_token_declaration,
+        bar_token_declaration,
+        celery_session_worker,
+        ):
+
+    api = Api(str(default_chain_spec), queue=None, callback_param='foo')     
+
+    t = api.tokens(['FOO'], proof=[])
+    r = t.get()
+    assert len(r) == 1
+    assert r[0]['address'] == strip_0x(foo_token)
+
+    t = api.tokens(['FOO'], proof='')
+    r = t.get()
+    assert len(r) == 1
+    assert r[0]['address'] == strip_0x(foo_token)
+
+    t = api.tokens(['FOO'], proof=None)
+    r = t.get()
+    assert len(r) == 1
+    assert r[0]['address'] == strip_0x(foo_token)
+
+
 def test_tokens(
         default_chain_spec,
         foo_token,