test: Add test for RPC named arguments

Add RPC testcase for RPC named arguments.

qa/pull-tester/rpc-tests.py

@@ -151,6 +151,7 @@
     'signmessages.py',
     'nulldummy.py',
     'import-rescan.py',
+    'rpcnamedargs.py',
 ]
 if ENABLE_ZMQ:
     testScripts.append('zmq_test.py')

qa/rpc-tests/rpcnamedargs.py

@@ -0,0 +1,52 @@
+#!/usr/bin/env python3
+# Copyright (c) 2016 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+from decimal import Decimal
+
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.authproxy import JSONRPCException
+from test_framework.util import (
+    assert_equal,
+    assert_raises_jsonrpc,
+    assert_is_hex_string,
+    assert_is_hash_string,
+    start_nodes,
+    connect_nodes_bi,
+)
+
+
+class NamedArgumentTest(BitcoinTestFramework):
+    """
+    Test named arguments on RPC calls.
+    """
+
+    def __init__(self):
+        super().__init__()
+        self.setup_clean_chain = False
+        self.num_nodes = 1
+
+    def setup_network(self, split=False):
+        self.nodes = start_nodes(self.num_nodes, self.options.tmpdir)
+        self.is_network_split = False
+        self.sync_all()
+
+    def run_test(self):
+        node = self.nodes[0]
+        h = node.help(command='getinfo')
+        assert(h.startswith('getinfo\n'))
+
+        assert_raises_jsonrpc(-8, node.help, random='getinfo')
+
+        h = node.getblockhash(index=0)
+        node.getblock(hash=h)
+
+        assert_equal(node.echo(), [])
+        assert_equal(node.echo(arg0=0,arg9=9), [0] + [None]*8 + [9])
+        assert_equal(node.echo(arg1=1), [None, 1])
+        assert_equal(node.echo(arg9=None), [None]*10)
+        assert_equal(node.echo(arg0=0,arg3=3,arg9=9), [0] + [None]*2 + [3] + [None]*5 + [9])
+
+if __name__ == '__main__':
+    NamedArgumentTest().main()

qa/rpc-tests/test_framework/util.py

@@ -546,6 +546,18 @@ def assert_raises_message(exc, message, fun, *args, **kwds):
     else:
         raise AssertionError("No exception raised")
 
+def assert_raises_jsonrpc(code, fun, *args, **kwds):
+    '''Check for specific JSONRPC exception code'''
+    try:
+        fun(*args, **kwds)
+    except JSONRPCException as e:
+        if e.error["code"] != code:
+            raise AssertionError("Unexpected JSONRPC error code %i" % e.error["code"])
+    except Exception as e:
+        raise AssertionError("Unexpected exception raised: "+type(e).__name__)
+    else:
+        raise AssertionError("No exception raised")
+
 def assert_is_hex_string(string):
     try:
         int(string, 16)