[test] Add support for custom arguments to TestNodeCLI

test/functional/test_framework/test_node.py

@@ -155,8 +155,16 @@ class TestNodeCLI():
     """Interface to bitcoin-cli for an individual node"""
 
     def __init__(self, binary, datadir):
+        self.args = []
         self.binary = binary
         self.datadir = datadir
+        self.input = None
+
+    def __call__(self, *args, input=None):
+        # TestNodeCLI is callable with bitcoin-cli command-line args
+        self.args = [str(arg) for arg in args]
+        self.input = input
+        return self
 
     def __getattr__(self, command):
         def dispatcher(*args, **kwargs):
@@ -169,9 +177,9 @@ class TestNodeCLI():
         pos_args = [str(arg) for arg in args]
         named_args = [str(key) + "=" + str(value) for (key, value) in kwargs.items()]
         assert not (pos_args and named_args), "Cannot use positional arguments and named arguments in the same bitcoin-cli call"
-        p_args = [self.binary, "-datadir=" + self.datadir]
+        p_args = [self.binary, "-datadir=" + self.datadir] + self.args
         if named_args:
             p_args += ["-named"]
         p_args += [command] + pos_args + named_args
-        cli_output = subprocess.check_output(p_args, universal_newlines=True)
+        cli_output = subprocess.check_output(p_args, input=self.input, universal_newlines=True)
         return json.loads(cli_output, parse_float=decimal.Decimal)