test.py: add test for halving calculator

examples/halving-calculator.py

@@ -2,15 +2,28 @@
 
 # Demonstrates use of the MMGen asyncio/aiohttp JSON-RPC interface
 # https://github.com/mmgen/mmgen
-# Requires a running Bitcoin Core node
-# If necessary, invoke with --rpc-host/--rpc-port/--rpc-user/--rpc-password
-# Specify aiohttp backend with --rpc-backend=aiohttp (Linux only)
 
 import time
 from decimal import Decimal
 from mmgen.common import *
 
-opts.init()
+opts.init({
+	'text': {
+		'desc': 'Estimate date of next Bitcoin halving',
+		'usage':'[opts]',
+		'options': """
+-h, --help          Print this help message
+--, --longhelp      Print help message for long options (common options)
+-s, --sample-size=N Specify sample block range for block discovery time
+                    estimate
+""",
+	'notes': """
+Requires a running Bitcoin Core node
+If necessary, invoke with --rpc-host/--rpc-port/--rpc-user/--rpc-password
+Specify aiohttp backend with --rpc-backend=aiohttp (Linux only)
+"""
+	}
+})
 
 HalvingInterval = 210000 # src/chainparams.cpp
 
@@ -36,7 +49,7 @@ async def main():
 
 	tip = await c.call('getblockcount')
 	remaining = HalvingInterval - tip % HalvingInterval
-	sample_size = max(remaining,144)
+	sample_size = int(opt.sample_size) if opt.sample_size else max(remaining,144)
 
 	# aiohttp backend will perform these two calls concurrently:
 	cur,old = await c.gathered_call('getblockstats',((tip,),(tip - sample_size,)))

test/test_py_d/ts_regtest.py

@@ -143,6 +143,7 @@ class TestSuiteRegtest(TestSuiteBase,TestSuiteShared):
 	cmd_group = (
 		('setup',                    'regtest (Bob and Alice) mode setup'),
 		('current_user',             'current user'),
+		('halving_calculator_bob',   'halving calculator (Bob)'),
 		('walletgen_bob',            'wallet generation (Bob)'),
 		('walletgen_alice',          'wallet generation (Alice)'),
 		('addrgen_bob',              'address generation (Bob)'),
@@ -283,6 +284,12 @@ class TestSuiteRegtest(TestSuiteBase,TestSuiteShared):
 		t.expect('Bob')
 		return t
 
+	def halving_calculator_bob(self):
+		t = self.spawn('halving-calculator.py',['--bob','--sample-size=144'],cmd_dir='examples')
+		t.expect('time until halving')
+		t.read()
+		return t
+
 	def walletgen(self,user):
 		t = self.spawn('mmgen-walletgen',['-q','-r0','-p1','--'+user])
 		t.passphrase_new('new '+dfl_wcls.desc,rt_pw)