[tests] don't override __init__() in individual tests

Almost all test scripts currently need to override the __init__()
method. When they do that they need to call into super().__init__() as
the base class does some generic initialization.

This commit makes the base class __init__() call into set_test_params()
method. Individual test cases can override set_test_params() to setup
their test parameters.

Author: jnewbery

test/functional/README.md

@@ -24,8 +24,8 @@ don't have test cases for.
 - Use a module-level docstring to describe what the test is testing, and how it
   is testing it.
 - When subclassing the BitcoinTestFramwork, place overrides for the
-  `__init__()`, and `setup_xxxx()` methods at the top of the subclass, then
-  locally-defined helper methods, then the `run_test()` method.
+  `set_test_params()`, `add_options()` and `setup_xxxx()` methods at the top of
+  the subclass, then locally-defined helper methods, then the `run_test()` method.
 
 #### General test-writing advice
 
@@ -36,7 +36,7 @@ don't have test cases for.
 - Avoid stop-starting the nodes multiple times during the test if possible. A
   stop-start takes several seconds, so doing it several times blows up the
   runtime of the test.
-- Set the `self.setup_clean_chain` variable in `__init__()` to control whether
+- Set the `self.setup_clean_chain` variable in `set_test_params()` to control whether
   or not to use the cached data directories. The cached data directories
   contain a 200-block pre-mined blockchain and wallets for four nodes. Each node
   has 25 mature blocks (25x50=1250 BTC) in its wallet.

test/functional/abandonconflict.py

@@ -14,10 +14,8 @@
 from test_framework.util import *
 
 class AbandonConflictTest(BitcoinTestFramework):
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 2
-        self.setup_clean_chain = False
         self.extra_args = [["-minrelaytxfee=0.00001"], []]
 
     def run_test(self):

test/functional/assumevalid.py

@@ -54,8 +54,7 @@ def send_header_for_blocks(self, new_blocks):
         self.send_message(headers_message)
 
 class AssumeValidTest(BitcoinTestFramework):
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.setup_clean_chain = True
         self.num_nodes = 3
 

test/functional/bip65-cltv-p2p.py

@@ -60,9 +60,7 @@ def create_transaction(node, coinbase, to_address, amount):
     return tx
 
 class BIP65Test(BitcoinTestFramework):
-
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 1
         self.extra_args = [['-promiscuousmempoolflags=1', '-whitelist=127.0.0.1']]
         self.setup_clean_chain = True

test/functional/bip68-112-113-p2p.py

@@ -92,9 +92,9 @@ def all_rlt_txs(txarray):
     return txs
 
 class BIP68_112_113Test(ComparisonTestFramework):
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 1
+        self.setup_clean_chain = True
         self.extra_args = [['-whitelist=127.0.0.1', '-blockversion=4']]
 
     def run_test(self):

test/functional/bip68-sequence.py

@@ -17,10 +17,8 @@
 NOT_FINAL_ERROR = "64: non-BIP68-final"
 
 class BIP68Test(BitcoinTestFramework):
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 2
-        self.setup_clean_chain = False
         self.extra_args = [[], ["-acceptnonstdtxn=0"]]
 
     def run_test(self):

test/functional/bip9-softforks.py

@@ -28,11 +28,10 @@
 from test_framework.script import CScript, OP_1NEGATE, OP_CHECKSEQUENCEVERIFY, OP_DROP
 
 class BIP9SoftForksTest(ComparisonTestFramework):
-
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 1
         self.extra_args = [['-whitelist=127.0.0.1']]
+        self.setup_clean_chain = True
 
     def run_test(self):
         self.test = TestManager(self, self.options.tmpdir)

test/functional/bipdersig-p2p.py

@@ -48,9 +48,7 @@ def create_transaction(node, coinbase, to_address, amount):
     return tx
 
 class BIP66Test(BitcoinTestFramework):
-
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 1
         self.extra_args = [['-promiscuousmempoolflags=1', '-whitelist=127.0.0.1']]
         self.setup_clean_chain = True

test/functional/blockchain.py

@@ -30,12 +30,8 @@
     assert_is_hash_string,
 )
 
-
 class BlockchainTest(BitcoinTestFramework):
-
-    def __init__(self):
-        super().__init__()
-        self.setup_clean_chain = False
+    def set_test_params(self):
         self.num_nodes = 1
         self.extra_args = [['-stopatheight=207']]
 

test/functional/bumpfee.py

@@ -30,8 +30,7 @@
 
 
 class BumpFeeTest(BitcoinTestFramework):
-    def __init__(self):
-        super().__init__()
+    def set_test_params(self):
         self.num_nodes = 2
         self.setup_clean_chain = True
         self.extra_args = [["-prematurewitness", "-walletprematurewitness", "-walletrbf={}".format(i)]