Merge bitcoin/bitcoin#29500: test: create assert_not_equal util

7bb83f6718 test: create assert_not_equal util and add to where imports are needed (kevkevin)

Pull request description:

  In the functional tests there are lots of cases where we assert != which we now swap with assert_not_equal to be more readable

  This is motivated/uses logic from this PR which was closed https://github.com/bitcoin/bitcoin/pull/28528
  This partially helps https://github.com/bitcoin/bitcoin/issues/23119

  I've broken it up to just `assert_not_equal` to keep the PR smaller as suggested in https://github.com/bitcoin/bitcoin/pull/28528#issuecomment-1959945805

  I can create follow up PR's if this is wanted

ACKs for top commit:
  hodlinator:
    re-ACK 7bb83f6718
  ryanofsky:
    Code review ACK 7bb83f6718. Only change since last review is fixing error message formatting and passing it as a keyword argument
  janb84:
    Re-ACK [7bb83f6](7bb83f6718)

Tree-SHA512: de09f41a690033a5b61e6f861d3bd69a32b889d6655a28fbc0d5cfac9f7ec9c642432967d33913970882b4cfdd47bdd377d0ddc44e25976cbaa49f7f9d8f7b10

test/functional/test_framework/crypto/secp256k1.py

@@ -17,6 +17,7 @@ Exports:
 
 import unittest
 from hashlib import sha256
+from test_framework.util import assert_not_equal
 
 class FE:
     """Objects of this class represent elements of the field GF(2**256 - 2**32 - 977).
@@ -40,7 +41,7 @@ class FE:
             num = (num * b._den) % FE.SIZE
         else:
             den = (den * b) % FE.SIZE
-        assert den != 0
+        assert_not_equal(den, 0)
         if num == 0:
             den = 1
         self._num = num

test/functional/test_framework/key.py

@@ -14,7 +14,7 @@ import random
 import unittest
 
 from test_framework.crypto import secp256k1
-from test_framework.util import random_bitflip
+from test_framework.util import assert_not_equal, random_bitflip
 
 # Point with no known discrete log.
 H_POINT = "50929b74c1a04954b78b4b6035e97a5e078a5a0f28ec96d547bfee9ace803ac0"
@@ -283,7 +283,7 @@ def sign_schnorr(key, msg, aux=None, flip_p=False, flip_r=False):
         sec = ORDER - sec
     t = (sec ^ int.from_bytes(TaggedHash("BIP0340/aux", aux), 'big')).to_bytes(32, 'big')
     kp = int.from_bytes(TaggedHash("BIP0340/nonce", t + P.to_bytes_xonly() + msg), 'big') % ORDER
-    assert kp != 0
+    assert_not_equal(kp, 0)
     R = kp * secp256k1.G
     k = kp if R.y.is_even() != flip_r else ORDER - kp
     e = int.from_bytes(TaggedHash("BIP0340/challenge", R.to_bytes_xonly() + P.to_bytes_xonly() + msg), 'big') % ORDER

test/functional/test_framework/p2p.py

@@ -77,6 +77,7 @@ from test_framework.messages import (
     sha256,
 )
 from test_framework.util import (
+    assert_not_equal,
     MAX_NODES,
     p2p_port,
     wait_until_helper_internal,
@@ -897,7 +898,7 @@ class P2PDataStore(P2PInterface):
             if success:
                 self.wait_until(lambda: node.getbestblockhash() == blocks[-1].hash, timeout=timeout)
             else:
-                assert node.getbestblockhash() != blocks[-1].hash
+                assert_not_equal(node.getbestblockhash(), blocks[-1].hash)
 
     def send_txs_and_test(self, txs, node, *, success=True, expect_disconnect=False, reject_reason=None):
         """Send txs to test node and test whether they're accepted to the mempool.

test/functional/test_framework/test_node.py

@@ -33,6 +33,7 @@ from .p2p import P2P_SERVICES, P2P_SUBVERSION
 from .util import (
     MAX_NODES,
     assert_equal,
+    assert_not_equal,
     append_config,
     delete_cookie_file,
     get_auth_cookie,
@@ -668,7 +669,7 @@ class TestNode():
                 self.start(extra_args, stdout=log_stdout, stderr=log_stderr, *args, **kwargs)
                 ret = self.process.wait(timeout=self.rpc_timeout)
                 self.log.debug(self._node_msg(f'bitcoind exited with status {ret} during initialization'))
-                assert ret != 0  # Exit code must indicate failure
+                assert_not_equal(ret, 0) # Exit code must indicate failure
                 self.running = False
                 self.process = None
                 # Check stderr for expected message

test/functional/test_framework/util.py

@@ -76,6 +76,10 @@ def assert_equal(thing1, thing2, *args):
     if thing1 != thing2 or any(thing1 != arg for arg in args):
         raise AssertionError("not(%s)" % " == ".join(str(arg) for arg in (thing1, thing2) + args))
 
+def assert_not_equal(thing1, thing2, *, error_message=""):
+    if thing1 == thing2:
+        raise AssertionError(f"Both values are {thing1}{f', {error_message}' if error_message else ''}")
+
 
 def assert_greater_than(thing1, thing2):
     if thing1 <= thing2: