Merge #18576: test: use unittest for test_framework unit testing

de8905adf204c42bba810802f82b98f7b3dd26dc test: use unittest and test_runner for test framework unit testing (Gloria Zhao)

Pull request description:

  Proposal for unit testing on test_framework functions:
  1. Use the python `unittest` library. Don't use test_framework to test itself.
  2. Put the tests inside the same file as the functions they are testing.
  3. Call the tests from `test_runner.py`. To include more Test Framework tests, add the filename to the list `TEST_FRAMEWORK_MODULES`. Don't add new files or change the list of accepted script prefixes.

  Makes these changes for `bn2vch` (followup to [this comment](https://github.com/bitcoin/bitcoin/pull/18378#pullrequestreview-377271264)).

ACKs for top commit:
  jnewbery:
    Tested ACK de8905adf204c42bba810802f82b98f7b3dd26dc. Great stuff gzhao408 . Thanks for this!

Tree-SHA512: 91572d43e203a1864765b93a9472667994115ec38b271f2b2f9fcd0f0112b393fc24ba7d2371d5a34b0a6a4522f6b934fc5164363819aa7ed8d6c6c9a60cc101

1 files changed, 23 insertions, 0 deletions

diff --git a/test/functional/test_framework/script.py b/test/functional/test_framework/script.py
index e475ed8596..9102266456 100644
--- a/test/functional/test_framework/script.py
+++ b/test/functional/test_framework/script.py
@@ -8,6 +8,7 @@ This file is modified from python-bitcoinlib.
 """
 import hashlib
 import struct
+import unittest
 
 from .messages import (
     CTransaction,
@@ -708,3 +709,25 @@ def SegwitV0SignatureHash(script, txTo, inIdx, hashtype, amount):
     ss += struct.pack("<I", hashtype)
 
     return hash256(ss)
+
+class TestFrameworkScript(unittest.TestCase):
+    def test_bn2vch(self):
+        self.assertEqual(bn2vch(0), bytes([]))
+        self.assertEqual(bn2vch(1), bytes([0x01]))
+        self.assertEqual(bn2vch(-1), bytes([0x81]))
+        self.assertEqual(bn2vch(0x7F), bytes([0x7F]))
+        self.assertEqual(bn2vch(-0x7F), bytes([0xFF]))
+        self.assertEqual(bn2vch(0x80), bytes([0x80, 0x00]))
+        self.assertEqual(bn2vch(-0x80), bytes([0x80, 0x80]))
+        self.assertEqual(bn2vch(0xFF), bytes([0xFF, 0x00]))
+        self.assertEqual(bn2vch(-0xFF), bytes([0xFF, 0x80]))
+        self.assertEqual(bn2vch(0x100), bytes([0x00, 0x01]))
+        self.assertEqual(bn2vch(-0x100), bytes([0x00, 0x81]))
+        self.assertEqual(bn2vch(0x7FFF), bytes([0xFF, 0x7F]))
+        self.assertEqual(bn2vch(-0x8000), bytes([0x00, 0x80, 0x80]))
+        self.assertEqual(bn2vch(-0x7FFFFF), bytes([0xFF, 0xFF, 0xFF]))
+        self.assertEqual(bn2vch(0x80000000), bytes([0x00, 0x00, 0x00, 0x80, 0x00]))
+        self.assertEqual(bn2vch(-0x80000000), bytes([0x00, 0x00, 0x00, 0x80, 0x80]))
+        self.assertEqual(bn2vch(0xFFFFFFFF), bytes([0xFF, 0xFF, 0xFF, 0xFF, 0x00]))
+        self.assertEqual(bn2vch(123456789), bytes([0x15, 0xCD, 0x5B, 0x07]))
+        self.assertEqual(bn2vch(-54321), bytes([0x31, 0xD4, 0x80]))