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

de8905adf2 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 de8905adf2. Great stuff gzhao408 . Thanks for this!

Tree-SHA512: 91572d43e203a1864765b93a9472667994115ec38b271f2b2f9fcd0f0112b393fc24ba7d2371d5a34b0a6a4522f6b934fc5164363819aa7ed8d6c6c9a60cc101

test/functional/test_runner.py

@@ -24,6 +24,7 @@ import sys
 import tempfile
 import re
 import logging
+import unittest
 
 # Formatting. Default colors to empty strings.
 BOLD, GREEN, RED, GREY = ("", ""), ("", ""), ("", ""), ("", "")
@@ -65,6 +66,10 @@ if os.name != 'nt' or sys.getwindowsversion() >= (10, 0, 14393):
 TEST_EXIT_PASSED = 0
 TEST_EXIT_SKIPPED = 77
 
+TEST_FRAMEWORK_MODULES = [
+    "script",
+]
+
 EXTENDED_SCRIPTS = [
     # These tests are not run by default.
     # Longest test should go first, to favor running tests in parallel
@@ -237,7 +242,6 @@ BASE_SCRIPTS = [
     'rpc_help.py',
     'feature_help.py',
     'feature_shutdown.py',
-    'framework_test_script.py',
     # Don't append tests at the end to avoid merge conflicts
     # Put them in a random line within the section that fits their approximate run-time
 ]
@@ -400,6 +404,16 @@ def run_tests(*, test_list, src_dir, build_dir, tmpdir, jobs=1, enable_coverage=
     if os.path.isdir(cache_dir):
         print("%sWARNING!%s There is a cache directory here: %s. If tests fail unexpectedly, try deleting the cache directory." % (BOLD[1], BOLD[0], cache_dir))
 
+    # Test Framework Tests
+    print("Running Unit Tests for Test Framework Modules")
+    test_framework_tests = unittest.TestSuite()
+    for module in TEST_FRAMEWORK_MODULES:
+        test_framework_tests.addTest(unittest.TestLoader().loadTestsFromName("test_framework.{}".format(module)))
+    result = unittest.TextTestRunner(verbosity=1, failfast=True).run(test_framework_tests)
+    if not result.wasSuccessful():
+        logging.debug("Early exiting after failure in TestFramework unit tests")
+        sys.exit(False)
+
     tests_dir = src_dir + '/test/functional/'
 
     flags = ['--cachedir={}'.format(cache_dir)] + args
@@ -623,7 +637,7 @@ class TestResult():
 def check_script_prefixes():
     """Check that test scripts start with one of the allowed name prefixes."""
 
-    good_prefixes_re = re.compile("^(example|feature|interface|mempool|mining|p2p|rpc|wallet|tool|framework_test)_")
+    good_prefixes_re = re.compile("^(example|feature|interface|mempool|mining|p2p|rpc|wallet|tool)_")
     bad_script_names = [script for script in ALL_SCRIPTS if good_prefixes_re.match(script) is None]
 
     if bad_script_names: