[lldb][test] Switch LLDB API tests from vendored unittest2 to unittest (#79945)

This removes the dependency LLDB API tests have on
lldb/third_party/Python/module/unittest2, and instead uses the standard
one provided by Python.

This does not actually remove the vendored dep yet, nor update the docs.
I'll do both those once this sticks.

Non-trivial changes to call out:
- expected failures (i.e. "bugnumber") don't have a reason anymore, so
those params were removed
- `assertItemsEqual` is now called `assertCountEqual`
- When a test is marked xfail, our copy of unittest2 considers failures
during teardown to be OK, but modern unittest does not. See
TestThreadLocal.py. (Very likely could be a real bug/leak).
- Our copy of unittest2 was patched to print all test results, even ones
that don't happen, e.g. `(5 passes, 0 failures, 1 errors, 0 skipped,
...)`, but standard unittest prints a terser message that omits test
result types that didn't happen, e.g. `OK (skipped=1)`. Our lit
integration parses this stderr and needs to be updated w/ that
expectation.

I tested this w/ `ninja check-lldb-api` on Linux. There's a good chance
non-Linux tests have similar quirks, but I'm not able to uncover those.

1 files changed, 9 insertions, 19 deletions

diff --git a/lldb/packages/Python/lldbsuite/test/lldbtest.py b/lldb/packages/Python/lldbsuite/test/lldbtest.py
index d944b09..018f2a0 100644
--- a/lldb/packages/Python/lldbsuite/test/lldbtest.py
+++ b/lldb/packages/Python/lldbsuite/test/lldbtest.py
@@ -44,7 +44,7 @@ import time
 import traceback
 
 # Third-party modules
-import unittest2
+import unittest
 
 # LLDB modules
 import lldb
@@ -517,7 +517,7 @@ def builder_module():
     return lldbplatformutil.builder_module()
 
 
-class Base(unittest2.TestCase):
+class Base(unittest.TestCase):
     """
     Abstract base for performing lldb (see TestBase) or other generic tests (see
     BenchBase for one example).  lldbtest.Base works with the test driver to
@@ -1090,17 +1090,14 @@ class Base(unittest2.TestCase):
             # Once by the Python unittest framework, and a second time by us.
             print("FAIL", file=sbuf)
 
-    def markExpectedFailure(self, err, bugnumber):
+    def markExpectedFailure(self, err):
         """Callback invoked when an expected failure/error occurred."""
         self.__expected__ = True
         with recording(self, False) as sbuf:
             # False because there's no need to write "expected failure" to the
             # stderr twice.
             # Once by the Python unittest framework, and a second time by us.
-            if bugnumber is None:
-                print("expected failure", file=sbuf)
-            else:
-                print("expected failure (problem id:" + str(bugnumber) + ")", file=sbuf)
+            print("expected failure", file=sbuf)
 
     def markSkippedTest(self):
         """Callback invoked when a test is skipped."""
@@ -1111,19 +1108,14 @@ class Base(unittest2.TestCase):
             # Once by the Python unittest framework, and a second time by us.
             print("skipped test", file=sbuf)
 
-    def markUnexpectedSuccess(self, bugnumber):
+    def markUnexpectedSuccess(self):
         """Callback invoked when an unexpected success occurred."""
         self.__unexpected__ = True
         with recording(self, False) as sbuf:
             # False because there's no need to write "unexpected success" to the
             # stderr twice.
             # Once by the Python unittest framework, and a second time by us.
-            if bugnumber is None:
-                print("unexpected success", file=sbuf)
-            else:
-                print(
-                    "unexpected success (problem id:" + str(bugnumber) + ")", file=sbuf
-                )
+            print("unexpected success", file=sbuf)
 
     def getRerunArgs(self):
         return " -f %s.%s" % (self.__class__.__name__, self._testMethodName)
@@ -1704,13 +1696,11 @@ class LLDBTestCaseFactory(type):
 
                     xfail_reason = xfail_for_debug_info_cat_fn(cat)
                     if xfail_reason:
-                        test_method = unittest2.expectedFailure(xfail_reason)(
-                            test_method
-                        )
+                        test_method = unittest.expectedFailure(test_method)
 
                     skip_reason = skip_for_debug_info_cat_fn(cat)
                     if skip_reason:
-                        test_method = unittest2.skip(skip_reason)(test_method)
+                        test_method = unittest.skip(skip_reason)(test_method)
 
                     newattrs[method_name] = test_method
 
@@ -2226,7 +2216,7 @@ class TestBase(Base, metaclass=LLDBTestCaseFactory):
         match_strings = lldb.SBStringList()
         interp.HandleCompletion(command, len(command), 0, -1, match_strings)
         # match_strings is a 1-indexed list, so we have to slice...
-        self.assertItemsEqual(
+        self.assertCountEqual(
             completions, list(match_strings)[1:], "List of returned completion is wrong"
         )