- added flag to disable using branch coverage, to work around

  issues seen with SlipCover's branch coverage implementation
  on Python 3.12;

src/coverup/coverup.py

@@ -132,6 +132,10 @@ def default_model():
                     action=argparse.BooleanOptionalAction,
                     help='add (parent of) source directory to PYTHONPATH')
 
+    ap.add_argument('--branch-coverage', default=True,
+                    action=argparse.BooleanOptionalAction,
+                    help=argparse.SUPPRESS)
+
     def positive_int(value):
         ivalue = int(value)
         if ivalue < 0: raise argparse.ArgumentTypeError("must be a number >= 0")
@@ -216,6 +220,7 @@ def check_whole_suite() -> None:
         print("Checking test suite...  ", end='', flush=True)
         try:
             btf = BadTestsFinder(tests_dir=args.tests_dir, pytest_args=pytest_args,
+                                 branch_coverage=args.branch_coverage,
                                  trace=(print if args.debug else None))
             outcomes = btf.run_tests()
             failing_tests = list(p for p, o in outcomes.items() if o == 'failed')
@@ -240,6 +245,7 @@ def print_noeol(message):
 
             try:
                 btf = BadTestsFinder(tests_dir=args.tests_dir, pytest_args=args.pytest_args,
+                                     branch_coverage=args.branch_coverage,
                                      trace=(print if args.debug else None),
                                      progress=(print if args.debug else print_noeol))
 
@@ -561,6 +567,7 @@ def log_prompts(prompts: T.List[dict]):
 
         try:
             result = await measure_test_coverage(test=last_test, tests_dir=args.tests_dir, pytest_args=args.pytest_args,
+                                                 branch_coverage=args.branch_coverage,
                                                  log_write=lambda msg: log_write(seg, msg))
 
         except subprocess.TimeoutExpired:
@@ -578,7 +585,7 @@ def log_prompts(prompts: T.List[dict]):
 
         new_lines = set(result[seg.filename]['executed_lines']) if seg.filename in result else set()
         new_branches = set(tuple(b) for b in result[seg.filename]['executed_branches']) \
-                       if seg.filename in result else set()
+                       if (seg.filename in result and 'executed_branches' in result[seg.filename]) else set()
         now_missing_lines = seg.missing_lines - new_lines
         now_missing_branches = seg.missing_branches - new_branches
 
@@ -691,6 +698,7 @@ def main():
                 coverage = measure_suite_coverage(tests_dir=args.tests_dir, source_dir=args.source_dir,
                                                   pytest_args=args.pytest_args,
                                                   isolate_tests=args.isolate_tests,
+                                                  branch_coverage=args.branch_coverage,
                                                   trace=(print if args.debug else None))
                 state = State(coverage)
 
@@ -777,6 +785,7 @@ async def sem_coro(coro):
             coverage = measure_suite_coverage(tests_dir=args.tests_dir, source_dir=args.source_dir,
                                               pytest_args=args.pytest_args,
                                               isolate_tests=args.isolate_tests,
+                                              branch_coverage=args.branch_coverage,
                                               trace=(print if args.debug else None))
 
         except subprocess.CalledProcessError as e:

src/coverup/testrunner.py

@@ -11,7 +11,7 @@
 from .utils import subprocess_run
 
 
-async def measure_test_coverage(*, test: str, tests_dir: Path, pytest_args='', log_write=None):
+async def measure_test_coverage(*, test: str, tests_dir: Path, pytest_args='', log_write=None, branch_coverage=True):
     """Runs a given test and returns the coverage obtained."""
     with tempfile.NamedTemporaryFile(prefix="tmp_test_", suffix='.py', dir=str(tests_dir), mode="w") as t:
         t.write(test)
@@ -20,7 +20,8 @@ async def measure_test_coverage(*, test: str, tests_dir: Path, pytest_args='', l
         with tempfile.NamedTemporaryFile(suffix='.json', delete=False) as j:
             try:
                 # -qq to cut down on tokens
-                p = await subprocess_run([sys.executable, '-m', 'slipcover', '--branch', '--json', '--out', j.name,
+                p = await subprocess_run([sys.executable, '-m', 'slipcover'] + (['--branch'] if branch_coverage else []) + \
+                                         ['--json', '--out', j.name,
                                           '-m', 'pytest'] + pytest_args.split() + ['-qq', '-x', '--disable-warnings', t.name],
                                          check=True, timeout=60)
                 if log_write:
@@ -38,14 +39,15 @@ async def measure_test_coverage(*, test: str, tests_dir: Path, pytest_args='', l
     return cov["files"]
 
 
-def measure_suite_coverage(*, tests_dir: Path, source_dir: Path, pytest_args='', trace=None, isolate_tests=False):
+def measure_suite_coverage(*, tests_dir: Path, source_dir: Path, pytest_args='', trace=None, isolate_tests=False, branch_coverage=True):
     """Runs an entire test suite and returns the coverage obtained."""
 
     with tempfile.NamedTemporaryFile(suffix='.json', delete=False) as j:
         try:
             command = [sys.executable,
-                       '-m', 'slipcover', '--source', source_dir, '--branch', '--json', '--out', j.name] + \
-                            (['--isolate-tests'] if isolate_tests else []) +\
+                       '-m', 'slipcover', '--source', source_dir] + (['--branch'] if branch_coverage else []) + \
+                            ['--json', '--out', j.name] + \
+                            (['--isolate-tests'] if isolate_tests else []) + \
                       ['-m', 'pytest'] + pytest_args.split() + ['-qq', '--disable-warnings', '-x', tests_dir]
 
             if trace: trace(command)
@@ -75,7 +77,7 @@ class BadTestFinderError(Exception):
 
 class BadTestsFinder(DeltaDebugger):
     """Finds tests that cause other tests to fail."""
-    def __init__(self, *, tests_dir: Path, pytest_args: str = '', trace = None, progress = None):
+    def __init__(self, *, tests_dir: Path, pytest_args: str = '', trace = None, progress = None, branch_coverage=True):
         super(BadTestsFinder, self).__init__(trace=trace)
         self.tests_dir = tests_dir
 
@@ -90,6 +92,7 @@ def find_tests(p):
 
         self.all_tests = set(find_tests(self.tests_dir))
         self.pytest_args = pytest_args.split()
+        self.branch_coverage = branch_coverage
         self.progress = progress
 
 
@@ -127,7 +130,8 @@ def to_tmpdir(p: Path):
                     command = [sys.executable,
                                # include SlipCover in case a test is failing because of it
                                # (in measure_suite_coverage)
-                               '-m', 'slipcover', '--branch', '--out', '/dev/null',
+                               '-m', 'slipcover'] + (['--branch'] if self.branch_coverage else []) + \
+                                    ['--out', '/dev/null',
                                "-m", "pytest"] + self.pytest_args + \
                               ['-qq', '--disable-warnings',
                                '-p', 'coverup.pytest_plugin', '--coverup-outcomes', str(outcomes_f.name)] \