test/run-tests: Print a note if it looks like unittest.main() missing.

This work was funded through GitHub Sponsors.

Signed-off-by: Angus Gratton <angus@redyak.com.au>

Author: projectgus

tests/run-tests.py

@@ -1004,6 +1004,16 @@ def run_one_test(test_file):
 
         test_count.increment()
 
+        # Print a note if this looks like it might have been a misfired unittest
+        if not uses_unittest and not test_passed:
+            with open(test_file, "r") as f:
+                if any(re.match("^import.+unittest", l) for l in f.readlines()):
+                    print(
+                        "NOTE: {} may be a unittest that doesn't run unittest.main()".format(
+                            test_file
+                        )
+                    )
+
     if pyb:
         num_threads = 1