tests/run-tests.py: Add an argument for showing which tests would run.

This is convenient when trying to figure out the correct values
for --include/--exclude/--test-dirs/... arguments.

Signed-off-by: stijn <stijn@ignitron.net>

Author: stinos

tests/run-tests.py

@@ -887,6 +887,10 @@ def run_one_test(test_file):
             print("skip ", test_file)
             test_results.append((test_file, "skip", ""))
             return
+        elif args.dry_run:
+            print("found", test_file)
+            test_results.append((test_file, "found", ""))
+            return
 
         # Run the test on the MicroPython target.
         output_mupy = run_micropython(pyb, args, test_file, test_file_abspath)
@@ -1109,6 +1113,11 @@ def main():
         dest="filters",
         help="include test by regex on path/name.py",
     )
+    cmd_parser.add_argument(
+        "--dry-run",
+        action="store_true",
+        help="Show tests which would run (though might still be skipped at runtime)",
+    )
     cmd_parser.add_argument(
         "--emit", default="bytecode", help="MicroPython emitter to use (bytecode or native)"
     )

tests/test_utils.py

@@ -313,15 +313,21 @@ def create_test_report(args, test_results, testcase_count=None):
         r for r in test_results if r[1] == "skip" and r[2] == "too large"
     )
     failed_tests = list(r for r in test_results if r[1] == "fail")
+    dry_run = getattr(args, "dry_run", False)
+    if dry_run:
+        found_tests = list(r for r in test_results if r[1] == "found")
 
     num_tests_performed = len(passed_tests) + len(failed_tests)
 
-    testcase_count_info = ""
-    if testcase_count is not None:
-        testcase_count_info = " ({} individual testcases)".format(testcase_count)
-    print("{} tests performed{}".format(num_tests_performed, testcase_count_info))
+    if dry_run:
+        print("{} tests found".format(len(found_tests)))
+    else:
+        testcase_count_info = ""
+        if testcase_count is not None:
+            testcase_count_info = " ({} individual testcases)".format(testcase_count)
+        print("{} tests performed{}".format(num_tests_performed, testcase_count_info))
 
-    print("{} tests passed".format(len(passed_tests)))
+        print("{} tests passed".format(len(passed_tests)))
 
     if len(skipped_tests) > 0:
         print(