kunit: tool: Only print the summary

Allow only printing the summary at the end of a test run, rather than all
individual test results. This summary will list a few failing tests if
there are any.

To use:

./tools/testing/kunit/kunit.py run --summary

Link: https://lore.kernel.org/r/20241113222406.1590372-1-rmoar@google.com
Signed-off-by: Rae Moar <rmoar@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/kunit/kunit.py

@@ -23,7 +23,7 @@
 import kunit_json
 import kunit_kernel
 import kunit_parser
-from kunit_printer import stdout
+from kunit_printer import stdout, null_printer
 
 class KunitStatus(Enum):
 	SUCCESS = auto()
@@ -49,6 +49,7 @@ class KunitBuildRequest(KunitConfigRequest):
 class KunitParseRequest:
 	raw_output: Optional[str]
 	json: Optional[str]
+	summary: bool
 
 @dataclass
 class KunitExecRequest(KunitParseRequest):
@@ -235,11 +236,16 @@ def parse_tests(request: KunitParseRequest, metadata: kunit_json.Metadata, input
 		parse_time = time.time() - parse_start
 		return KunitResult(KunitStatus.SUCCESS, parse_time), fake_test
 
+	default_printer = stdout
+	if request.summary:
+		default_printer = null_printer
 
 	# Actually parse the test results.
-	test = kunit_parser.parse_run_tests(input_data)
+	test = kunit_parser.parse_run_tests(input_data, default_printer)
 	parse_time = time.time() - parse_start
 
+	kunit_parser.print_summary_line(test, stdout)
+
 	if request.json:
 		json_str = kunit_json.get_json_result(
 					test=test,
@@ -413,6 +419,10 @@ def add_parse_opts(parser: argparse.ArgumentParser) -> None:
 			    help='Prints parsed test results as JSON to stdout or a file if '
 			    'a filename is specified. Does nothing if --raw_output is set.',
 			    type=str, const='stdout', default=None, metavar='FILE')
+	parser.add_argument('--summary',
+			    help='Prints only the summary line for parsed test results.'
+				'Does nothing if --raw_output is set.',
+			    action='store_true')
 
 
 def tree_from_args(cli_args: argparse.Namespace) -> kunit_kernel.LinuxSourceTree:
@@ -448,6 +458,7 @@ def run_handler(cli_args: argparse.Namespace) -> None:
 					jobs=cli_args.jobs,
 					raw_output=cli_args.raw_output,
 					json=cli_args.json,
+					summary=cli_args.summary,
 					timeout=cli_args.timeout,
 					filter_glob=cli_args.filter_glob,
 					filter=cli_args.filter,
@@ -495,6 +506,7 @@ def exec_handler(cli_args: argparse.Namespace) -> None:
 	exec_request = KunitExecRequest(raw_output=cli_args.raw_output,
 					build_dir=cli_args.build_dir,
 					json=cli_args.json,
+					summary=cli_args.summary,
 					timeout=cli_args.timeout,
 					filter_glob=cli_args.filter_glob,
 					filter=cli_args.filter,
@@ -520,7 +532,7 @@ def parse_handler(cli_args: argparse.Namespace) -> None:
 	# We know nothing about how the result was created!
 	metadata = kunit_json.Metadata()
 	request = KunitParseRequest(raw_output=cli_args.raw_output,
-					json=cli_args.json)
+					json=cli_args.json, summary=cli_args.summary)
 	result, _ = parse_tests(request, metadata, kunit_output)
 	if result.status != KunitStatus.SUCCESS:
 		sys.exit(1)