kunit: tool: make parser preserve whitespace when printing test log

Currently, kunit_parser.py is stripping all leading whitespace to make
parsing easier. But this means we can't accurately show kernel output
for failing tests or when the kernel crashes.

Embarassingly, this affects even KUnit's own output, e.g.
[13:40:46] Expected 2 + 1 == 2, but
[13:40:46] 2 + 1 == 3 (0x3)
[13:40:46] not ok 1 example_simple_test
[13:40:46] [FAILED] example_simple_test

After this change, here's what the output in context would look like
[13:40:46] =================== example (4 subtests) ===================
[13:40:46] # example_simple_test: initializing
[13:40:46] # example_simple_test: EXPECTATION FAILED at lib/kunit/kunit-example-test.c:29
[13:40:46] Expected 2 + 1 == 2, but
[13:40:46]     2 + 1 == 3 (0x3)
[13:40:46] [FAILED] example_simple_test
[13:40:46] [SKIPPED] example_skip_test
[13:40:46] [SKIPPED] example_mark_skipped_test
[13:40:46] [PASSED] example_all_expect_macros_test
[13:40:46]     # example: initializing suite
[13:40:46] # example: pass:1 fail:1 skip:2 total:4
[13:40:46] # Totals: pass:1 fail:1 skip:2 total:4
[13:40:46] ===================== [FAILED] example =====================

This example shows one minor cosmetic defect this approach has.
The test counts lines prevent us from dedenting the suite-level output.
But at the same time, any form of non-KUnit output would do the same
unless it happened to be indented as well.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

tools/testing/kunit/kunit.py

@@ -202,7 +202,7 @@ def parse_tests(request: KunitParseRequest, metadata: kunit_json.Metadata, input
 		if request.raw_output == 'all':
 			pass
 		elif request.raw_output == 'kunit':
-			output = kunit_parser.extract_tap_lines(output, lstrip=False)
+			output = kunit_parser.extract_tap_lines(output)
 		for line in output:
 			print(line.rstrip())
 		parse_time = time.time() - parse_start

tools/testing/kunit/kunit_parser.py

@@ -13,6 +13,7 @@ from __future__ import annotations
 from dataclasses import dataclass
 import re
 import sys
+import textwrap
 
 from enum import Enum, auto
 from typing import Iterable, Iterator, List, Optional, Tuple
@@ -208,12 +209,12 @@ class LineStream:
 
 # Parsing helper methods:
 
-KTAP_START = re.compile(r'KTAP version ([0-9]+)$')
-TAP_START = re.compile(r'TAP version ([0-9]+)$')
-KTAP_END = re.compile('(List of all partitions:|'
+KTAP_START = re.compile(r'\s*KTAP version ([0-9]+)$')
+TAP_START = re.compile(r'\s*TAP version ([0-9]+)$')
+KTAP_END = re.compile(r'\s*(List of all partitions:|'
 	'Kernel panic - not syncing: VFS:|reboot: System halted)')
 
-def extract_tap_lines(kernel_output: Iterable[str], lstrip=True) -> LineStream:
+def extract_tap_lines(kernel_output: Iterable[str]) -> LineStream:
 	"""Extracts KTAP lines from the kernel output."""
 	def isolate_ktap_output(kernel_output: Iterable[str]) \
 			-> Iterator[Tuple[int, str]]:
@@ -239,11 +240,8 @@ def extract_tap_lines(kernel_output: Iterable[str], lstrip=True) -> LineStream:
 				# stop extracting KTAP lines
 				break
 			elif started:
-				# remove the prefix and optionally any leading
-				# whitespace. Our parsing logic relies on this.
+				# remove the prefix, if any.
 				line = line[prefix_len:]
-				if lstrip:
-					line = line.lstrip()
 				yield line_num, line
 	return LineStream(lines=isolate_ktap_output(kernel_output))
 
@@ -298,7 +296,7 @@ def parse_ktap_header(lines: LineStream, test: Test) -> bool:
 	lines.pop()
 	return True
 
-TEST_HEADER = re.compile(r'^# Subtest: (.*)$')
+TEST_HEADER = re.compile(r'^\s*# Subtest: (.*)$')
 
 def parse_test_header(lines: LineStream, test: Test) -> bool:
 	"""
@@ -322,7 +320,7 @@ def parse_test_header(lines: LineStream, test: Test) -> bool:
 	lines.pop()
 	return True
 
-TEST_PLAN = re.compile(r'1\.\.([0-9]+)')
+TEST_PLAN = re.compile(r'^\s*1\.\.([0-9]+)')
 
 def parse_test_plan(lines: LineStream, test: Test) -> bool:
 	"""
@@ -350,9 +348,9 @@ def parse_test_plan(lines: LineStream, test: Test) -> bool:
 	lines.pop()
 	return True
 
-TEST_RESULT = re.compile(r'^(ok|not ok) ([0-9]+) (- )?([^#]*)( # .*)?$')
+TEST_RESULT = re.compile(r'^\s*(ok|not ok) ([0-9]+) (- )?([^#]*)( # .*)?$')
 
-TEST_RESULT_SKIP = re.compile(r'^(ok|not ok) ([0-9]+) (- )?(.*) # SKIP(.*)$')
+TEST_RESULT_SKIP = re.compile(r'^\s*(ok|not ok) ([0-9]+) (- )?(.*) # SKIP(.*)$')
 
 def peek_test_name_match(lines: LineStream, test: Test) -> bool:
 	"""
@@ -511,8 +509,9 @@ def print_test_header(test: Test) -> None:
 
 def print_log(log: Iterable[str]) -> None:
 	"""Prints all strings in saved log for test in yellow."""
-	for m in log:
-		stdout.print_with_timestamp(stdout.yellow(m))
+	formatted = textwrap.dedent('\n'.join(log))
+	for line in formatted.splitlines():
+		stdout.print_with_timestamp(stdout.yellow(line))
 
 def format_test_result(test: Test) -> str:
 	"""

tools/testing/kunit/kunit_tool_test.py

@@ -336,12 +336,14 @@ class KUnitParserTest(unittest.TestCase):
 		KTAP version 1
 		1..1
 		  Test output.
+		    Indented more.
 		not ok 1 test1
 		"""
 		result = kunit_parser.parse_run_tests(output.splitlines())
 		self.assertEqual(kunit_parser.TestStatus.FAILURE, result.status)
 
 		self.print_mock.assert_any_call(StrContains('Test output.'))
+		self.print_mock.assert_any_call(StrContains('  Indented more.'))
 		self.noPrintCallContains('not ok 1 test1')
 
 def line_stream_from_strs(strs: Iterable[str]) -> kunit_parser.LineStream: