blob: fbc094f0567e660c098c0c10acb2b8281cf276f8 [file] [log] [blame]
# SPDX-License-Identifier: GPL-2.0
# Parses KTAP test results from a kernel dmesg log and incrementally prints
# results with reader-friendly format. Stores and returns test results in a
# Test object.
# Copyright (C) 2019, Google LLC.
# Author: Felix Guo <>
# Author: Brendan Higgins <>
# Author: Rae Moar <>
from __future__ import annotations
from dataclasses import dataclass
import re
import textwrap
from enum import Enum, auto
from typing import Iterable, Iterator, List, Optional, Tuple
from kunit_printer import stdout
class Test:
A class to represent a test parsed from KTAP results. All KTAP
results within a test log are stored in a main Test object as
status : TestStatus - status of the test
name : str - name of the test
expected_count : int - expected number of subtests (0 if single
test case and None if unknown expected number of subtests)
subtests : List[Test] - list of subtests
log : List[str] - log of KTAP lines that correspond to the test
counts : TestCounts - counts of the test statuses and errors of
subtests or of the test itself if the test is a single
test case.
def __init__(self) -> None:
"""Creates Test object with default attributes."""
self.status = TestStatus.TEST_CRASHED = ''
self.expected_count = 0 # type: Optional[int]
self.subtests = [] # type: List[Test]
self.log = [] # type: List[str]
self.counts = TestCounts()
def __str__(self) -> str:
"""Returns string representation of a Test class object."""
return (f'Test({self.status}, {}, {self.expected_count}, '
f'{self.subtests}, {self.log}, {self.counts})')
def __repr__(self) -> str:
"""Returns string representation of a Test class object."""
return str(self)
def add_error(self, error_message: str) -> None:
"""Records an error that occurred while parsing this test."""
self.counts.errors += 1
stdout.print_with_timestamp('[ERROR]') + f' Test: {}: {error_message}')
def ok_status(self) -> bool:
"""Returns true if the status was ok, i.e. passed or skipped."""
return self.status in (TestStatus.SUCCESS, TestStatus.SKIPPED)
class TestStatus(Enum):
"""An enumeration class to represent the status of a test."""
SUCCESS = auto()
FAILURE = auto()
SKIPPED = auto()
NO_TESTS = auto()
class TestCounts:
Tracks the counts of statuses of all test cases and any errors within
a Test.
passed: int = 0
failed: int = 0
crashed: int = 0
skipped: int = 0
errors: int = 0
def __str__(self) -> str:
"""Returns the string representation of a TestCounts object."""
statuses = [('passed', self.passed), ('failed', self.failed),
('crashed', self.crashed), ('skipped', self.skipped),
('errors', self.errors)]
return f'Ran {} tests: ' + \
', '.join(f'{s}: {n}' for s, n in statuses if n > 0)
def total(self) -> int:
"""Returns the total number of test cases within a test
object, where a test case is a test with no subtests.
return (self.passed + self.failed + self.crashed +
def add_subtest_counts(self, counts: TestCounts) -> None:
Adds the counts of another TestCounts object to the current
TestCounts object. Used to add the counts of a subtest to the
parent test.
counts - a different TestCounts object whose counts
will be added to the counts of the TestCounts object
self.passed += counts.passed
self.failed += counts.failed
self.crashed += counts.crashed
self.skipped += counts.skipped
self.errors += counts.errors
def get_status(self) -> TestStatus:
"""Returns the aggregated status of a Test using test
if == 0:
return TestStatus.NO_TESTS
if self.crashed:
# Crashes should take priority.
return TestStatus.TEST_CRASHED
if self.failed:
return TestStatus.FAILURE
if self.passed:
# No failures or crashes, looks good!
return TestStatus.SUCCESS
# We have only skipped tests.
return TestStatus.SKIPPED
def add_status(self, status: TestStatus) -> None:
"""Increments the count for `status`."""
if status == TestStatus.SUCCESS:
self.passed += 1
elif status == TestStatus.FAILURE:
self.failed += 1
elif status == TestStatus.SKIPPED:
self.skipped += 1
elif status != TestStatus.NO_TESTS:
self.crashed += 1
class LineStream:
A class to represent the lines of kernel output.
Provides a lazy peek()/pop() interface over an iterator of
(line#, text).
_lines: Iterator[Tuple[int, str]]
_next: Tuple[int, str]
_need_next: bool
_done: bool
def __init__(self, lines: Iterator[Tuple[int, str]]):
"""Creates a new LineStream that wraps the given iterator."""
self._lines = lines
self._done = False
self._need_next = True
self._next = (0, '')
def _get_next(self) -> None:
"""Advances the LineSteam to the next line, if necessary."""
if not self._need_next:
self._next = next(self._lines)
except StopIteration:
self._done = True
self._need_next = False
def peek(self) -> str:
"""Returns the current line, without advancing the LineStream.
return self._next[1]
def pop(self) -> str:
"""Returns the current line and advances the LineStream to
the next line.
s = self.peek()
if self._done:
raise ValueError(f'LineStream: going past EOF, last line was {s}')
self._need_next = True
return s
def __bool__(self) -> bool:
"""Returns True if stream has more lines."""
return not self._done
# Only used by
def __iter__(self) -> Iterator[str]:
"""Empties all lines stored in LineStream object into
Iterator object and returns the Iterator object.
while bool(self):
yield self.pop()
def line_number(self) -> int:
"""Returns the line number of the current line."""
return self._next[0]
# Parsing helper methods:
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]) -> LineStream:
"""Extracts KTAP lines from the kernel output."""
def isolate_ktap_output(kernel_output: Iterable[str]) \
-> Iterator[Tuple[int, str]]:
line_num = 0
started = False
for line in kernel_output:
line_num += 1
line = line.rstrip() # remove trailing \n
if not started and
# start extracting KTAP lines and set prefix
# to number of characters before version line
prefix_len = len(
line.split('KTAP version')[0])
started = True
yield line_num, line[prefix_len:]
elif not started and
# start extracting KTAP lines and set prefix
# to number of characters before version line
prefix_len = len(line.split('TAP version')[0])
started = True
yield line_num, line[prefix_len:]
elif started and
# stop extracting KTAP lines
elif started:
# remove the prefix, if any.
line = line[prefix_len:]
yield line_num, line
return LineStream(lines=isolate_ktap_output(kernel_output))
TAP_VERSIONS = [13, 14]
def check_version(version_num: int, accepted_versions: List[int],
version_type: str, test: Test) -> None:
Adds error to test object if version number is too high or too
version_num - The inputted version number from the parsed KTAP or TAP
header line
accepted_version - List of accepted KTAP or TAP versions
version_type - 'KTAP' or 'TAP' depending on the type of
version line.
test - Test object for current test being parsed
if version_num < min(accepted_versions):
test.add_error(f'{version_type} version lower than expected!')
elif version_num > max(accepted_versions):
test.add_error(f'{version_type} version higer than expected!')
def parse_ktap_header(lines: LineStream, test: Test) -> bool:
Parses KTAP/TAP header line and checks version number.
Returns False if fails to parse KTAP/TAP header line.
Accepted formats:
- 'KTAP version [version number]'
- 'TAP version [version number]'
lines - LineStream of KTAP output to parse
test - Test object for current test being parsed
True if successfully parsed KTAP/TAP header line
ktap_match = KTAP_START.match(lines.peek())
tap_match = TAP_START.match(lines.peek())
if ktap_match:
version_num = int(
check_version(version_num, KTAP_VERSIONS, 'KTAP', test)
elif tap_match:
version_num = int(
check_version(version_num, TAP_VERSIONS, 'TAP', test)
return False
return True
TEST_HEADER = re.compile(r'^\s*# Subtest: (.*)$')
def parse_test_header(lines: LineStream, test: Test) -> bool:
Parses test header and stores test name in test object.
Returns False if fails to parse test header line.
Accepted format:
- '# Subtest: [test name]'
lines - LineStream of KTAP output to parse
test - Test object for current test being parsed
True if successfully parsed test header line
match = TEST_HEADER.match(lines.peek())
if not match:
return False =
return True
TEST_PLAN = re.compile(r'^\s*1\.\.([0-9]+)')
def parse_test_plan(lines: LineStream, test: Test) -> bool:
Parses test plan line and stores the expected number of subtests in
test object. Reports an error if expected count is 0.
Returns False and sets expected_count to None if there is no valid test
Accepted format:
- '1..[number of subtests]'
lines - LineStream of KTAP output to parse
test - Test object for current test being parsed
True if successfully parsed test plan line
match = TEST_PLAN.match(lines.peek())
if not match:
test.expected_count = None
return False
expected_count = int(
test.expected_count = expected_count
return True
TEST_RESULT = re.compile(r'^\s*(ok|not ok) ([0-9]+) (- )?([^#]*)( # .*)?$')
TEST_RESULT_SKIP = re.compile(r'^\s*(ok|not ok) ([0-9]+) (- )?(.*) # SKIP(.*)$')
def peek_test_name_match(lines: LineStream, test: Test) -> bool:
Matches current line with the format of a test result line and checks
if the name matches the name of the current test.
Returns False if fails to match format or name.
Accepted format:
- '[ok|not ok] [test number] [-] [test name] [optional skip
lines - LineStream of KTAP output to parse
test - Test object for current test being parsed
True if matched a test result line and the name matching the
expected test name
line = lines.peek()
match = TEST_RESULT.match(line)
if not match:
return False
name =
return name ==
def parse_test_result(lines: LineStream, test: Test,
expected_num: int) -> bool:
Parses test result line and stores the status and name in the test
object. Reports an error if the test number does not match expected
test number.
Returns False if fails to parse test result line.
Note that the SKIP directive is the only direction that causes a
change in status.
Accepted format:
- '[ok|not ok] [test number] [-] [test name] [optional skip
lines - LineStream of KTAP output to parse
test - Test object for current test being parsed
expected_num - expected test number for current test
True if successfully parsed a test result line.
line = lines.peek()
match = TEST_RESULT.match(line)
skip_match = TEST_RESULT_SKIP.match(line)
# Check if line matches test result line format
if not match:
return False
# Set name of test object
if skip_match: =
else: =
# Check test num
num = int(
if num != expected_num:
test.add_error(f'Expected test number {expected_num} but found {num}')
# Set status of test object
status =
if skip_match:
test.status = TestStatus.SKIPPED
elif status == 'ok':
test.status = TestStatus.SUCCESS
test.status = TestStatus.FAILURE
return True
def parse_diagnostic(lines: LineStream) -> List[str]:
Parse lines that do not match the format of a test result line or
test header line and returns them in list.
Line formats that are not parsed:
- '# Subtest: [test name]'
- '[ok|not ok] [test number] [-] [test name] [optional skip
- 'KTAP version [version number]'
lines - LineStream of KTAP output to parse
Log of diagnostic lines
log = [] # type: List[str]
non_diagnostic_lines = [TEST_RESULT, TEST_HEADER, KTAP_START]
while lines and not any(re.match(lines.peek())
for re in non_diagnostic_lines):
return log
# Printing helper methods:
DIVIDER = '=' * 60
def format_test_divider(message: str, len_message: int) -> str:
Returns string with message centered in fixed width divider.
'===================== message example ====================='
message - message to be centered in divider line
len_message - length of the message to be printed such that
any characters of the color codes are not counted
String containing message centered in fixed width divider
default_count = 3 # default number of dashes
len_1 = default_count
len_2 = default_count
difference = len(DIVIDER) - len_message - 2 # 2 spaces added
if difference > 0:
# calculate number of dashes for each side of the divider
len_1 = int(difference / 2)
len_2 = difference - len_1
return ('=' * len_1) + f' {message} ' + ('=' * len_2)
def print_test_header(test: Test) -> None:
Prints test header with test name and optionally the expected number
of subtests.
'=================== example (2 subtests) ==================='
test - Test object representing current test being printed
message =
if message != "":
# Add a leading space before the subtest counts only if a test name
# is provided using a "# Subtest" header line.
message += " "
if test.expected_count:
if test.expected_count == 1:
message += '(1 subtest)'
message += f'({test.expected_count} subtests)'
stdout.print_with_timestamp(format_test_divider(message, len(message)))
def print_log(log: Iterable[str]) -> None:
"""Prints all strings in saved log for test in yellow."""
formatted = textwrap.dedent('\n'.join(log))
for line in formatted.splitlines():
def format_test_result(test: Test) -> str:
Returns string with formatted test result with colored status and test
'[PASSED] example'
test - Test object representing current test being printed
String containing formatted test result
if test.status == TestStatus.SUCCESS:
return'[PASSED] ') +
if test.status == TestStatus.SKIPPED:
return stdout.yellow('[SKIPPED] ') +
if test.status == TestStatus.NO_TESTS:
return stdout.yellow('[NO TESTS RUN] ') +
if test.status == TestStatus.TEST_CRASHED:
return'[CRASHED] ') +
return'[FAILED] ') +
def print_test_result(test: Test) -> None:
Prints result line with status of test.
'[PASSED] example'
test - Test object representing current test being printed
def print_test_footer(test: Test) -> None:
Prints test footer with status of test.
'===================== [PASSED] example ====================='
test - Test object representing current test being printed
message = format_test_result(test)
len(message) - stdout.color_len()))
def _summarize_failed_tests(test: Test) -> str:
"""Tries to summarize all the failing subtests in `test`."""
def failed_names(test: Test, parent_name: str) -> List[str]:
# Note: we use 'main' internally for the top-level test.
if not parent_name or parent_name == 'main':
full_name =
full_name = parent_name + '.' +
if not test.subtests: # this is a leaf node
return [full_name]
# If all the children failed, just say this subtest failed.
# Don't summarize it down "the top-level test failed", though.
failed_subtests = [sub for sub in test.subtests if not sub.ok_status()]
if parent_name and len(failed_subtests) == len(test.subtests):
return [full_name]
all_failures = [] # type: List[str]
for t in failed_subtests:
all_failures.extend(failed_names(t, full_name))
return all_failures
failures = failed_names(test, '')
# If there are too many failures, printing them out will just be noisy.
if len(failures) > 10: # this is an arbitrary limit
return ''
return 'Failures: ' + ', '.join(failures)
def print_summary_line(test: Test) -> None:
Prints summary line of test object. Color of line is dependent on
status of test. Color is green if test passes, yellow if test is
skipped, and red if the test fails or crashes. Summary line contains
counts of the statuses of the tests subtests or the test itself if it
has no subtests.
"Testing complete. Passed: 2, Failed: 0, Crashed: 0, Skipped: 0,
Errors: 0"
test - Test object representing current test being printed
if test.status == TestStatus.SUCCESS:
color =
elif test.status in (TestStatus.SKIPPED, TestStatus.NO_TESTS):
color = stdout.yellow
color =
stdout.print_with_timestamp(color(f'Testing complete. {test.counts}'))
# Summarize failures that might have gone off-screen since we had a lot
# of tests (arbitrarily defined as >=100 for now).
if test.ok_status() or < 100:
summarized = _summarize_failed_tests(test)
if not summarized:
# Other methods:
def bubble_up_test_results(test: Test) -> None:
If the test has subtests, add the test counts of the subtests to the
test and check if any of the tests crashed and if so set the test
status to crashed. Otherwise if the test has no subtests add the
status of the test to the test counts.
test - Test object for current test being parsed
subtests = test.subtests
counts = test.counts
status = test.status
for t in subtests:
if == 0:
elif test.counts.get_status() == TestStatus.TEST_CRASHED:
test.status = TestStatus.TEST_CRASHED
def parse_test(lines: LineStream, expected_num: int, log: List[str], is_subtest: bool) -> Test:
Finds next test to parse in LineStream, creates new Test object,
parses any subtests of the test, populates Test object with all
information (status, name) about the test and the Test objects for
any subtests, and then returns the Test object. The method accepts
three formats of tests:
Accepted test formats:
- Main KTAP/TAP header
KTAP version 1
- Subtest header (must include either the KTAP version line or
"# Subtest" header line)
Example (preferred format with both KTAP version line and
"# Subtest" line):
KTAP version 1
# Subtest: name
ok 1 name
Example (only "# Subtest" line):
# Subtest: name
ok 1 name
Example (only KTAP version line, compliant with KTAP v1 spec):
KTAP version 1
ok 1 name
- Test result line
ok 1 - test
lines - LineStream of KTAP output to parse
expected_num - expected test number for test to be parsed
log - list of strings containing any preceding diagnostic lines
corresponding to the current test
is_subtest - boolean indicating whether test is a subtest
Test object populated with characteristics and any subtests
test = Test()
if not is_subtest:
# If parsing the main/top-level test, parse KTAP version line and
# test plan = "main"
ktap_line = parse_ktap_header(lines, test)
parse_test_plan(lines, test)
parent_test = True
# If not the main test, attempt to parse a test header containing
# the KTAP version line and/or subtest header line
ktap_line = parse_ktap_header(lines, test)
subtest_line = parse_test_header(lines, test)
parent_test = (ktap_line or subtest_line)
if parent_test:
# If KTAP version line and/or subtest header is found, attempt
# to parse test plan and print test header
parse_test_plan(lines, test)
expected_count = test.expected_count
subtests = []
test_num = 1
while parent_test and (expected_count is None or test_num <= expected_count):
# Loop to parse any subtests.
# Break after parsing expected number of tests or
# if expected number of tests is unknown break when test
# result line with matching name to subtest header is found
# or no more lines in stream.
sub_log = parse_diagnostic(lines)
sub_test = Test()
if not lines or (peek_test_name_match(lines, test) and
if expected_count and test_num <= expected_count:
# If parser reaches end of test before
# parsing expected number of subtests, print
# crashed subtest and record error
test.add_error('missing expected subtest!')
sub_test = parse_test(lines, test_num, sub_log, True)
test_num += 1
test.subtests = subtests
if is_subtest:
# If not main test, look for test result line
if != "" and not peek_test_name_match(lines, test):
test.add_error('missing subtest result line!')
parse_test_result(lines, test, expected_num)
# Check for there being no subtests within parent test
if parent_test and len(subtests) == 0:
# Don't override a bad status if this test had one reported.
# Assumption: no subtests means CRASHED is from Test.__init__()
if test.status in (TestStatus.TEST_CRASHED, TestStatus.SUCCESS):
test.status = TestStatus.NO_TESTS
test.add_error('0 tests run!')
# Add statuses to TestCounts attribute in Test object
if parent_test and is_subtest:
# If test has subtests and is not the main test object, print
# footer.
elif is_subtest:
return test
def parse_run_tests(kernel_output: Iterable[str]) -> Test:
Using kernel output, extract KTAP lines, parse the lines for test
results and print condensed test results and summary line.
kernel_output - Iterable object contains lines of kernel output
Test - the main test object with all subtests.
lines = extract_tap_lines(kernel_output)
test = Test()
if not lines: = '<missing>'
test.add_error('Could not find any KTAP output. Did any KUnit tests run?')
test.status = TestStatus.FAILURE_TO_PARSE_TESTS
test = parse_test(lines, 0, [], False)
if test.status != TestStatus.NO_TESTS:
test.status = test.counts.get_status()
return test