Add a fixture-based test with a single variant and mark it with
XFAIL_ADD(). The test intentionally fails and is expected to be
accounted as XFAIL, covering the constructor ordering dependency
between TEST_F() registration and XFAIL_ADD() registration.

Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Tested-by: Bjoern Doebel <doebel@amazon.de>
Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com>
---

v3:
- Rebase on kselftest/fixes.
- Refresh harness-selftest.expected after commit 465b05bae5ac
  ("selftests: harness: Restore order of test functions").
- Add Tested-by from Bjoern Doebel.

v2:
- update Suggested-by address
- update harness-selftest.expected
- verify with 'make run_tests'

 .../kselftest_harness/harness-selftest.c      | 23 +++++++++++++++++++
 .../harness-selftest.expected                 | 13 +++++++----
 2 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/kselftest_harness/harness-selftest.c b/tools/testing/selftests/kselftest_harness/harness-selftest.c
index 3e3033d2745a..93b5a5bbf10a 100644
--- a/tools/testing/selftests/kselftest_harness/harness-selftest.c
+++ b/tools/testing/selftests/kselftest_harness/harness-selftest.c
@@ -158,6 +158,29 @@ TEST(test_result_skip) {
 	ksft_test_result_skip("");
 }
 
+FIXTURE(xfail_ctor_ordering) {
+};
+
+FIXTURE_SETUP(xfail_ctor_ordering) {
+}
+
+FIXTURE_TEARDOWN(xfail_ctor_ordering) {
+}
+
+FIXTURE_VARIANT(xfail_ctor_ordering) {
+	int dummy;
+};
+
+FIXTURE_VARIANT_ADD(xfail_ctor_ordering, only) {
+	.dummy = 0,
+};
+
+TEST_F(xfail_ctor_ordering, expected_fail) {
+	ASSERT_EQ(1, 0);
+}
+
+XFAIL_ADD(xfail_ctor_ordering, only, expected_fail);
+
 int main(int argc, char **argv)
 {
 	/*
diff --git a/tools/testing/selftests/kselftest_harness/harness-selftest.expected b/tools/testing/selftests/kselftest_harness/harness-selftest.expected
index c0a68ec124f8..f8b7cb2812b6 100644
--- a/tools/testing/selftests/kselftest_harness/harness-selftest.expected
+++ b/tools/testing/selftests/kselftest_harness/harness-selftest.expected
@@ -1,6 +1,6 @@
 TAP version 13
-1..19
-# Starting 19 tests from 4 test cases.
+1..20
+# Starting 20 tests from 5 test cases.
 #  RUN           global.standalone_pass ...
 # harness-selftest.c:19:standalone_pass:before
 # harness-selftest.c:23:standalone_pass:after
@@ -93,6 +93,11 @@ ok 18 fixture_parent.pass
 # pass: Test terminated by assertion
 #          FAIL  fixture_setup_failure.pass
 not ok 19 fixture_setup_failure.pass
-# FAILED: 12 / 19 tests passed.
+#  RUN           xfail_ctor_ordering.only.expected_fail ...
+# harness-selftest.c:179:expected_fail:Expected 1 (1) == 0 (0)
+# expected_fail: Test terminated by assertion
+#          FAIL  xfail_ctor_ordering.only.expected_fail
+ok 20 xfail_ctor_ordering.only.expected_fail # XFAIL unknown
+# FAILED: 13 / 20 tests passed.
 # 1 skipped test(s) detected. Consider enabling relevant config options to improve coverage.
-# Totals: pass:9 fail:7 xfail:1 xpass:1 skip:1 error:0
+# Totals: pass:9 fail:7 xfail:2 xpass:1 skip:1 error:0
-- 
2.43.0