Fix --last-failed with unittest subtests

AUTHORS

@@ -231,6 +231,7 @@ Jeff Widman
 Jenni Rinker
 Jens Tröger
 Jiajun Xu
+Jinhyuk Sung
 John Eddie Ayson
 John Litborn
 John Towler

changelog/14575.bugfix.rst

@@ -0,0 +1 @@
+``--last-failed`` now reruns ``unittest.TestCase`` tests that contain failed subtests.

src/_pytest/cacheprovider.py

@@ -32,6 +32,7 @@
 from _pytest.nodes import Directory
 from _pytest.nodes import File
 from _pytest.reports import TestReport
+from _pytest.subtests import SubtestReport
 
 
 CACHEDIR_FILES: dict[str, bytes] = {
@@ -319,6 +320,7 @@ def __init__(self, config: Config) -> None:
         self.active = any(config.getoption(key) for key in active_keys)
         assert config.cache
         self.lastfailed: dict[str, bool] = config.cache.get("cache/lastfailed", {})
+        self._tests_with_failed_subtests: set[str] = set()
         self._previously_failed_count: int | None = None
         self._report_status: str | None = None
         self._skipped_files = 0  # count skipped files during collection due to --lf
@@ -346,7 +348,18 @@ def pytest_report_collectionfinish(self) -> str | None:
         return None
 
     def pytest_runtest_logreport(self, report: TestReport) -> None:
-        if (report.when == "call" and report.passed) or report.skipped:
+        if report.when == "setup":
+            self._tests_with_failed_subtests.discard(report.nodeid)
+
+        if isinstance(report, SubtestReport):
+            if report.failed:
+                self._tests_with_failed_subtests.add(report.nodeid)
+                self.lastfailed[report.nodeid] = True
+            return
+
+        if (
+            (report.when == "call" and report.passed) or report.skipped
+        ) and report.nodeid not in self._tests_with_failed_subtests:
             self.lastfailed.pop(report.nodeid, None)
         elif report.failed:
             self.lastfailed[report.nodeid] = True

testing/test_subtests.py

@@ -464,6 +464,34 @@ def test_zaz(self):
             ]
         )
 
+    def test_last_failed(
+        self, pytester: pytest.Pytester, monkeypatch: pytest.MonkeyPatch
+    ) -> None:
+        """Check that --last-failed reruns tests with failed unittest subtests."""
+        monkeypatch.setenv("COLUMNS", "120")
+        pytester.makepyfile(
+            """
+            from unittest import TestCase
+
+            class T(TestCase):
+                def test_foo(self):
+                    for i in range(3):
+                        with self.subTest(index=i):
+                            assert i % 2 == 0
+            """
+        )
+        result = pytester.runpytest("-v")
+        result.stdout.fnmatch_lines(["* 1 failed, 1 passed, 2 subtests passed in *"])
+
+        result = pytester.runpytest("-v", "--last-failed")
+        result.stdout.fnmatch_lines(
+            [
+                "*collected 1 item",
+                "run-last-failure: rerun previous 1 failure",
+                "* 1 failed, 1 passed, 2 subtests passed in *",
+            ]
+        )
+
     def test_passes(
         self, pytester: pytest.Pytester, monkeypatch: pytest.MonkeyPatch
     ) -> None: