add pytest-subtests support

.github/workflows/tests.yml

@@ -29,7 +29,7 @@ jobs:
 
       - name: Run tox
         # Run tox using the version of Python in `PATH`
-        run: tox -e py
+        run: tox run-parallel -e py,subtests
 
   coverage:
     needs: build
@@ -47,7 +47,7 @@ jobs:
         run: pip install tox
 
       - name: Collect coverage data
-        run: tox -e coverage
+        run: tox run-parallel -e coverage,subtests-coverage
 
       - name: Combine coverage & fail if it's <100%
         run: |

pyproject.toml

@@ -34,6 +34,7 @@ tap = "pytest_tap.plugin"
 [dependency-groups]
 dev = [
     "pytest-tap",
+    "pytest-subtests",
     "tox>=4.24.1",
 ]
 
@@ -55,6 +56,7 @@ packages = ["pytest_tap"]
 
 [tool.pytest.ini_options]
 pythonpath = [".", "src"]
+markers = ["subtests"]
 
 [tool.uv.sources]
 pytest-tap = { workspace = true }

src/pytest_tap/plugin.py

@@ -36,13 +36,17 @@ def __init__(self, config: pytest.Config) -> None:
     def pytest_runtestloop(self, session):
         """Output the plan line first."""
         option = session.config.option
-        if option.tap_stream or option.tap_combined:
+        if (option.tap_stream or option.tap_combined) and not (
+            session.config.pluginmanager.has_plugin("subtests")
+        ):
             self._tracker.set_plan(session.testscollected)
 
     @pytest.hookimpl(optionalhook=True)
     def pytest_xdist_node_collection_finished(self, node, ids):
         """Output the plan line first when using xdist."""
-        if self._tracker.streaming or self._tracker.combined:
+        if (self._tracker.streaming or self._tracker.combined) and not (
+            node.config.pluginmanager.has_plugin("subtests")
+        ):
             self._tracker.set_plan(len(ids))
 
     @pytest.hookimpl()
@@ -57,6 +61,10 @@ def pytest_runtest_logreport(self, report: pytest.TestReport):
             return
 
         description = str(report.location[0]) + "::" + str(report.location[2])
+        if hasattr(report, "sub_test_description"):
+            # Handle pytest-subtests plugin
+            description += report.sub_test_description()
+
         testcase = report.location[0]
 
         # Handle xfails first because they report in unusual ways.
@@ -116,6 +124,9 @@ def pytest_runtest_logreport(self, report: pytest.TestReport):
     @pytest.hookimpl()
     def pytest_unconfigure(self, config: pytest.Config):
         """Dump the results."""
+        if self._tracker.combined and config.pluginmanager.has_plugin("subtests"):
+            # Force Tracker to write plan at beginning of file
+            self._tracker.set_plan(self._tracker.combined_line_number)
         self._tracker.generate_tap_reports()
 
 

tests/test_subtests.py

@@ -0,0 +1,61 @@
+import pytest
+from tap.tracker import ENABLE_VERSION_13
+
+
+@pytest.mark.subtests
+def test_log_subtests_stream(testdir):
+    """Subtests are added individually to stream."""
+    testdir.makepyfile(
+        """
+        import pytest
+
+        def test_subtests(subtests):
+            for i in range(2):
+                with subtests.test(msg="sub_msg", i=i):
+                    assert i % 2 == 0
+    """
+    )
+    result = testdir.runpytest_subprocess("--tap")
+
+    result.stdout.fnmatch_lines(
+        [
+            "ok 1 test_log_subtests_stream.py::test_subtests[sub_msg] (i=0)",
+            "not ok 2 test_log_subtests_stream.py::test_subtests[sub_msg] (i=1)",
+            "ok 3 test_log_subtests_stream.py::test_subtests",
+            "1..3",
+        ]
+    )
+
+
+@pytest.mark.subtests
+def test_log_subtests_combined(testdir):
+    """Subtests are added individually to combined."""
+    testdir.makepyfile(
+        """
+        import pytest
+
+        def test_subtests(subtests):
+            for i in range(2):
+                with subtests.test(msg="sub_msg", i=i):
+                    assert i % 2 == 0
+    """
+    )
+    testdir.runpytest_subprocess("--tap-outdir", "subtest-results", "--tap-combined")
+    outdir = testdir.tmpdir.join("subtest-results")
+    testresults = outdir.join("testresults.tap")
+    assert testresults.check()
+    actual_results = [
+        line.strip() for line in testresults.readlines() if not line.startswith("#")
+    ]
+
+    expected_results = [
+        "1..3",
+        "ok 1 test_log_subtests_combined.py::test_subtests[sub_msg] (i=0)",
+        "not ok 2 test_log_subtests_combined.py::test_subtests[sub_msg] (i=1)",
+        "ok 3 test_log_subtests_combined.py::test_subtests",
+    ]
+
+    # If the dependencies for version 13 happen to be installed, tweak the output.
+    if ENABLE_VERSION_13:
+        expected_results.insert(0, "TAP version 13")
+    assert actual_results == expected_results

tests/test_xdist.py

@@ -23,6 +23,7 @@ def test_sets_plan_streaming(combined, stream, expected):
     config.option.tap_stream = stream
     plugin = TAPPlugin(config)
     node = mock.Mock()
+    node.config.pluginmanager.has_plugin = lambda x: x != "subtests"
     test_ids = ["a", "b", "c"]
 
     plugin.pytest_xdist_node_collection_finished(node, test_ids)

tox.ini

@@ -1,15 +1,30 @@
 [tox]
 envlist =
+    subtests
     coverage
 
 [testenv]
 deps =
     pytest
-commands = pytest --tap-combined {posargs}
+commands = pytest -m 'not subtests' --tap-combined {posargs}
+
+[testenv:subtests]
+deps =
+    pytest
+    pytest-subtests
+commands = pytest -m 'subtests' --tap-combined {posargs}
 
 [testenv:coverage]
 deps =
     pytest
     pytest-cov
 commands =
-    pytest --cov=pytest_tap --cov-report xml --cov-report term
+    pytest -m 'not subtests' --cov=pytest_tap --cov-append --cov-report xml --cov-report term
+
+[testenv:subtests-coverage]
+deps =
+    pytest
+    pytest-subtests
+    pytest-cov
+commands =
+    pytest -m 'subtests' --cov=pytest_tap --cov-append --cov-report xml --cov-report term