Add remove_finalizer function

AUTHORS

@@ -285,6 +285,7 @@ Roberto Polli
 Roland Puntaier
 Romain Dorgueil
 Roman Bolshakov
+Roni Kishner
 Ronny Pfannschmidt
 Ross Lawley
 Ruaridh Williamson

doc/en/how-to/fixtures.rst

@@ -730,6 +730,11 @@ Here's how the previous example would look using the ``addfinalizer`` method:
 It's a bit longer than yield fixtures and a bit more complex, but it
 does offer some nuances for when you're in a pinch.
 
+In addition you can use the remove_finalizer method to remove a finalizer you added
+to the teardown stage.
+The remove_finalizer method will remove the first finalizer match it finds and return True,
+if no match was found the function will return None.
+
 .. code-block:: pytest
 
    $ pytest -q test_emaillib.py

src/_pytest/fixtures.py

@@ -760,6 +760,11 @@ class SubRequest(FixtureRequest):
         within the requesting test context finished execution."""
         self._fixturedef.addfinalizer(finalizer)
 
+    def remove_finalizer(self, finalizer: Callable[[], object]) -> None:
+        """Remove finalizer/teardown function to be called after the last test
+        within the requesting test context finished execution."""
+        return self._fixturedef.remove_finalizer(finalizer)
+
     def _schedule_finalizers(
         self, fixturedef: "FixtureDef[object]", subrequest: "SubRequest"
     ) -> None:
@@ -1003,6 +1008,12 @@ class FixtureDef(Generic[FixtureValue]):
     def addfinalizer(self, finalizer: Callable[[], object]) -> None:
         self._finalizers.append(finalizer)
 
+    def remove_finalizer(self, finalizer: Callable[[], object]) -> None:
+        for finalizer_index, finalizer_func in enumerate(self._finalizers):
+            if finalizer_func.__qualname__ == finalizer.__qualname__:
+                del self._finalizers[finalizer_index]
+                return True
+
     def finish(self, request: SubRequest) -> None:
         exc = None
         try:

src/_pytest/runner.py

@@ -503,6 +503,20 @@ class SetupState:
         assert node in self.stack, (node, self.stack)
         self.stack[node][0].append(finalizer)
 
+    def remove_finalizer(self, finalizer: Callable[[], object], node: Node) -> None:
+        """Remove a finalizer in the given node by name.
+
+        The node must be currently active in the stack.
+        The first finalizer by name will be removed.
+        """
+        assert node and not isinstance(node, tuple)
+        assert callable(finalizer)
+        assert node in self.stack, (node, self.stack)
+        for finalizer_index, finalizer_func in enumerate(self.stack[node][0]):
+            if finalizer_func.__qualname__ == finalizer.__qualname__:
+                del self.stack[node][0][finalizer_index]
+                return True
+
     def teardown_exact(self, nextitem: Optional[Item]) -> None:
         """Teardown the current stack up until reaching nodes that nextitem
         also descends from.

testing/python/fixtures.py

@@ -857,11 +857,33 @@ class TestRequestBasic:
         parent = item.getparent(pytest.Module)
         assert parent is not None
         teardownlist = parent.obj.teardownlist
+        item.session._setupstate.teardown_exact(None)
+        assert teardownlist == [1]
+
+    def test_request_remove_finalizer(self, pytester: Pytester) -> None:
+        item = pytester.getitem(
+            """
+            import pytest
+            teardownlist = []
+            @pytest.fixture
+            def something(request):
+                request.addfinalizer(lambda: teardownlist.append(1))
+                request.remove_finalizer(lambda: teardownlist.append(1))
+            def test_func(something): pass
+        """
+        )
+        assert isinstance(item, Function)
+        item.session._setupstate.setup(item)
+        item._request._fillfixtures()
+        # successively check finalization calls
+        parent = item.getparent(pytest.Module)
+        assert parent is not None
+        teardownlist = parent.obj.teardownlist
         ss = item.session._setupstate
         assert not teardownlist
         ss.teardown_exact(None)
         print(ss.stack)
-        assert teardownlist == [1]
+        assert teardownlist == []
 
     def test_request_addfinalizer_failing_setup(self, pytester: Pytester) -> None:
         pytester.makepyfile(