Migrate source/isaaclab/test/sim to launch_kit()

Replace the module-scope AppLauncher construction in the Kit-dependent files
under source/isaaclab/test/sim with launch_kit(), and declare the matching
kit or kit_cameras marker on each file.

Because launch_kit() is idempotent, a pytest process covering several of
these files now boots Kit once instead of once per file. Nothing forces them
into one process yet -- tools/conftest.py still runs a subprocess per file --
so this changes how the files launch Kit, not how CI schedules them.

24 files map to `kit` and 4 to `kit_cameras`. The two groups must not share a
process in that order: a camera-enabled app can serve tests that do not need
cameras, but cameras cannot be enabled after startup, so launch_kit() raises
rather than handing back an app that would silently fail to render.

The transform is applied by tools/codemods/kit_launch_migration.py, added
here because ~125 files in other packages remain to migrate. It edits line
ranges in place rather than round-tripping through ast.unparse, which would
discard comments and isort directives, and it preserves each launch call's
position so the Kit-dependent imports below it still run after Kit starts.

The codemod refuses anything it cannot rewrite without changing behaviour,
and reports it. In particular it rejects a conditional launch such as
`AppLauncher(...).app if _USE_KIT else None`, which test_mjcf_converter.py
and test_urdf_converter.py use so they can run kitlessly when the standalone
importer wheel is installed; collapsing that ternary would have made the boot
unconditional. It also refuses a file that references AppLauncher for
anything other than the launch call, since the import is removed.

Author: mataylor-nvidia

source/isaaclab/test/sim/test_articulation_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import os
 
@@ -21,6 +16,8 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
+pytestmark = pytest.mark.kit
+
 
 def _make_xform(stage, path="/World/Art"):
     UsdGeom.Xform.Define(stage, path)

source/isaaclab/test/sim/test_build_simulation_context_headless.py

@@ -13,21 +13,16 @@
 ``test_build_simulation_context_nonheadless.py``.
 """
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
 from isaaclab.sim.simulation_cfg import SimulationCfg
 from isaaclab.sim.simulation_context import build_simulation_context
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 @pytest.mark.parametrize("gravity_enabled", [True, False])

source/isaaclab/test/sim/test_build_simulation_context_nonheadless.py

@@ -12,21 +12,16 @@
 ``test_build_simulation_context_headless.py``.
 """
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
 from isaaclab.sim.simulation_cfg import SimulationCfg
 from isaaclab.sim.simulation_context import build_simulation_context
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 @pytest.mark.parametrize("gravity_enabled", [True, False])

source/isaaclab/test/sim/test_cloner.py

@@ -5,14 +5,9 @@
 
 """Tests for USD cloner utilities (no PhysX dependency)."""
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 from types import SimpleNamespace
 from unittest.mock import MagicMock
@@ -37,7 +32,7 @@
 )
 from isaaclab.sim import build_simulation_context
 
-pytestmark = [pytest.mark.integration, pytest.mark.isaacsim_ci]
+pytestmark = [pytest.mark.kit, pytest.mark.integration, pytest.mark.isaacsim_ci]
 
 
 @pytest.fixture(params=["cpu", "cuda"])

source/isaaclab/test/sim/test_collision_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
@@ -19,7 +14,7 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 def _make_xform(stage, path="/World/Body"):

source/isaaclab/test/sim/test_joint_drive_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import math
 
@@ -21,7 +16,7 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 def _make_revolute_joint(stage, path="/World/Articulation/joint_0"):

source/isaaclab/test/sim/test_mass_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
@@ -19,7 +14,7 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 def _make_xform(stage, path="/World/Body"):

source/isaaclab/test/sim/test_material_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
@@ -19,7 +14,7 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 # -------------------------------------------------------------------------------------
 # RigidBodyMaterialFragment marker + metadata

source/isaaclab/test/sim/test_mesh_collision_fragments.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import pytest
 
@@ -19,7 +14,7 @@
 import isaaclab.sim as sim_utils
 from isaaclab.sim import SimulationCfg, SimulationContext
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 def _make_xform(stage, path="/World/Mesh"):

source/isaaclab/test/sim/test_mesh_converter.py

@@ -3,14 +3,9 @@
 #
 # SPDX-License-Identifier: BSD-3-Clause
 
-"""Launch Isaac Sim Simulator first."""
+from isaaclab.test.launch import launch_kit
 
-from isaaclab.app import AppLauncher
-
-# launch omniverse app
-simulation_app = AppLauncher(headless=True).app
-
-"""Rest everything follows."""
+launch_kit()
 
 import math
 import os
@@ -27,7 +22,7 @@
 from isaaclab.sim.schemas import MESH_APPROXIMATION_TOKENS, schemas_cfg
 from isaaclab.utils.assets import ISAACLAB_NUCLEUS_DIR, retrieve_file_path
 
-pytestmark = pytest.mark.integration
+pytestmark = [pytest.mark.kit, pytest.mark.integration]
 
 
 def random_quaternion():