Add Test

Write tests following EmbodiChain's conventions and patterns.

When to Use

• User asks to "add a test", "write tests for X", "test this module"
• A new public module or function needs test coverage
• PR checklist requires tests

Test File Location

Tests mirror the source tree under tests/:

embodichain/lab/sim/motion/solvers/pytorch_solver.py  →  tests/sim/motion/solvers/test_pytorch_solver.py
embodichain/lab/gym/envs/managers/rewards.py    →  tests/gym/envs/managers/test_reward_functors.py
embodichain/toolkits/graspkit/pg_grasp/foo.py   →  tests/toolkits/test_pg_grasp.py
extensions/embodichain_tasks/embodichain_tasks/manipulation/push_cube.py → tests/gym/envs/tasks/test_push_cube.py

Rules:

• File name: test_<module>.py
• Directory path mirrors embodichain/ structure under tests/
• Create __init__.py files in new tests/ subdirectories if needed

Two Test Styles

pytest Style — For Pure-Python Logic (No Sim)

Use when: testing functors, utility functions, pure math, config validation — anything that doesn't need a SimulationManager.

# ----------------------------------------------------------------------------
# Copyright (c) 2021-2026 DexForce Technology Co., Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# ...
# ----------------------------------------------------------------------------

from __future__ import annotations

import pytest
import torch

from embodichain.my_module import my_function


def test_expected_output():
    result = my_function(input_value)
    assert result == expected_value


def test_edge_case():
    result = my_function(edge_input)
    assert result is not None

Class Style — For Sim-Dependent or Ordered Tests

Use when: tests need SimulationManager, GPU setup, or must run in a specific order. Share state via setup_method/teardown_method.

# ----------------------------------------------------------------------------
# Copyright (c) 2021-2026 DexForce Technology Co., Ltd.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# ...
# ----------------------------------------------------------------------------

from __future__ import annotations

import pytest
import torch

from embodichain.lab.sim import SimulationManager, SimulationManagerCfg


class TestMySimComponent:
    def setup_method(self):
        config = SimulationManagerCfg(headless=True, device="cpu")
        self.sim = SimulationManager(config)
        # ... setup ...

    def teardown_method(self):
        self.sim.destroy()
        SimulationManager.flush_cleanup_queue()

    def test_basic_behavior(self):
        result = self.sim.do_something()
        assert result == expected_result

    def test_raises_on_bad_input(self):
        with pytest.raises(ValueError):
            self.sim.do_something(bad_input)

Resource-Aware Test Classification

Use the narrowest test type that proves the behavior:

• Prefer mocks or CPU-only inputs for pure logic and shape validation.
• tests/conftest.py automatically classifies conventional CUDA, renderer, and real-simulation tests. Add @pytest.mark.gpu, @pytest.mark.slow, or @pytest.mark.requires_sim explicitly only when the test's node id/source cannot reveal that requirement (for example, a hidden CUDA helper or an end-to-end toolkit test).

GPU tests are skipped by default to keep normal test runs within the shared VRAM budget. Run them explicitly and serially:

# Default suite: GPU-marked tests are skipped.
pytest tests/

# Dedicated GPU suite. Do not add -n unless pytest-xdist is installed.
pytest tests/ --run-gpu -m gpu

For backend/device matrices, run the complete contract on one representative configuration and use small (one environment, low-resolution) smoke tests for the remaining configurations. Always destroy a real SimulationManager and flush its cleanup queue in teardown.

Task Program and task-configuration tests

Choose the test surface by ownership layer:

For JSON/YAML configuration, test through the same strict loader and component composition used by production. A yaml.safe_load() assertion alone does not prove closed fields, relative component paths, physical scene targets, contracts, catalog coverage, or program preflight.

Add negative coverage for the earliest ownership boundary being changed: unknown fields, missing component files, duplicate inline/component ownership, absent simulation_uid, contract mismatch, unknown Semantic Calls, or missing registered lowerers. Keep live-simulation qualification separate from provider-free decode/compiler tests.

For a complete configured Task Program deployment, use $add-task-program's read-only inspector as a focused smoke check before adding a heavier environment test.

Mocking Patterns for Functor Tests

Most functor tests don't need a live simulation. Use mock objects following the pattern in tests/gym/envs/managers/test_reward_functors.py:

from unittest.mock import MagicMock, Mock


class MockSim:
    """Mock simulation for functor tests."""

    def __init__(self, num_envs: int = 4):
        self.num_envs = num_envs
        self.device = torch.device("cpu")
        self._rigid_objects: dict = {}

    def get_rigid_object(self, uid: str):
        return self._rigid_objects.get(uid)

    def add_rigid_object(self, obj):
        self._rigid_objects[obj.uid] = obj


class MockEnv:
    """Mock environment for functor tests."""

    def __init__(self, num_envs: int = 4):
        self.num_envs = num_envs
        self.device = torch.device("cpu")
        self.sim = MockSim(num_envs)

Key points for mock objects:

• Set num_envs and device attributes (functors use these)
• Mock only the sim methods the functor actually calls
• Use MagicMock(uid="...") for SceneEntityCfg parameters

Steps

1. Identify What to Test

Ask the user:

1. Which module/function? — determines file path
2. Does it need a live simulation? — determines test style
3. Key behaviors to verify — happy path, edge cases, error cases

2. Determine Test File Path

Map the source path to test path:

embodichain/<subpath>/<module>.py  →  tests/<subpath>/test_<module>.py

Check if the test file already exists — append new test classes/functions if so.

3. Choose Test Style

digraph test_style {
    rankdir=LR;
    "Needs SimulationManager?" -> "Class style" [label="yes"];
    "Needs SimulationManager?" -> "pytest style" [label="no"];
    "Tests share state/order?" -> "Class style" [label="yes"];
    "Tests share state/order?" -> "pytest style" [label="no"];
}

4. Write the Test

Use the appropriate template (pytest or class style above).

Rules:

• Apache 2.0 header — required on every test file
• from __future__ import annotations — after header, before imports
• No magic numbers — define expected values as named constants or comment their origin
• Test function names — test_<scenario> (descriptive, not just test_foo)
• One assertion concept per test — don't bundle unrelated checks

5. Add if __name__ == "__main__" Block

Include this for tests that support optional visual/interactive debugging:

if __name__ == "__main__":
    # For visual debugging: set is_visual=True when calling env methods
    test_obj = TestMyComponent()
    test_obj.setup_method()
    # ... manually run test logic ...

6. Run the Test

# Single file
pytest tests/<subpath>/test_<module>.py -v

# Single test function
pytest tests/<subpath>/test_<module>.py::test_expected_output -v

# GPU-specific test
pytest tests/<subpath>/test_<module>.py --run-gpu -m gpu -v

# Single test class method
pytest tests/<subpath>/test_<module>.py::TestMyClass::test_basic_behavior -v

7. Run black

black tests/<subpath>/test_<module>.py

Conventions Summary

Common Mistakes

Quick Reference