add-test

name	add-test
description	Use when writing tests for EmbodiChain modules, including observation functors, reward functors, solvers, sensors, environments, or any Python module

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/solvers/pytorch_solver.py  →  tests/sim/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
embodichain/lab/gym/envs/tasks/rl/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, sim_device="cpu")
        self.sim = SimulationManager(config)
        # ... setup ...

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

    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)

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

# 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

Convention	Rule
File header	Apache 2.0 copyright block (same 15 lines as source)
File naming	test_<module>.py
Function naming	test_<scenario>
from __future__	Required after header
Magic numbers	Define as named constants with explanatory comments
Simulation tests	Initialize/teardown in setup_method/teardown_method
Pure-logic tests	Use mock objects, no real sim
SceneEntityCfg	Use MagicMock(uid="...") in tests
Assertions	assert, pytest.approx, torch.allclose, pytest.raises
Entry block	if __name__ == "__main__" for visual debugging support

Common Mistakes

Mistake	Fix
Missing Apache header on test file	Copy the 15-line copyright block
Using real SimulationManager for functor tests	Use MockEnv/MockSim — much faster, no GPU needed
Hardcoded numbers without explanation	Define as EXPECTED_DISTANCE = 0.5 # cube at origin, target at (0.5, 0, 0)
Testing multiple concepts in one function	Split into separate test_<scenario> functions
Forgetting teardown_method	Always call self.sim.destroy() in teardown
Not running black on test file	CI checks all files including tests

Quick Reference

Action	Command
Run all tests	pytest tests/
Run single file	pytest tests/<path>/test_<name>.py -v
Run single test	pytest tests/<path>::test_<name> -v
Run with print output	pytest -s tests/<path>/test_<name>.py
Format	black tests/<path>/test_<name>.py