sglang/test/registered/unit/README.md

Unit Tests

Component-level tests that do not launch a server or load model weights. Tests can use CPU or GPU — the key criterion is no server process.

Quick Start

1. Find the source file under python/sglang/srt/.
2. Create the corresponding test here, mirroring the source tree:

   srt/mem_cache/radix_cache.py       →  unit/mem_cache/test_radix_cache.py
   srt/sampling/sampling_params.py    →  unit/sampling/test_sampling_params.py
   

3. Register for CI at the top of the file (after imports, before test classes):

   from sglang.test.ci.ci_register import register_cpu_ci
   register_cpu_ci(est_time=5, suite="stage-a-cpu-only")
   # or: register_cuda_ci(est_time=10, suite="stage-b-test-small-1-gpu")
   

4. Run locally:

   pytest test/registered/unit/ -v            # all unit tests
   pytest test/registered/unit/mem_cache/ -v  # one module
   

5. Run with coverage:

   # summary
   pytest test/registered/unit/ --cov --cov-config=.coveragerc -v
   
   # PR incremental check (require ≥60% on changed lines)
   pytest test/registered/unit/ --cov --cov-config=.coveragerc --cov-report=xml
   diff-cover coverage.xml --compare-branch=origin/main --fail-under=60
   

Example

"""Unit tests for <module> — no server, no model loading."""

from sglang.test.ci.ci_register import register_cpu_ci

register_cpu_ci(est_time=5, suite="stage-a-cpu-only")

import unittest

from sglang.srt.<module> import TargetClass


class TestTargetClass(unittest.TestCase):
    def test_basic_behavior(self):
        obj = TargetClass(...)
        self.assertEqual(obj.method(), expected)


if __name__ == "__main__":
    unittest.main()

Rules

• No popen_launch_server() or Engine(...).
• No model weight loading.
• Use unittest.TestCase or CustomTestCase (from sglang.test.test_utils, adds CI retry).
• Use unittest.mock for dependencies that are expensive to construct.