Files
sglang/test/registered/unit
laoyao0822 c9a39ccdd2 Preserve decode suffix KV locations after cache hits
Decode queue compaction receives req_to_token rows after the prefill side has already populated cached prefix slots.  Cache-hit requests therefore need the extend/suffix slice, not the leading prefix slice, when building the prebuilt transfer chunk.

Constraint: Prefill/decode disaggregation shares req_to_token rows across cached prefix and new suffix positions.

Rejected: Keep slicing from zero | cache-hit requests would copy prefix KV locs into the prebuilt suffix chunk.

Confidence: medium

Scope-risk: narrow

Directive: Do not change prepare_for_prebuilt slicing without testing cache-hit req_to_token layouts.

Tested: python -m py_compile on changed runtime files.

Not-tested: Local pytest blocked before collection by missing orjson dependency.
(cherry picked from commit 416112b617fabe71e8cff7484794af73f3e84440)
2026-06-08 00:17:28 +08:00
..

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-test-cpu")
    # or: register_cuda_ci(est_time=10, suite="stage-b-test-1-gpu-small")
    
  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-test-cpu")

import unittest

from sglang.srt.<module> import TargetClass
from sglang.test.test_utils import CustomTestCase


class TestTargetClass(CustomTestCase):
    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 CustomTestCase (from sglang.test.test_utils, adds CI retry).
  • Use unittest.mock for dependencies that are expensive to construct.