| 1 | """Integration test: ``cluster_kl`` end-to-end on a real tiny model. |
| 2 | |
| 3 | Mirrors ``test_external_perplexity_e2e`` — the sprint file for S16 |
| 4 | explicitly lists this as a DoD item but the fixture was never shipped. |
| 5 | |
| 6 | The test: |
| 7 | |
| 8 | 1. Builds a small random LoRA on SmolLM2-135M (same template as |
| 9 | ``test_external_perplexity_e2e``). |
| 10 | 2. Runs ``cluster_kl`` with a 16-prompt two-topic set (animals + |
| 11 | programming) — split the ft signal across topics so the specificity |
| 12 | ratio has a chance to be meaningfully non-0.5. |
| 13 | 3. Asserts the probe terminates in a non-ERROR verdict, the specificity |
| 14 | is finite and in ``[0, 1]``, and when preceded by ``null_adapter`` in |
| 15 | a suite the z-score field is populated. |
| 16 | |
| 17 | Needs the ``[semsim]`` extra at runtime (sentence-transformers + |
| 18 | scikit-learn). We assume integration runners install those; skip |
| 19 | gracefully when they don't. |
| 20 | """ |
| 21 | |
| 22 | from __future__ import annotations |
| 23 | |
| 24 | import math |
| 25 | from collections.abc import Iterator |
| 26 | from pathlib import Path |
| 27 | |
| 28 | import pytest |
| 29 | |
| 30 | from dlm_sway.backends.hf import HuggingFaceDifferentialBackend |
| 31 | from dlm_sway.core.model import ModelSpec |
| 32 | from dlm_sway.core.result import Verdict |
| 33 | from dlm_sway.probes.base import RunContext, build_probe |
| 34 | from dlm_sway.suite.runner import run as run_suite |
| 35 | from dlm_sway.suite.spec import SwaySpec |
| 36 | |
| 37 | pytestmark = [pytest.mark.slow, pytest.mark.online] |
| 38 | |
| 39 | |
| 40 | # 16 prompts split 8/8 across two obvious topics. |
| 41 | _PROMPTS = [ |
| 42 | # Animals (topic A) |
| 43 | "The cat chased the mouse around the house.", |
| 44 | "Dogs wag their tails when they are happy.", |
| 45 | "Elephants never forget a face they have seen.", |
| 46 | "Lions hunt in packs called prides.", |
| 47 | "Horses gallop across open fields.", |
| 48 | "Sharks have rows of sharp teeth.", |
| 49 | "Bees pollinate flowers as they gather nectar.", |
| 50 | "Owls hunt small rodents at night.", |
| 51 | # Programming (topic B) |
| 52 | "Write a Python decorator that logs every call.", |
| 53 | "Implement binary search in Rust.", |
| 54 | "Debug a segmentation fault in C++ pointer arithmetic.", |
| 55 | "Explain ownership semantics in Rust.", |
| 56 | "Refactor this JavaScript callback hell into promises.", |
| 57 | "Optimize the SQL query by adding an index.", |
| 58 | "Profile the memory usage of a Go program.", |
| 59 | "Write unit tests for a REST API endpoint.", |
| 60 | ] |
| 61 | |
| 62 | |
| 63 | def _build_random_lora_adapter(base_dir: Path, out_dir: Path) -> None: |
| 64 | import torch |
| 65 | from peft import LoraConfig, get_peft_model |
| 66 | from transformers import AutoModelForCausalLM, AutoTokenizer |
| 67 | |
| 68 | torch.manual_seed(0) |
| 69 | tokenizer = AutoTokenizer.from_pretrained(str(base_dir)) |
| 70 | if tokenizer.pad_token_id is None: |
| 71 | tokenizer.pad_token = tokenizer.eos_token |
| 72 | base = AutoModelForCausalLM.from_pretrained(str(base_dir), torch_dtype=torch.float32) |
| 73 | cfg = LoraConfig( |
| 74 | r=8, |
| 75 | lora_alpha=16, |
| 76 | target_modules=["q_proj", "v_proj"], |
| 77 | lora_dropout=0.0, |
| 78 | bias="none", |
| 79 | task_type="CAUSAL_LM", |
| 80 | ) |
| 81 | peft_model = get_peft_model(base, cfg) |
| 82 | with torch.no_grad(): |
| 83 | for name, param in peft_model.named_parameters(): |
| 84 | if "lora_B" in name: |
| 85 | param.copy_(torch.randn_like(param) * 0.05) |
| 86 | peft_model.save_pretrained(str(out_dir)) |
| 87 | tokenizer.save_pretrained(str(out_dir)) |
| 88 | |
| 89 | |
| 90 | @pytest.fixture(scope="module") |
| 91 | def random_adapter(tiny_model_dir: Path, tmp_path_factory: pytest.TempPathFactory) -> Path: |
| 92 | adapter_dir = tmp_path_factory.mktemp("cluster-kl-random-adapter") |
| 93 | _build_random_lora_adapter(tiny_model_dir, adapter_dir) |
| 94 | return adapter_dir |
| 95 | |
| 96 | |
| 97 | @pytest.fixture(scope="module") |
| 98 | def hf_backend( |
| 99 | tiny_model_dir: Path, random_adapter: Path |
| 100 | ) -> Iterator[HuggingFaceDifferentialBackend]: |
| 101 | backend = HuggingFaceDifferentialBackend( |
| 102 | base_spec=ModelSpec(base=str(tiny_model_dir), kind="hf", dtype="fp32", device="cpu"), |
| 103 | adapter_path=random_adapter, |
| 104 | ) |
| 105 | yield backend |
| 106 | backend.close() |
| 107 | |
| 108 | |
| 109 | def test_probe_runs_on_real_backend(hf_backend: HuggingFaceDifferentialBackend) -> None: |
| 110 | pytest.importorskip("sklearn") |
| 111 | pytest.importorskip("sentence_transformers") |
| 112 | |
| 113 | probe, spec = build_probe( |
| 114 | { |
| 115 | "name": "ck", |
| 116 | "kind": "cluster_kl", |
| 117 | "prompts": _PROMPTS, |
| 118 | "num_clusters": 2, |
| 119 | "min_prompts": 16, |
| 120 | } |
| 121 | ) |
| 122 | ctx = RunContext(backend=hf_backend) |
| 123 | result = probe.run(spec, ctx) |
| 124 | |
| 125 | assert result.verdict != Verdict.ERROR, f"probe errored: {result.message}" |
| 126 | # Under a small random LoRA we don't know the specificity sign; |
| 127 | # just pin that it's finite and in [0, 1]. |
| 128 | assert result.raw is not None |
| 129 | assert math.isfinite(result.raw) |
| 130 | assert 0.0 <= result.raw <= 1.0 |
| 131 | assert result.evidence["num_clusters"] == 2 |
| 132 | assert result.evidence["num_prompts"] == 16 |
| 133 | per_cluster = result.evidence["per_cluster_mean_kl"] |
| 134 | assert len(per_cluster) == 2 |
| 135 | |
| 136 | |
| 137 | def test_null_calibration_lights_up_zscore( |
| 138 | hf_backend: HuggingFaceDifferentialBackend, |
| 139 | ) -> None: |
| 140 | """null_adapter → cluster_kl produces a z_score end-to-end.""" |
| 141 | pytest.importorskip("sklearn") |
| 142 | pytest.importorskip("sentence_transformers") |
| 143 | |
| 144 | raw_spec = SwaySpec.model_validate( |
| 145 | { |
| 146 | "version": 1, |
| 147 | "models": { |
| 148 | "base": {"base": "placeholder"}, |
| 149 | "ft": {"base": "placeholder", "adapter": "/tmp/placeholder"}, |
| 150 | }, |
| 151 | "suite": [ |
| 152 | {"name": "null", "kind": "null_adapter", "runs": 2, "cache": False}, |
| 153 | { |
| 154 | "name": "ck", |
| 155 | "kind": "cluster_kl", |
| 156 | "prompts": _PROMPTS, |
| 157 | "num_clusters": 2, |
| 158 | "min_prompts": 16, |
| 159 | "assert_z_gte": -100.0, # permissive — just want z populated |
| 160 | }, |
| 161 | ], |
| 162 | } |
| 163 | ) |
| 164 | result = run_suite(raw_spec, hf_backend) |
| 165 | assert len(result.probes) == 2 |
| 166 | null_result = result.probes[0] |
| 167 | ck_result = result.probes[1] |
| 168 | assert null_result.verdict == Verdict.PASS |
| 169 | assert ck_result.verdict != Verdict.ERROR |
| 170 | assert ck_result.z_score is not None, ( |
| 171 | f"cluster_kl should have z-scored against null baseline; " |
| 172 | f"evidence={ck_result.evidence}, message={ck_result.message}" |
| 173 | ) |
| 174 | assert math.isfinite(ck_result.z_score) |