♻️ Simplify env var overrides and add tests

tests/e2e/test_spyre_basic.py

@@ -64,39 +64,6 @@ def test_output(model: ModelInfo, tp_size: int, backend: str, cb: int,
                                **kwargs)
 
 
-@pytest.mark.parametrize("backend", [
-    pytest.param(
-        "sendnn_decoder", marks=pytest.mark.spyre, id="sendnn_decoder")
-])
-def test_output_sendnn_decoder(model: ModelInfo,
-                               warmup_shapes: DecodeWarmupShapes, backend: str,
-                               monkeypatch: pytest.MonkeyPatch,
-                               use_llm_cache) -> None:
-    '''
-    Tests the deprecated sendnn_decoder backend, which should fall-back to
-    sendnn
-    '''
-
-    max_new_tokens = warmup_shapes[0][1]
-    prompts = get_chicken_soup_prompts(1)
-
-    vllm_sampling_params = SamplingParams(
-        max_tokens=max_new_tokens,
-        temperature=0,
-        logprobs=0,  # return logprobs of generated tokens only
-        ignore_eos=True)
-
-    validate_vllm_vs_hf_output(model=model,
-                               prompts=prompts,
-                               warmup_shapes=warmup_shapes,
-                               max_model_len=2048,
-                               sampling_params=vllm_sampling_params,
-                               tensor_parallel_size=1,
-                               backend=backend,
-                               monkeypatch=monkeypatch,
-                               max_new_tokens=max_new_tokens)
-
-
 def test_batch_handling(model: ModelInfo, backend: str, cb: int, warmup_shapes,
                         max_num_seqs: int, max_model_len: int,
                         monkeypatch: pytest.MonkeyPatch, use_llm_cache):

tests/utils/test_envs.py

@@ -0,0 +1,50 @@
+"""Tests for our environment configs"""
+
+import os
+
+import pytest
+
+from vllm_spyre import envs
+
+pytestmark = pytest.mark.cpu
+
+
+def test_env_vars_are_cached(monkeypatch):
+    monkeypatch.setenv("VLLM_SPYRE_NUM_CPUS", "42")
+    assert envs.VLLM_SPYRE_NUM_CPUS == 42
+
+    # Future reads don't query the environment every time, so this should not
+    # return the updated value
+    monkeypatch.setenv("VLLM_SPYRE_NUM_CPUS", "77")
+    assert envs.VLLM_SPYRE_NUM_CPUS == 42
+
+
+def test_env_vars_override(monkeypatch):
+    monkeypatch.setenv("VLLM_SPYRE_NUM_CPUS", "42")
+    assert envs.VLLM_SPYRE_NUM_CPUS == 42
+
+    # This override both sets the environment variable and updates our cache
+    envs.override("VLLM_SPYRE_NUM_CPUS", "77")
+    assert envs.VLLM_SPYRE_NUM_CPUS == 77
+    assert os.getenv("VLLM_SPYRE_NUM_CPUS") == "77"
+
+
+def test_env_vars_override_with_bad_value(monkeypatch):
+    monkeypatch.setenv("VLLM_SPYRE_NUM_CPUS", "42")
+    assert envs.VLLM_SPYRE_NUM_CPUS == 42
+
+    # envs.override ensures the value can be parsed correctly
+    with pytest.raises(ValueError, match=r"invalid literal for int"):
+        envs.override("VLLM_SPYRE_NUM_CPUS", "notanumber")
+
+
+def test_env_vars_override_for_invalid_config():
+    with pytest.raises(ValueError, match=r"not a known setting"):
+        envs.override("VLLM_SPYRE_NOT_A_CONFIG", "nothing")
+
+
+def test_sendnn_decoder_backwards_compat(monkeypatch):
+    # configuring the deprecated `sendnn_decoder` backend will swap to the new
+    # `sendnn` backend instead
+    monkeypatch.setenv("VLLM_SPYRE_DYNAMO_BACKEND", "sendnn_decoder")
+    assert envs.VLLM_SPYRE_DYNAMO_BACKEND == "sendnn"

vllm_spyre/envs.py

@@ -33,17 +33,10 @@
 
 def override(name: str, value: str) -> None:
     if name not in environment_variables:
-        raise ValueError(f"The variable {name} is not a known \
-                         setting and cannot be overridden")
-    original_value = os.environ.get(name)
+        raise ValueError(f"The variable {name} is not a known "
+                         "setting and cannot be overridden")
     os.environ[name] = value
-    try:
-        parsed_value = environment_variables[name]()
-        _cache[name] = parsed_value
-    # Changes back avoid polluting the global environment
-    finally:
-        if original_value is not None:
-            os.environ[name] = original_value
+    _cache[name] = environment_variables[name]()
 
 
 def clear_env_cache():