[verified] feat: complete Ralph task workstreams

tests/test_activation_compression.py

@@ -0,0 +1,63 @@
+"""Trace-driven activation-compression policy units."""
+
+import os
+
+import pytest
+
+from meshnet_node.activation_compression import (
+    CompressionPolicies,
+    CompressionPolicy,
+    compress_activation,
+    decompress_activation,
+)
+
+
+def test_compressible_body_uses_zstd_when_it_clears_savings_policy():
+    body = b"activation" * 20_000
+    result = compress_activation(body, CompressionPolicy(min_input_bytes=1, min_savings_bytes=100))
+    assert result.encoding == "zstd"
+    assert result.output_bytes < result.input_bytes
+    assert decompress_activation(result.body, result.encoding).body == body
+
+
+def test_incompressible_body_stays_raw_after_measured_trial():
+    body = os.urandom(32 * 1024)
+    result = compress_activation(body, CompressionPolicy(min_input_bytes=1, min_savings_bytes=1))
+    assert result.encoding is None
+    assert result.body == body
+    assert result.decision == "below_savings"
+
+
+def test_small_body_uses_raw_fast_path_without_zstd_trial():
+    body = b"x" * 1024
+    result = compress_activation(body, CompressionPolicy(min_input_bytes=2048))
+    assert result.encoding is None
+    assert result.decision == "below_min_input"
+    assert result.elapsed_seconds >= 0
+
+
+def test_threshold_requires_both_byte_and_ratio_savings():
+    body = b"a" * 4096
+    result = compress_activation(
+        body, CompressionPolicy(min_input_bytes=1, min_savings_bytes=len(body), min_savings_ratio=0),
+    )
+    assert result.encoding is None
+    assert result.decision == "below_savings"
+
+
+def test_malformed_zstd_and_legacy_raw_bodies_are_handled_explicitly():
+    assert decompress_activation(b"legacy", None).body == b"legacy"
+    with pytest.raises(ValueError, match="invalid zstd activation body"):
+        decompress_activation(b"not a zstd frame", "zstd")
+    with pytest.raises(ValueError, match="unsupported"):
+        decompress_activation(b"body", "gzip")
+
+
+def test_prefill_decode_and_route_conditions_have_independent_config(monkeypatch):
+    policies = CompressionPolicies()
+    assert policies.for_condition("relay", "prefill").min_input_bytes < policies.for_condition("relay", "decode").min_input_bytes
+    monkeypatch.setenv("MESHNET_COMPRESSION_RELAY_DECODE_MIN_INPUT_BYTES", "123")
+    monkeypatch.setenv("MESHNET_COMPRESSION_LAN_PREFILL_ENABLED", "false")
+    assert policies.for_condition("relay", "decode").min_input_bytes == 123
+    assert not policies.for_condition("lan", "prefill").enabled
+    assert policies.for_condition("benchmark", "prefill").enabled