test: split llm-core temperature tests (#4935)

tests/test_llm_core_temperature_anthropic.py

@@ -0,0 +1,34 @@
+"""Regression tests: Anthropic temperature clamping.
+
+Anthropic rejects temperature values outside [0.0, 1.0]. The payload builder
+must clamp the value to that range before sending rather than letting the API
+return HTTP 400.
+"""
+from src import llm_core
+
+
+def _anthropic_payload(temperature):
+    return llm_core._build_anthropic_payload(
+        "claude-3-5-sonnet",
+        [{"role": "user", "content": "Hi"}],
+        temperature,
+        max_tokens=5,
+    )
+
+
+def test_anthropic_payload_clamps_above_one():
+    # Anthropic rejects temperature > 1.0 (e.g. the Nietzsche preset's 1.2).
+    assert _anthropic_payload(1.2)["temperature"] == 1.0
+
+
+def test_anthropic_payload_keeps_in_range():
+    assert _anthropic_payload(0.7)["temperature"] == 0.7
+
+
+def test_anthropic_payload_clamps_negative():
+    assert _anthropic_payload(-0.5)["temperature"] == 0.0
+
+
+def test_anthropic_payload_none_temperature_does_not_crash():
+    payload = _anthropic_payload(None)
+    assert payload["temperature"] is None