Validate all MM numeric settings up front

Author: WGB5445

examples/write/market_maker_bot.py

@@ -530,10 +530,24 @@ def _env_default_numeric(name: str, default: float | int, caster: type[float] |
 
 
 def _validate_settings(settings: MMSettings) -> None:
-    if not math.isfinite(settings.max_inventory) or settings.max_inventory <= 0:
-        raise ValueError("max_inventory must be a finite value > 0; adjust --max-inventory")
-    if not math.isfinite(settings.max_margin_usage) or settings.max_margin_usage <= 0:
-        raise ValueError("max_margin_usage must be a finite value > 0; adjust --max-margin-usage")
+    errors: list[str] = []
+    finite_positive_fields = (
+        ("spread", settings.spread, "--spread"),
+        ("order_size", settings.order_size, "--order-size"),
+        ("max_inventory", settings.max_inventory, "--max-inventory"),
+        ("skew_per_unit", settings.skew_per_unit, "--skew-per-unit"),
+        ("max_margin_usage", settings.max_margin_usage, "--max-margin-usage"),
+        ("refresh_interval_s", settings.refresh_interval_s, "--refresh-interval"),
+        ("cooldown_s", settings.cooldown_s, "--cooldown"),
+        ("cancel_resync_s", settings.cancel_resync_s, "--cancel-resync"),
+    )
+    for field_name, value, flag in finite_positive_fields:
+        if not math.isfinite(value) or value <= 0:
+            errors.append(f"{field_name} must be a finite value > 0; adjust {flag}")
+    if settings.max_cycles < 0:
+        errors.append("max_cycles must be >= 0; adjust --max-cycles")
+    if errors:
+        raise ValueError("; ".join(errors))
 
 
 async def main() -> int:

tests/test_market_maker_bot.py

@@ -178,6 +178,17 @@ def test_validate_settings_rejects_non_finite_limits() -> None:
         mm._validate_settings(mm.MMSettings(max_margin_usage=float("nan")))
 
 
+def test_validate_settings_reports_multiple_invalid_fields() -> None:
+    mm = _load_market_maker_module()
+    bad = mm.MMSettings(spread=float("nan"), max_margin_usage=0.0, max_cycles=-1)
+    with pytest.raises(ValueError) as excinfo:
+        mm._validate_settings(bad)
+    msg = str(excinfo.value)
+    assert "spread must be a finite value > 0; adjust --spread" in msg
+    assert "max_margin_usage must be a finite value > 0; adjust --max-margin-usage" in msg
+    assert "max_cycles must be >= 0; adjust --max-cycles" in msg
+
+
 def test_decimal_rounding_helpers_stable_for_tiny_values() -> None:
     mm = _load_market_maker_module()
     down = mm._round_to_tick_size_decimal(
@@ -284,8 +295,8 @@ async def _fake_run_cycle(*args, **kwargs):
             skew_per_unit=0.0001,
             max_margin_usage=0.5,
             refresh_interval=0.01,
-            cooldown=0.0,
-            cancel_resync=0.0,
+            cooldown=0.01,
+            cancel_resync=0.01,
             max_cycles=1,
             dry_run=True,
         ),