ai: apply changes for #1006 (1 review thread)

Addresses:
  - #4418689780 at src/databricks/sql/parameters/native.py:652

Signed-off-by: peco-engineer-bot[bot] <peco-engineer-bot[bot]@users.noreply.github.com>

Author: peco-engineer-bot[bot]

src/databricks/sql/parameters/native.py

@@ -649,6 +649,20 @@ def __init__(
                 "as integers"
             )
 
+        if self.scale is not None:
+            # Range-check scale before the precision=0 fallback below, so a clearly
+            # invalid scale is reported rather than hidden behind a migration warning.
+            if self.scale < 0:
+                raise ValueError(
+                    "DecimalParameter scale must be >= 0, got {}".format(self.scale)
+                )
+            if self.scale > self.MAX_PRECISION:
+                raise ValueError(
+                    "DecimalParameter scale must be between 0 and {}, got {}".format(
+                        self.MAX_PRECISION, self.scale
+                    )
+                )
+
         if self.precision == 0:
             # Earlier releases treated precision=0 as falsy, i.e. "unset", and inferred
             # the type from the value. Keep that behaviour for now (swapping e.g.
@@ -671,23 +685,13 @@ def __init__(
             # Range-check the raw arguments *before* the legacy swap below, so a call
             # that is simply invalid (rather than written for the legacy convention)
             # gets an error naming the argument the caller actually passed, and no
-            # misleading migration warning.
-            if self.scale < 0:
-                raise ValueError(
-                    "DecimalParameter scale must be >= 0, got {}".format(self.scale)
-                )
+            # misleading migration warning. (scale was range-checked above.)
             if not 1 <= self.precision <= self.MAX_PRECISION:
                 raise ValueError(
                     "DecimalParameter precision must be between 1 and {}, got {}".format(
                         self.MAX_PRECISION, self.precision
                     )
                 )
-            if self.scale > self.MAX_PRECISION:
-                raise ValueError(
-                    "DecimalParameter scale must be between 0 and {}, got {}".format(
-                        self.MAX_PRECISION, self.scale
-                    )
-                )
 
         if self.scale == 0 and self.precision is not None:
             # Earlier releases also treated scale=0 as falsy, i.e. "unset", and

tests/unit/test_parameters.py

@@ -263,6 +263,22 @@ def test_decimal_precision_zero_falls_back_to_inferred_type_with_warning(scale):
     assert p._cast_expr() == "DECIMAL(6,2)"
 
 
+@pytest.mark.parametrize(
+    "scale,match",
+    (
+        (-1, "scale must be >= 0, got -1"),
+        (500, "scale must be between 0 and 38, got 500"),
+    ),
+)
+def test_decimal_precision_zero_with_invalid_scale_raises(scale, match):
+    """An out-of-range scale is rejected even with precision=0, not hidden behind
+    the precision=0 migration warning."""
+    with warnings.catch_warnings():
+        warnings.simplefilter("error", FutureWarning)
+        with pytest.raises(ValueError, match=match):
+            DecimalParameter(Decimal("1.5"), scale=scale, precision=0)
+
+
 @pytest.mark.parametrize(
     "value,precision,expected",
     (