From 75a91147098db84588932ae843e33f9b71c986ec Mon Sep 17 00:00:00 2001
From: Jan Petykiewicz <jan@mpxd.net>
Date: Wed, 1 Apr 2026 21:16:03 -0700
Subject: [PATCH] [bezier] validate weights

---
 masque/test/test_utils.py | 16 ++++++++++++++++
 masque/utils/curves.py    |  7 +++++++
 2 files changed, 23 insertions(+)

diff --git a/masque/test/test_utils.py b/masque/test/test_utils.py
index 50b700b..0511a24 100644
--- a/masque/test/test_utils.py
+++ b/masque/test/test_utils.py
@@ -3,9 +3,12 @@ from pathlib import Path
 import numpy
 from numpy.testing import assert_equal, assert_allclose
 from numpy import pi
+import pytest
 
 from ..utils import remove_duplicate_vertices, remove_colinear_vertices, poly_contains_points, rotation_matrix_2d, apply_transforms, DeferredDict
 from ..file.utils import tmpfile
+from ..utils.curves import bezier
+from ..error import PatternError
 
 
 def test_remove_duplicate_vertices() -> None:
@@ -91,6 +94,19 @@ def test_apply_transforms_advanced() -> None:
     assert_allclose(combined[0], [0, 10, pi / 2, 1, 1], atol=1e-10)
 
 
+def test_bezier_validates_weight_length() -> None:
+    with pytest.raises(PatternError, match='one entry per control point'):
+        bezier([[0, 0], [1, 1]], [0, 0.5, 1], weights=[1])
+
+    with pytest.raises(PatternError, match='one entry per control point'):
+        bezier([[0, 0], [1, 1]], [0, 0.5, 1], weights=[1, 2, 3])
+
+
+def test_bezier_accepts_exact_weight_count() -> None:
+    samples = bezier([[0, 0], [1, 1]], [0, 0.5, 1], weights=[1, 2])
+    assert_allclose(samples, [[0, 0], [2 / 3, 2 / 3], [1, 1]], atol=1e-10)
+
+
 def test_deferred_dict_accessors_resolve_values_once() -> None:
     calls = 0
 
diff --git a/masque/utils/curves.py b/masque/utils/curves.py
index 2348678..3a7671b 100644
--- a/masque/utils/curves.py
+++ b/masque/utils/curves.py
@@ -2,6 +2,8 @@ import numpy
 from numpy.typing import ArrayLike, NDArray
 from numpy import pi
 
+from ..error import PatternError
+
 try:
     from numpy import trapezoid
 except ImportError:
@@ -31,6 +33,11 @@ def bezier(
     tt = numpy.asarray(tt)
     nn = nodes.shape[0]
     weights = numpy.ones(nn) if weights is None else numpy.asarray(weights)
+    if weights.ndim != 1 or weights.shape[0] != nn:
+        raise PatternError(
+            f'weights must be a 1D array with one entry per control point; '
+            f'got shape {weights.shape} for {nn} control points'
+            )
 
     with numpy.errstate(divide='ignore'):
         umul = (tt / (1 - tt)).clip(max=1)