add test for path length

tests/test_circle.py

@@ -1,30 +1,34 @@
 from typing import Tuple
 
+import numpy as np
 import pytest
 
 import vsketch
 
-from .utils import bounds_equal, line_count_equal
+from .utils import bounds_equal, length_equal, line_count_equal
 
 
 def test_circle_default(vsk: vsketch.Vsketch) -> None:
     # default should be diameter
     vsk.detail(0.01)  # make sure we have a tight bound match
     vsk.circle(0, 0, 5)
     assert line_count_equal(vsk, 1)
+    assert length_equal(vsk, 5 * np.pi)
     assert bounds_equal(vsk, -2.5, -2.5, 2.5, 2.5)
 
 
 def test_circle_radius(vsk: vsketch.Vsketch) -> None:
     vsk.circle(0, 0, radius=5)
     assert line_count_equal(vsk, 1)
+    assert length_equal(vsk, 5 * 2 * np.pi)
     assert bounds_equal(vsk, -5, -5, 5, 5)
 
 
 def test_circle_diameter(vsk: vsketch.Vsketch) -> None:
     vsk.detail(0.01)  # make sure we have a tight bound match
     vsk.circle(0, 0, diameter=5)
     assert line_count_equal(vsk, 1)
+    assert length_equal(vsk, 5 * np.pi)
     assert bounds_equal(vsk, -2.5, -2.5, 2.5, 2.5)
 
 

tests/test_line.py

@@ -1,7 +1,9 @@
-from .utils import bounds_equal, line_count_equal
+from .utils import bounds_equal, length_equal, line_count_equal, line_exists
 
 
 def test_line(vsk):
     vsk.line(5, 5, 10, 5)
     assert line_count_equal(vsk, 1)
+    assert line_exists(vsk, [5 + 5j, 10 + 5j])
+    assert length_equal(vsk, 5)
     assert bounds_equal(vsk, 5, 5, 10, 5)

tests/test_rect.py

@@ -5,13 +5,14 @@
 
 import vsketch
 
-from .utils import bounds_equal, line_count_equal, line_exists
+from .utils import bounds_equal, length_equal, line_count_equal, line_exists
 
 
 def test_rect_default_success(vsk: vsketch.Vsketch) -> None:
     vsk.rect(0, 0, 2, 4)
     assert line_count_equal(vsk, 1)
     assert line_exists(vsk, np.array([0, 2, 2 + 4j, 4j, 0], dtype=complex), strict=False)
+    assert length_equal(vsk, (2+4)*2)
 
 
 @pytest.mark.parametrize(

tests/utils.py

@@ -20,6 +20,17 @@ def bounds_equal(
     )
 
 
+def length_equal(
+    vsk: vsketch.Vsketch, length: float 
+) -> bool:
+    """Asserts that sketch length is approximately equal to those provided"""
+
+    length_ = vsk.document.length()
+    return bool(
+        length is not None
+        and np.isclose(length_, length, rtol=1e-03)
+    )
+
 def line_count_equal(vsk: vsketch.Vsketch, *args: Union[int, Tuple[int, int]]) -> bool:
     """Asserts that layers have the given number of path. Any number of path count can be
     passed as argument, either as single int (layer ID is then inferred or as (layer_ID, n)