From 0fe311e9598121b459a29f7f61a84c0ef1d14190 Mon Sep 17 00:00:00 2001
From: Obayne <whoban72@gmail.com>
Date: Tue, 23 Sep 2025 02:23:58 -0500
Subject: [PATCH 1/2] feat(cad_core): Add is_parallel function

---
 cad_core/lines.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/cad_core/lines.py b/cad_core/lines.py
index 112eb70..8e7ebb8 100644
--- a/cad_core/lines.py
+++ b/cad_core/lines.py
@@ -152,6 +152,7 @@ def trim_segment_by_cutter(seg: Line, cutter: Line, end: str = "b", tol: float =
 __all__ = [
     "Point",
     "Line",
+    "is_parallel",
     "intersection_line_line",
     "extend_line_end_to_point",
     "extend_line_to_intersection",

From 6cf554d29589fe750774c5f260a1e2207d49c1b9 Mon Sep 17 00:00:00 2001
From: Obayne <whoban72@gmail.com>
Date: Tue, 23 Sep 2025 02:27:20 -0500
Subject: [PATCH 2/2] test(cad_core): Add tests for is_parallel function

Adds tests for the is_parallel function to cover the following scenarios:
---
 tests/cad_core/test_is_parallel.py | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 tests/cad_core/test_is_parallel.py

diff --git a/tests/cad_core/test_is_parallel.py b/tests/cad_core/test_is_parallel.py
new file mode 100644
index 0000000..277ab29
--- /dev/null
+++ b/tests/cad_core/test_is_parallel.py
@@ -0,0 +1,21 @@
+from cad_core.lines import Line, Point, is_parallel
+
+def test_parallel_lines():
+    l1 = Line(Point(0, 0), Point(10, 0))
+    l2 = Line(Point(0, 10), Point(10, 10))
+    assert is_parallel(l1, l2) is True
+
+def test_non_parallel_lines():
+    l1 = Line(Point(0, 0), Point(10, 0))
+    l2 = Line(Point(0, 0), Point(0, 10))
+    assert is_parallel(l1, l2) is False
+
+def test_collinear_lines():
+    l1 = Line(Point(0, 0), Point(10, 0))
+    l2 = Line(Point(20, 0), Point(30, 0))
+    assert is_parallel(l1, l2) is True
+
+def test_nearly_parallel_lines():
+    l1 = Line(Point(0, 0), Point(1000, 0))
+    l2 = Line(Point(0, 1e-10), Point(1000, 1e-10))
+    assert is_parallel(l1, l2) is True