python: test the exposed topology api

Signed-off-by: Tristram Gräbener <tristram+git@tristramg.eu>

Author: Tristramg

python/tests/test_read_topology.py

@@ -0,0 +1,60 @@
+from liblrs_python import Builder, Point, Lrs, SegmentOfTraversal, AnchorOnLrm
+
+def build_lrm() -> Lrs:
+    """Helper function that builds an example LRS
+
+    It has the following topology:
+        3
+        |
+    0---1---2
+
+    0-1-2 is lrm_1
+    1-3 is lrm_2
+    """
+
+
+    builder = Builder()
+
+    p0 = Point(0, 0)
+    p1 = Point(1, 0)
+    p2 = Point(2, 0)
+    p3 = Point(1, 1)
+
+    builder.add_node("0", p0, {})
+    builder.add_node("1", p1, {})
+    builder.add_node("2", p2, {})
+    builder.add_node("3", p3, {})
+
+
+    segment1 = SegmentOfTraversal(builder.add_segment("s1", [p0, p1], 0, 1), False)
+    segment2 = SegmentOfTraversal(builder.add_segment("s2", [p2, p1], 1, 2), False)
+    segment3 = SegmentOfTraversal(builder.add_segment("s1", [p1, p3], 0, 1), False)
+    
+    traversal1 = builder.add_traversal("traversal1", [segment1, segment2])
+    traversal2 = builder.add_traversal("traversal2", [segment3])
+
+    builder.add_lrm("lrm_1", traversal1, [], {})
+    builder.add_lrm("lrm_2", traversal2, [], {})
+
+    return builder.build_lrs({})
+
+
+def test_get_topology():
+    lrs = build_lrm()
+    nodes = lrs.get_nodes()
+    assert len(nodes) == 4
+
+    n0 = lrs.get_node(0)
+    assert n0.id == "0"
+    assert n0.properties == {}
+    assert n0.geometry is not None
+    assert n0.geometry.x == 0
+    assert n0.geometry.y == 0
+
+    segments = lrs.get_segments()
+    assert len(segments) == 3
+
+    segment1 = segments[0]
+    assert segment1.id == "s1"
+    assert segment1.start_node == 0
+    assert segment1.end_node == 1