test: added tests for edge attributes

Author: ntamas

tests/test_edge_attributes.py

@@ -0,0 +1,90 @@
+from collections.abc import MutableMapping
+
+from pytest import raises
+
+from igraph_ctypes.constructors import create_full_graph, create_famous_graph
+
+
+def test_new_graph_has_no_edge_attributes():
+    g = create_full_graph(4)
+    assert isinstance(g.eattrs, MutableMapping)
+    assert len(g.eattrs) == 0
+
+
+def test_create_edge_attribute():
+    g = create_full_graph(4)
+
+    g.eattrs.set("name", "test")
+    assert list(g.eattrs["name"]) == ["test"] * 6
+
+    g.eattrs.set("weight", (5, 10, 15, 20, 25, 30))
+    assert list(g.eattrs["weight"]) == [5, 10, 15, 20, 25, 30]
+
+    g.eattrs.set("cost", 1)
+    assert list(g.eattrs["cost"]) == [1] * 6
+
+    with raises(RuntimeError, match="length must be"):
+        g.eattrs.set("city", ("London", "Stockholm"))
+
+
+def test_copying_graph_copies_edge_attributes():
+    g = create_famous_graph("zachary")
+    n = g.ecount()
+
+    g.eattrs.set("index", list(range(n)))
+    g.eattrs.set("name", [f"E{i}" for i in range(n)])
+
+    g2 = g.copy()
+    assert sorted(g2.eattrs.keys()) == ["index", "name"]
+    assert list(g2.eattrs["index"]) == list(range(n))
+    assert list(g2.eattrs["name"]) == [f"E{i}" for i in range(n)]
+
+    del g2.eattrs["index"]
+    assert "index" not in g2.eattrs
+    assert list(g.eattrs["index"]) == list(range(n))
+
+
+def test_adding_edges_extends_edge_attribute_vectors():
+    g = create_full_graph(4)
+
+    g.eattrs.set("name", "test")
+    g.eattrs.set("age", (5, 10, 15, 20, 25, 30))
+
+    g.add_vertices(1)
+    g.add_edges([(0, 4), (2, 4), (3, 4)])
+    assert list(g.eattrs["name"]) == ["test"] * 6 + [""] * 3
+    assert list(g.eattrs["age"]) == [5, 10, 15, 20, 25, 30] + [0] * 3
+
+
+def test_assigning_edge_attributes_between_graphs():
+    g = create_full_graph(4)
+    g.eattrs.set("age", (5, 10, 15, 20, 25, 30))
+
+    g2 = create_full_graph(4)
+    g2.eattrs["age"] = g.eattrs["age"]
+
+    assert g2.eattrs["age"] == g.eattrs["age"]
+    assert g2.eattrs["age"] is not g.eattrs["age"]
+
+    g2 = create_full_graph(8)
+    with raises(RuntimeError, match="length must be"):
+        g2.eattrs["age"] = g.eattrs["age"]
+
+
+def test_shallow_copy():
+    g = create_full_graph(4)
+
+    g.eattrs.set("name", "test")
+    g.eattrs.set("age", (5, 10, 15, 20, 25, 30))
+
+    map = g.eattrs.copy()
+    assert map["name"] == g.eattrs["name"] and map["name"] is not g.eattrs["name"]
+    assert map["age"] == g.eattrs["age"] and map["age"] is not g.eattrs["age"]
+
+
+def test_attempt_to_change_attribute_type():
+    g = create_full_graph(4)
+    g.eattrs.set("age", (5, 10, 15, 20, 25, 30))
+
+    with raises(ValueError, match="could not convert"):
+        g.eattrs["age"][2] = "test"