add test for spider

tests/backend/test_tensor.py

@@ -6,6 +6,9 @@
 import lambeq.backend.grammar as grammar
 from lambeq.backend.tensor import *
 
+@pytest.fixture
+def spider():
+    return Spider(Dim(3), 5, 3)
 
 def test_Ty():
     assert Dim(1,1,1,1,1) == Dim(1) == Dim()
@@ -85,3 +88,22 @@ def test_lambdify():
 
     assert bx1.lambdify(a,b,c,d)(1,2,3,4) == bx1_concrete
     assert (bx1 >> bx2).lambdify(a,b,c,d)(1,2,3,4) == bx1_concrete >> bx2_concrete
+
+def test_to_tn_spider_unfuse(spider):
+    nodes, edges = spider.to_tn()
+
+    assert len(edges) == spider.n_legs_in + spider.n_legs_out
+    assert all(node.rank <= 3 for node in nodes)
+
+def test_spider_eval(spider):
+    n_legs = 8
+    dim = 3
+
+    expected = np.zeros(tuple(dim for _ in range(n_legs)))
+    for i in range(dim):
+        expected[tuple(i for _ in range(n_legs))] = 1
+
+    result = spider.eval()
+
+    assert result.shape == tuple(dim for _ in range(n_legs))
+    assert np.allclose(result, expected)