Add tests

test/Transformations_test.jl

@@ -254,4 +254,33 @@
             @test contract(A, contract(B, C, dims = [])) ≈ contract(A_2, contract(B_2, C_2, dims = []))
         end
     end
+
+    @testset "SplitSimplification" begin
+        using Tenet: SplitSimplification
+
+        v1 = Tensor([1, 2, 3], (:i,))
+        v2 = Tensor([4, 5, 6], (:j, ))
+        m1 = Tensor(rand(3, 3), (:k, :l))
+
+        t1 = contract(v1, v2)
+        tensor = contract(t1, m1) # Define a tensor which can be splitted in three
+
+        tn = TensorNetwork([tensor, Tensor(rand(3, 3, 3), (:k, :m, :n)), Tensor(rand(3, 3, 3), (:l, :n, :o))])
+        reduced = transform(tn, SplitSimplification)
+
+        # Test that the new tensors in reduced are smaller than the deleted ones
+        deleted_tensors = filter(t -> labels(t) ∉ labels.(tensors(reduced)), tensors(tn))
+        new_tensors = filter(t -> labels(t) ∉ labels.(tensors(tn)), tensors(reduced))
+
+        smallest_deleted = minimum(prod ∘ size, deleted_tensors)
+        largest_new = maximum(prod ∘ size, new_tensors)
+
+        @test smallest_deleted > largest_new
+
+        # Test that the resulting contraction is the same as the original
+        # TODO: Change for: @test contract(reduced) ≈ contract(tn), when is fixed
+        A_2, B_2, C_2, D_2, E_2 = tensors(reduced)
+        c_reduced = contract(contract(contract(contract(A_2, B_2), C_2), D_2), E_2)
+        @test contract(contract(tensors(tn)[1], tensors(tn)[2]), tensors(tn)[3]) ≈ c_reduced
+    end
 end