test_that("Weighted indexing does not remove edges", {
  g <- make_ring(10)
  g[1, 2, attr = "weight"] <- 0
  expect_true("weight" %in% edge_attr_names(g))
  expect_that(E(g)$weight, equals(c(0, rep(NA, 9))))

  el <- as_edgelist(g)
  g[from = el[, 1], to = el[, 2], attr = "sim"] <- rep(0:1, length.out = ecount(g))
  expect_true("sim" %in% edge_attr_names(g))
  expect_that(E(g)$sim, equals(rep(0:1, 5)))

  V(g)$name <- letters[seq_len(vcount(g))]
  el <- as_edgelist(g)
  g[from = el[, 1], to = el[, 2], attr = "sim"] <- rep(1:0, length.out = ecount(g))
  expect_that(E(g)$sim, equals(rep(1:0, 5)))
})