test_that("cdb_rbind works correctly", {
  db1 <- Compadre[1:50, ]
  db2 <- Compadre[51:100, ]
  dbm1 <- cdb_rbind(db1, db2)

  expect_s4_class(dbm1, "CompadreDB")
  expect_identical(nrow(dbm1@data), nrow(db1@data) + nrow(db2@data))
  expect_identical(ncol(dbm1@data), ncol(db1@data))

  db2@version$Version <- "X.Y.Z"
  dbm2 <- cdb_rbind(db1, db2)
  expect_true(is.na(dbm2@version$Version))
})

test_that("cdb_rbind warns and fails gracefully", {
  db1 <- Compadre[1:50, ]
  db2 <- Compadre[51:100, ]
  expect_error(cdb_rbind(db1@data, db2))

  db3 <- db2[, -30]
  expect_error(cdb_rbind(db1, db3))
})