tests/testthat/test_dplyr.R

In mlr3db: Data Base Backend for 'mlr3'

skip_if_not_installed("dplyr")
skip_if_not_installed("dbplyr")

test_that("valid DataBackend (tbl/tibble)", {
  data = iris
  data$Petal.Length[91:120] = NA
  data = as_tbl(data)
  b = DataBackendDplyr$new(data, "row_id")
  expect_backend(b)
  expect_iris_backend(b, n_missing = 30L)
})

test_that("valid DataBackend (tbl/sqlite)", {
  skip_if_not_installed("RSQLite")
  data = iris
  data$Petal.Length[91:120] = NA
  data = as_sqlite_tbl(data)
  b = DataBackendDplyr$new(data, "row_id")
  expect_backend(b)
  expect_iris_backend(b, n_missing = 30L)
})

test_that("valid DataBackend (as_sqlite_backend)", {
  skip_if_not_installed("RSQLite")
  data = iris
  data$Petal.Length[91:120] = NA
  b = as_sqlite_backend(data)
  expect_backend(b)
  expect_iris_backend(b, n_missing = 30L)
})

test_that("strings_as_factors", {
  skip_if_not_installed("RSQLite")

  data = iris

  tbl = as_sqlite_tbl(data)
  b = DataBackendDplyr$new(data = tbl, "row_id", strings_as_factors = FALSE)
  expect_character(b$head()$Species, any.missing = FALSE)
  expect_character(b$data(b$rownames[1], "Species")$Species, any.missing = FALSE)

  tbl = as_sqlite_tbl(data)
  b = DataBackendDplyr$new(data = tbl, "row_id", strings_as_factors = TRUE)
  expect_factor(b$head()$Species, any.missing = FALSE)
  expect_factor(b$data(b$rownames[1], "Species")$Species, any.missing = FALSE)

  tbl = as_sqlite_tbl(data)
  b = DataBackendDplyr$new(data = tbl, "row_id", strings_as_factors = "Species")
  expect_factor(b$head()$Species, any.missing = FALSE)
  expect_factor(b$data(b$rownames[1], "Species")$Species, any.missing = FALSE)

  expect_error(DataBackendDplyr$new(data = tbl, "row_id", strings_as_factors = "Sepal.Length"))
})

test_that("as_data_backend", {
  skip_if_not_installed("tibble")
  data = iris
  data$row_id = 1:150
  data = tibble::as_tibble(data)
  expect_r6(as_data_backend(data, primary_key = "row_id"), "DataBackendDataTable")

  data = as_sqlite_tbl(data = data, primary_key = "row_id")
  b = as_data_backend(data, primary_key = "row_id")
  expect_r6(b, "DataBackendDplyr")
})

test_that("distinct with NULL rows", {
  b = as_sqlite_backend(iris)
  expect_equal(
    b$distinct(NULL, b$colnames),
    b$distinct(b$rownames, b$colnames)
  )
})

test_that("show_query", {
  b = as_sqlite_backend(iris)
  expect_output(dplyr::show_query(b), "SELECT *")
})