tests/testthat/test-fromJSON-dataframe.R

In jsonlite: A Simple and Robust JSON Parser and Generator for R

options(stringsAsFactors = FALSE)

test_that("recover nested data frames", {
  x1 <- x2 <- x3 <- x4 <- x5 <- x6 <- data.frame(foo = c(1:2))
  x2$bar <- c("jeroen", "eli")
  x3$bar <- x4$bar <- x5$bar <- x6$bar <- data.frame(name = c("jeroen", "eli"))
  x4$bar$age <- x5$bar$age <- c(28, 24)
  x6$bar$age <- c(28, NA)
  x5$bar$food <- data.frame(yum = c("Rice", "Pasta"))
  x6$bar$food <- data.frame(yum = c(NA, "Pasta"))

  #add to list
  objects <- list(x1, x2, x3, x4, x5, x6)

  #test all but list
  lapply(objects, function(object) {
    expect_equal(fromJSON(toJSON(object)), object)
    expect_equal(fromJSON(toJSON(object, na = "null")), object)
    expect_equal(names(fromJSON(toJSON(object), flatten = TRUE)), names(unlist(object[1, , drop = FALSE])))
  })

  #test all in list
  expect_equal(fromJSON(toJSON(objects)), objects)
})

test_that("recover lists in data frames", {
  x <- data.frame(author = c("Homer", "Virgil", "Jeroen"))
  x$poems = list(c("Iliad", "Odyssey"), c("Eclogues", "Georgics", "Aeneid"), character())

  y <- data.frame(author = c("Homer", "Virgil", "Jeroen"))
  y$poems = list(
    data.frame(title = c("Iliad", "Odyssey"), year = c(-1194, -800)),
    data.frame(title = c("Eclogues", "Georgics", "Aeneid"), year = c(-44, -29, -19)),
    data.frame()
  )

  z <- list(x = x, y = y)
  zz <- list(x, y)

  expect_equal(fromJSON(toJSON(x)), x)
  expect_equal(fromJSON(toJSON(y)), y)
  expect_equal(fromJSON(toJSON(z)), z)
  expect_equal(fromJSON(toJSON(zz)), zz)
})

#note: nested matrix does not perfectly restore
test_that("nested matrix in data frame", {
  x <- data.frame(foo = 1:2)
  x$bar <- matrix(c(1:5, NA), 2)

  expect_true(validate(toJSON(x)))

  y <- fromJSON(toJSON(x))
  expect_s3_class(y, "data.frame")
  expect_equal(names(x), names(y))
  expect_equal(length(y[[1, "bar"]]), 3)
})