test_that("missing-value markers become NA, not zero", {
  f <- tempfile(fileext = ".out")
  writeLines(c("ApsimVersion = 7.10 r4177", "Title = T1",
               "           Date           wrr          stage",
               "  (dd/mmm/yyyy)       (kg/ha)             ()",
               "    01/Jun/2016           0.0              ?",
               "    02/Jun/2016         100.5            2.0"), f)
  d <- read_out(f)
  expect_true(is.na(d$stage[1]))
  expect_equal(d$wrr[2], 100.5)
  expect_s3_class(d$Date, "Date")
  expect_equal(attr(d, "units")[["wrr"]], "kg/ha")
  expect_equal(d$sim[1], "T1")
})

test_that("column names containing parentheses do not break unit detection", {
  f <- tempfile(fileext = ".out")
  writeLines(c("Title = T2",
               "           Date  flow_water(1)  flow_water(2)",
               "  (dd/mmm/yyyy)           (mm)           (mm)",
               "    01/Jun/2016          1.000          2.000"), f)
  d <- read_out(f)
  expect_true(all(c("flow_water(1)", "flow_water(2)") %in% names(d)))
  expect_equal(d$`flow_water(2)`[1], 2)
})