pvolfile <- system.file("extdata", "volume.h5", package = "bioRad")
pvol <- read_pvolfile(pvolfile)
# make a pvol with two scans with identical elevation angles
pvol_duplicate_elev <- pvol
pvol_duplicate_elev$scans[[1]]$attributes$where$elangle=0.5
pvol_duplicate_elev$scans[[2]]$attributes$where$elangle=0.5

test_that("get_scan() returns error on incorrect parameters", {
  expect_error(
    get_scan("not_a_pvol", 5), "`x` must be a `pvol` object.",
    fixed = TRUE
    )
  expect_error(
    get_scan(pvol, "not_numeric"), "`elev` must be numeric.",
    fixed = TRUE
    )
  expect_error(
    get_scan(pvol, 1:2),
    regexp = "`elev` must be numeric.",
    fixed = TRUE
    )
  expect_error(
    get_scan(pvol, 1, c(T,F)),
    regexp = "all is not a flag (a length one logical vector).",
    fixed = TRUE
    )
  expect_error(
    get_scan(pvol, 1, 'a'),
    regexp = "all is not a flag (a length one logical vector).",
    fixed = TRUE
    )
})

test_that("get_scan() returns a object of class scan", {
  expect_s3_class(get_scan(pvol, 5), "scan")
})

test_that("get_scan() returns the scan closest to elev parameter", {
  # Elevation angles for example pvol are 0.5 1.5 2.5
  expect_equal(get_scan(pvol, 1.5)$geo$elangle, 1.5)
  expect_equal(get_scan(pvol, 1.9)$geo$elangle, 1.5)
  expect_equal(get_scan(pvol, 1)$geo$elangle, 0.5) # Lowest elangle is chosen if exactly in between
  expect_warning(scan <- get_scan(pvol_duplicate_elev, 1), "multiple")
  expect_equal(scan$attributes$where$elangle, 0.5)
  expect_silent(scan_list <- get_scan(pvol_duplicate_elev, 0.5, T)) # no warning if all scans are returned
  expect_type(scan_list,'list')
  expect_length(scan_list,2)
  expect_silent(scan_list <- get_scan(pvol, 0.5, T)) # no warning if all scans are returned
  expect_type(scan_list,'list')
  expect_length(scan_list,1)
  expect_equal(get_scan(pvol, 2.1)$geo$elangle, 2.5)
  expect_equal(get_scan(pvol, 40)$geo$elangle, 2.5)
})