tests/testthat/test-tar-terra-tiles.R

In geotargets: 'targets' Extensions for Geographic Spatial Formats

# test_that() #Included to make RStudio recognize this file as a test # nolint
targets::tar_test("tar_terra_tiles() works", {
  targets::tar_script({
    library(targets)
    library(geotargets)
    library(terra)
    list(
      tar_target(
        my_file,
        system.file("ex/logo.tif", package = "terra"),
        format = "file"
      ),
      tar_terra_rast(
        my_map,
        terra::rast(my_file)
      ),
      tar_terra_tiles(
        name = rast_split,
        raster = my_map,
        tile_fun = tile_blocksize
      ),
      tar_terra_tiles(
        name = rast_split_grid,
        raster = my_map,
        tile_fun = \(x) tile_grid(x, ncol = 2, nrow = 2)
      ),
      tar_terra_tiles(
        name = rast_split_n,
        raster = my_map,
        tile_fun = \(x) tile_n(x, n = 6)
      )
    )
  })
  manifest <- targets::tar_manifest()
  # check that the command is correct
  expect_identical(
    manifest[manifest$name == "rast_split_exts", ][["command"]],
    "tile_blocksize(my_map)"
  )
  # expect_equal(manifest[manifest$name == "rast_split_n_exts", ][["command"]],
  #              "tile_grid(my_map, ncol = 2, nrow = 2)")
  #TODO: haven't figured out how to make manifest look nice with anon funs yet
  expect_identical(
    manifest[manifest$name == "rast_split", ][["command"]],
    "set_window(my_map, terra::ext(rast_split_exts))"
  )
  targets::tar_make(reporter = "silent")
  expect_true(all(is.na(targets::tar_meta()$error)))
})

targets::tar_test("recombined tiles are equal to original", {
  targets::tar_script({
    library(targets)
    library(geotargets)
    library(terra)
    list(
      tar_target(
        my_file,
        system.file("ex/elev.tif", package = "terra"),
        format = "file"
      ),
      tar_terra_rast(
        my_map,
        # create multi-layer raster for testing
        rast(c(my_file, my_file))
      ),
      tar_terra_tiles(
        name = rast_split_blocksize,
        raster = my_map,
        tile_fun = tile_blocksize
      ),
      tar_terra_tiles(
        name = rast_split_grid,
        raster = my_map,
        tile_fun = \(x) tile_grid(x, ncol = 2, nrow = 2),
        description = "Split into 4 tiles in a 2x2 grid"
      ),
      tar_terra_tiles(
        name = rast_split_n,
        raster = my_map,
        tile_fun = \(x) tile_n(x, n = 6),
        description = "Split into 6 tiles"
      )
    )
  })
  targets::tar_make(reporter = "silent")
  targets::tar_load(
    c(
      my_map,
      rast_split_blocksize,
      rast_split_grid,
      rast_split_n
    )
  )
  recombined_blocksize <- terra::merge(terra::sprc(rast_split_blocksize))
  recombined_grid <- terra::merge(terra::sprc(rast_split_grid))
  recombined_n <- terra::merge(terra::sprc(rast_split_n))
  expect_identical(terra::values(my_map), terra::values(recombined_blocksize))
  expect_identical(terra::values(my_map), terra::values(recombined_grid))
  expect_identical(terra::values(my_map), terra::values(recombined_n))
})