tests/testthat/test-data-formats.R

In Rsagacmd: Linking R with the Open-Source 'SAGA-GIS' Software

test_that("test raster formats (SAGA)", {
  testthat::skip_on_cran()
  testthat::skip_if(is.null(search_saga()))

  saga <- saga_gis(raster_format = "SAGA")
  dem <- saga$grid_calculus$random_terrain()

  # incorrect output format
  testthat::expect_error(
    saga$ta_morphometry$terrain_ruggedness_index_tri(
      dem,
      tri = tempfile(fileext = ".tif")
    )
  )

  # partially incorrect format; SAGA-GIS expects to read/write grid files using
  # the 'sgrd' file extension, but raster/terra have to read/write using the
  # 'sdat' extension. Rsagacmd enforces using 'sgrd' for consistency.
  testthat::expect_error(
    saga$ta_morphometry$terrain_ruggedness_index_tri(
      dem,
      tri = tempfile(fileext = ".sdat")
    )
  )

  # correct output format
  result <- saga$ta_morphometry$terrain_ruggedness_index_tri(
    dem,
    tri = tempfile(fileext = ".sgrd")
  )
})


test_that("test raster formats (SAGA Compressed)", {
  testthat::skip_on_cran()
  testthat::skip_if(is.null(search_saga()))
  testthat::skip_if(saga_version(search_saga()) < numeric_version("5.0"))

  saga <- saga_gis(raster_format = "SAGA Compressed")
  dem <- saga$grid_calculus$random_terrain()

  # incorrect output format
  testthat::expect_error(
    saga$ta_morphometry$terrain_ruggedness_index_tri(
      dem,
      tri = tempfile(fileext = ".tif")
    )
  )

  # correct output format
  result <- saga$ta_morphometry$terrain_ruggedness_index_tri(
    dem,
    tri = tempfile(fileext = ".sg-grd-z")
  )
})


test_that("test vector formats (GeoPackage)", {
  testthat::skip_on_cran()
  testthat::skip_if(is.null(search_saga()))
  testthat::skip_if(saga_version(search_saga()) < numeric_version("5.0"))

  saga <- saga_gis(vector_format = "GeoPackage")

  nc <- sf::st_read(system.file("shape/nc.shp", package = "sf"), quiet = TRUE)

  # incorrect output format
  testthat::expect_error(
    saga$shapes_polygons$polygon_properties(
      nc,
      output = tempfile(fileext = ".shp")
    )
  )

  # correct output format
  result <- saga$shapes_polygons$polygon_properties(
    polygons = nc,
    output = tempfile(fileext = ".gpkg")
  )
})