tests/testthat/test-run-qgis.R

In jannes-m/RQGIS3: Integrating R with QGIS3

library("sp")
library("sf")
library("raster")

context("run_qgis")

# Check QGIS-----------------------------------------------

test_that("Test, if QGIS-algorithms are working?", {
  testthat::skip_on_cran()

  coords_1 = matrix(
    data = c(0, 0, 1, 0, 1, 1, 0, 1, 0, 0),
    ncol = 2, byrow = TRUE
  )
  coords_2 = coords_1 + 2
  # convert the coordinates into polygons
  polys = list(
    Polygons(list(Polygon(coords_1)), 1),
    Polygons(list(Polygon(coords_2)), 2)
  )
  polys = as(SpatialPolygons(polys), "SpatialPolygonsDataFrame")

  # Retrieve the function arguments in such a way that they can be easily
  # specified and serve as input for run_qgis
  alg = "native:centroids"
  # finally, let QGIS do the work!!
  vec_1 = run_qgis(
    alg,
    INPUT = polys,
    OUTPUT = file.path(tempdir(), "coords.shp"),
    show_output_paths = FALSE,
    # let's load the QGIS output directly into R!
    load_output = TRUE
  )

  # check if the output is an spatial object
  expect_is(vec_1, "sf")
  # now use ...-notation and sf as input
  vec_2 = run_qgis(
    alg = "native:centroids",
    INPUT = st_as_sf(polys),
    OUTPUT = file.path(tempdir(), "coords.shp"),
    show_output_paths = FALSE, load_output = TRUE
  )
  # check if the output is spatial object
  expect_is(vec_2, "sf")

  # check geojson and gpkg
  vec_3 = run_qgis(
    alg,
    INPUT = polys,
    OUTPUT = file.path(tempdir(), "coords.geojson"),
    show_output_paths = FALSE,
    # let's load the QGIS output directly into R!
    load_output = TRUE
  )
  expect_is(vec_3, "sf")

  vec_4 = run_qgis(
    alg,
    INPUT = polys,
    OUTPUT = file.path(tempdir(), "coords.gpkg"),
    show_output_paths = FALSE,
    # let's load the QGIS output directly into R!
    load_output = TRUE
  )
  expect_is(vec_4, "sf")
})

# Check SAGA ----------------------------------------------

test_that("Test, if SAGA-algorithms are working?", {
  testthat::skip_on_appveyor()
  testthat::skip_on_cran()

  # attach data
  data("dem")
  params = get_args_man(alg = "saga:sagawetnessindex", options = TRUE)
  params$DEM = dem
  params$AREA = file.path(tempdir(), "area.sdat")
  params$SLOPE = file.path(tempdir(), "slope.sdat")
  params$AREA_MOD = file.path(tempdir(), "area_mod.sdat")
  params$TWI = file.path(tempdir(), "twi.sdat")
  saga_out_1 = run_qgis(
    "saga:sagawetnessindex",
    params = params,
    show_output_paths = FALSE, load_output = TRUE
  )
  # check if the output is a raster
  expect_is(stack(saga_out_1), "RasterStack")
  # now use ...-notation
  saga_out_2 = run_qgis(
    "saga:sagawetnessindex",
    DEM = dem,
    AREA = file.path(tempdir(), "area.sdat"),
    SLOPE = file.path(tempdir(), "slope.sdat"),
    AREA_MOD = file.path(tempdir(), "area_mod.sdat"),
    TWI = file.path(tempdir(), "twi.sdat"),
    show_output_paths = FALSE, load_output = TRUE
  )
  # check if the output is a raster
  expect_is(stack(saga_out_2), "RasterStack")
})


# Check GRASS 7------------------------------------------------------

test_that("Test, if GRASS7-algorithms are working?", {
  testthat::skip_on_cran()

  # attach data
  data("dem")
  params = get_args_man(alg = "grass7:r.slope.aspect", options = TRUE)
  params$elevation = dem
  params$slope = file.path(tempdir(), "slope.tif")
  params$aspect = file.path(tempdir(), "aspect.tif")
  grass_out_1 = run_qgis(
    "grass7:r.slope.aspect",
    params = params,
    show_output_paths = FALSE, load_output = TRUE
  )
  # check if the output is a raster
  expect_is(grass_out_1[[1]], "RasterLayer")
  expect_is(grass_out_1[[2]], "RasterLayer")

  # now use ...-notation
  grass_out_2 = run_qgis(
    "grass7:r.slope.aspect",
    elevation = dem,
    slope = file.path(tempdir(), "slope.tif"),
    show_output_paths = FALSE, load_output = TRUE
  )
  # check if the output is a raster
  expect_is(grass_out_2, "RasterLayer")
})

# multipleparameter input----------------------------------

test_that("Test, if multipleparameter input works?", {
  testthat::skip_on_cran()

  # attach data
  data("random_points")
  pt_1 = random_points[1:10, ]
  pt_2 = random_points[91:100, ]
  alg = "native:mergevectorlayers"
  params = get_args_man(alg = alg)
  params$LAYERS = list(pt_1, pt_2)
  params$OUTPUT = file.path(tempdir(), "out.shp")
  out = run_qgis(
    alg = alg, params = params, load_output = TRUE,
    show_output_paths = FALSE
  )
  # test if the two shps were joined, i.e., now have 20 rows
  expect_equal(nrow(out), 20)

  # check if it works using a list containing file names
  file_1 = file.path(tempdir(), "file1.shp")
  file_2 = file.path(tempdir(), "file2.shp")
  write_sf(pt_1, file_1)
  write_sf(pt_2, file_2)
  params$LAYERS = list(file_1, file_2)
  out_2 = run_qgis(
    alg = alg, params = params, load_output = TRUE,
    show_output_paths = FALSE
  )
  expect_equal(nrow(out_2), 20)
})