tests/testthat/test-rectify.R

In mapscanner: Print Maps, Draw on Them, Scan Them Back in

context("rectify")

test_that ("errors", {
               expect_error (ms_rectify_map (),
                             'argument "map_original" is missing, with no default')
               expect_error (ms_rectify_map (map_original = "junk.pdf"),
                             "Neither junk.pdf nor junk.png exist")
               f_orig <- system.file ("extdata", "omaha.png",
                                      package = "mapscanner")
               f_modified <- system.file ("extdata", "omaha-polygons.png",
                                          package = "mapscanner")
               expect_error (ms_rectify_map (f_orig, f_modified,
                                             non_linear = FALSE),
                             "non_linear must be a single integer value")
               expect_error (ms_rectify_map (f_orig, f_modified,
                                             non_linear = 4),
                             "non_linear must be a value of 0, 1, or 2")
               expect_error (ms_rectify_map (f_orig, f_modified,
                                             length_threshold = "a"),
                             "length_threshold must be numeric")

})

test_that("rectify", {
              f_orig <- system.file ("extdata", "omaha.png",
                                     package = "mapscanner")
              expect_true (file.exists (f_orig))
              expect_true (is_png (f_orig))
              f_modified <- system.file ("extdata", "omaha-polygons.png",
                                         package = "mapscanner")
              expect_true (file.exists (f_modified))
              expect_true (is_png (f_modified))

              # have to down-scale images for testing because RNiftyReg takes
              # way too long
              f_orig2 <- file.path (tempdir (), "omaha.png")
              f_modified2 <- file.path (tempdir (), "omaha-polygons.png")
              magick::image_read (f_orig) %>%
                  magick::image_resize ("25%") %>%
                  magick::image_write (f_orig2)
              magick::image_read (f_modified) %>%
                  magick::image_resize ("25%") %>%
                  magick::image_write (f_modified2)

              skip_on_cran ()

              # ------- polygons
              expect_silent (res_p <- ms_rectify_map (f_orig2, f_modified2,
                                                      type = "polygons",
                                                      quiet = TRUE))
              expect_is (res_p, "sf")
              expect_is (res_p$geometry, "sfc_POLYGON")
              expect_message (res_p2 <- ms_rectify_map (f_orig2, f_modified2,
                                                        type = "polygons"))
              expect_identical (res_p, res_p2)

              # ------- points
              expect_silent (res_1 <- ms_rectify_map (f_orig2, f_modified2,
                                                      type = "points",
                                                      quiet = TRUE))
              expect_is (res_1, "sf")
              expect_is (res_1$geometry, "sfc_POINT")

              # ------- hulls

              expect_message (res_h <- ms_rectify_map (f_orig2, f_modified2,
                                                       downsample = 11,
                                                       type = "hulls",
                                                       quiet = TRUE),
                              "downsample is only used for polygons")
              expect_is (res_h, "sf")
              expect_is (res_h$geometry, "sfc_POLYGON")
              expect_true (all (sf::st_area (res_h) > sf::st_area (res_p)))

              expect_error (ms_rectify_map (f_orig2, f_modified2,
                                            concavity = "a",
                                            type = "hulls",
                                            quiet = TRUE),
                            "concavity must be numeric")
              expect_message (res_h2 <- ms_rectify_map (f_orig2, f_modified2,
                                                        concavity = 2,
                                                        type = "hulls",
                                                        quiet = TRUE),
                              paste0 ("concavity must be between 0 and 1; ",
                                      "setting to default of 0"))
              expect_identical (res_h, res_h2)
              expect_message (res_h2 <- ms_rectify_map (f_orig2, f_modified2,
                                                        length_threshold = 0,
                                                        type = "hulls",
                                                        quiet = TRUE),
                              "length_threshold must be >= 1")
              expect_identical (res_h, res_h2)
              expect_silent (res_h2 <- ms_rectify_map (f_orig2, f_modified2,
                                                       concavity = 1,
                                                       type = "hulls",
                                                       quiet = TRUE))
              a1 <- sf::st_area (res_h)
              a2 <- sf::st_area (res_h2)
              expect_true (all (a2 < a1))
})