tests/testthat/test-rectify.R

In ropensci/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))
})