tests/testthat/test-square_grid.R

In lawn: Client for 'Turfjs' for 'Geospatial' Analysis

context("lawn_square_grid")

a <- lawn_square_grid(c(-95, 30 ,-85, 40), 30, 'miles')
b <- lawn_square_grid(c(-95, 30 ,-85, 40), 10, 'miles')
d <- lawn_square_grid(c(-95, 30 ,-85, 40), 3, 'miles')

test_that("lawn_square_grid returns correct classes", {
  expect_is(a, "featurecollection")
  expect_is(a$type, "character")
  expect_is(a$features, "data.frame")
  expect_is(a$features$geometry$type, "character")
  expect_is(a$features$geometry$coordinates[[1]], "array")
  expect_equal(a$features$geometry$type[1], "Polygon")

  expect_is(b, "featurecollection")
  expect_is(b$features, "data.frame")

  expect_is(d, "featurecollection")
  expect_is(d$features, "data.frame")
})

test_that("cellSide parameter works as expected", {
  # expect_equal(length(a$features$geometry$coordinates), 1)
  # expect_equal(length(b$features$geometry$coordinates), 9)
  # expect_equal(length(d$features$geometry$coordinates), 64)
  expect_lt(length(a$features$geometry$coordinates),
                   length(b$features$geometry$coordinates))
  expect_lt(length(b$features$geometry$coordinates),
                   length(d$features$geometry$coordinates))
})

test_that("units parameter works as expected", {
  expect_is(lawn_square_grid(c(-95, 30 ,-85, 40), 30, 'miles'),
    "featurecollection")
  expect_is(lawn_square_grid(c(-95, 30 ,-85, 40), 30, 'kilometers'),
    "featurecollection")
})

test_that("lawn_square_grid fails correctly", {
  # missing arguments
  expect_error(lawn_square_grid(), "argument \"extent\" is missing, with no default")
  # empty featurecollection if bbox is not correct
  expect_error(lawn_square_grid(c(-95, 30 ,-85, 40), 30, 'stuff'))
  # can't pass in a character string to cellSide
  expect_error(lawn_square_grid(c(-96, 31, -84, 40), "the", 'miles'),
               "cellSide must be")
  # can't pass in a character string to cellSide
  expect_error(lawn_square_grid(c(-96, 31, -84, 40), 50, 'doesntexist'))
})