tests/testthat/test-write_fs_patch.R

In freesurferformats: Read and Write 'FreeSurfer' Neuroimaging File Formats

test_that("A tiny patch can be written to binary patch format and re-read", {
  # create a patch
  num_vertices <- 6L # a tiny patch
  vertices <- matrix(rep(0., num_vertices * 5), ncol = 5)
  vertices[, 1] <- seq.int(num_vertices) # 1-based vertex indices
  vertices[, 2:4] <- matrix(rnorm(num_vertices * 3, 8, 2), ncol = 3) # vertex coords
  vertices[, 5] <- rep(0L, num_vertices) # is_border
  vertices[3, 5] <- 1L # set a vertex to be a border vertex
  patch <- fs.patch(vertices)

  patch_file <- tempfile(fileext = ".patch")
  write.fs.patch(patch_file, patch)

  same_patch <- read.fs.patch(patch_file)
  expect_equal(nrow(patch$vertices), nrow(same_patch$vertices))
})


test_that("Creating a patch from invalid data leads to errors", {
  num_vertices <- 6L
  vertices <- matrix(rep(0., num_vertices * 5), ncol = 5) # okay
  vertices_broken <- matrix(rep(0., num_vertices * 5), ncol = 6) # note ncol = 6, which is invalid
  expect_error(fs.patch(vertices_broken))
  expect_error(fs.patch(vertices, faces = vertices_broken)) # faces must have 5 cols
})