tests/testthat/test-read_helpers.R

In wal: Read and Write 'wal' Bitmap Image Files and Other 'Quake' Assets

# Tests for the internal read.c.string helper that reads fixed-size, NUL-padded
# C strings from the Quake file formats without triggering the
# "truncating string with embedded nuls" warning.


testthat::test_that("read.c.string returns the string up to the first NUL byte.", {
  # 12-byte field: 'abc' + 9 NUL bytes, followed by 'xyz'.
  raw_data = c(charToRaw("abc"), rep(as.raw(0), 9L), charToRaw("xyz"));
  con = rawConnection(raw_data, open = "rb");
  on.exit(close(con));

  s = wal:::read.c.string(con, 12L);
  testthat::expect_identical(s, "abc");
})


testthat::test_that("read.c.string advances the connection by the full field size.", {
  # 12-byte field: 'abc' + 9 NUL bytes, followed by 'xyz'.
  raw_data = c(charToRaw("abc"), rep(as.raw(0), 9L), charToRaw("xyz"));
  con = rawConnection(raw_data, open = "rb");
  on.exit(close(con));

  wal:::read.c.string(con, 12L);
  rest = readBin(con, "raw", n = 3L);
  testthat::expect_identical(rest, charToRaw("xyz")); # 'xyz' follows the 12-byte field.
})


testthat::test_that("read.c.string returns an empty string for an all-NUL field.", {
  con = rawConnection(rep(as.raw(0), 8L), open = "rb");
  on.exit(close(con));

  s = wal:::read.c.string(con, 8L);
  testthat::expect_identical(s, "");
})


testthat::test_that("read.c.string returns the full string when the field has no NUL byte.", {
  con = rawConnection(charToRaw("PACK"), open = "rb");
  on.exit(close(con));

  s = wal:::read.c.string(con, 4L);
  testthat::expect_identical(s, "PACK");
})


testthat::test_that("read.wal reads the header name fields correctly.", {
  walf = system.file("extdata", "bricks.wal", package = "wal", mustWork = TRUE);

  wal = wal::read.wal(walf);
  testthat::expect_identical(wal$header$tex_name, "e1u1/black");
  testthat::expect_identical(wal$header$anim_name, "");
})