tests/testthat/charr/common/test-fixed-empty-backend.R

In charr: String Processing Reimagined for 'ALTREP' Strings

# charr-owned file: zero-recycling returns for Reader-backed fixed search.

fixed_bytes <- function() {
  value <- rawToChar(as.raw(c(0xff, 0xfe)))
  Encoding(value) <- "bytes"
  value
}


test_that("fixed operations return exact empty shapes before acquisition", {
  bytes <- fixed_bytes()

  expect_identical(
    charr_test_leaf("ci_detect_fixed")(bytes, character()),
    logical()
  )
  expect_identical(
    charr_test_leaf("ci_count_fixed")(character(), "a"),
    integer()
  )
  expect_identical(
    charr_test_leaf("ci_startswith_fixed")(bytes, "a", from = integer()),
    logical()
  )
  expect_identical(
    charr_test_leaf("ci_endswith_fixed")(bytes, character()),
    logical()
  )

  expect_identical(
    charr_test_leaf("ci_locate_first_fixed")(bytes, character()),
    cbind(start = integer(), end = integer())
  )
  expect_identical(
    charr_test_leaf("ci_locate_first_fixed")(
      bytes, character(), get_length = TRUE
    ),
    cbind(start = integer(), length = integer())
  )
  expect_identical(
    charr_test_leaf("ci_locate_all_fixed")(bytes, character()),
    list()
  )

  extracted <- charr_test_leaf("ci_extract_first_fixed")(bytes, character())
  expect_identical(extracted, character())
  expect_identical(is_charr_result(extracted), charr_altrep())
  expect_identical(
    charr_test_leaf("ci_extract_all_fixed")(bytes, character()),
    list()
  )
  expect_identical(
    charr_test_leaf("ci_extract_all_fixed")(bytes, character(), simplify = TRUE),
    matrix(character(), 0L, 0L)
  )

  replaced <- charr_test_leaf("ci_replace_all_fixed")(bytes, "a", character())
  expect_identical(replaced, character())
  expect_identical(is_charr_result(replaced), charr_altrep())

  expect_identical(
    charr_test_leaf("ci_split_fixed")(bytes, "_", n = integer()),
    list()
  )
  expect_identical(
    charr_test_leaf("ci_split_fixed")(
      bytes, character(), simplify = NA
    ),
    matrix(character(), 0L, 0L)
  )
})


test_that("fixed zero recycling skips large Reader-backed subjects", {
  strings <- charr_test_leaf("ci_trim_both")(rep(c("café", "🙂x", "ü"), 2000L))
  expect_identical(charport::is_charvec(strings), charr_altrep())

  expect_identical(charr_test_leaf("ci_detect_fixed")(strings, character()), logical())
  expect_identical(
    charr_test_leaf("ci_locate_all_fixed")(strings, character()),
    list()
  )
  expect_identical(
    charr_test_leaf("ci_extract_first_fixed")(strings, character()),
    character()
  )
  expect_identical(
    charr_test_leaf("ci_split_fixed")(strings, character()),
    list()
  )
})