local_test_context {testthat}

R Documentation

Locally set options for maximal test reproducibility

Description

local_test_context() is run automatically by test_that() but you may want to run it yourself if you want to replicate test results interactively. If run inside a function, the effects are automatically reversed when the function exits; if running in the global environment, use withr::deferred_run() to undo.

local_reproducible_output() is run automatically by test_that() in the 3rd edition. You might want to call it to override the the default settings inside a test, if you want to test Unicode, coloured output, or a non-standard width.

Usage

local_test_context(.env = parent.frame())

local_reproducible_output(
  width = 80,
  crayon = FALSE,
  unicode = FALSE,
  lang = "en",
  .env = parent.frame()
)

Arguments

.env	Environment to use for scoping; expert use only.
width	Value of the "width" option.
crayon	Value of the "crayon.enabled" option.
unicode	Value of the "cli.unicode" option. The test is skipped if l10n_info()$`UTF-8` is FALSE.
lang	Optionally, supply a BCP47 language code to set the language used for translating error messages. This is a lower case two letter ISO 639 country code, optionally followed by "_" or "-" and an upper case two letter ISO 3166 region code.

Details

local_test_context() sets TESTTHAT = "true", which ensures that is_testing() returns TRUE and allows code to tell if it is run by testthat.

In the third edition, local_test_context() also calls local_reproducible_output() which temporary sets the following options:

• cli.dynamic = FALSE so that tests assume that they are not run in a dynamic console (i.e. one where you can move the cursor around).

• cli.unicode (default: FALSE) so that the cli package never generates unicode output (normally cli uses unicode on Linux/Mac but not Windows). Windows can't easily save unicode output to disk, so it must be set to false for consistency.

• cli.condition_width = Inf so that new lines introduced while width-wrapping condition messages don't interfere with message matching.

• crayon.enabled (default: FALSE) suppresses ANSI colours generated by the crayon package (normally colours are used if crayon detects that you're in a terminal that supports colour).

• cli.num_colors (default: 1L) Same as the crayon option.

• lifecycle_verbosity = "warning" so that every lifecycle problem always generates a warning (otherwise deprecated functions don't generate a warning every time).

• max.print = 99999 so the same number of values are printed.

• OutDec = "." so numbers always uses . as the decimal point (European users sometimes set OutDec = ",").

• rlang_interactive = FALSE so that rlang::is_interactive() returns FALSE, and code that uses it pretends you're in a non-interactive environment.

• useFancyQuotes = FALSE so base R functions always use regular (straight) quotes (otherwise the default is locale dependent, see sQuote() for details).

• width (default: 80) to control the width of printed output (usually this varies with the size of your console).

And modifies the following env vars:

• Unsets RSTUDIO, which ensures that RStudio is never detected as running.

• Sets LANGUAGE = "en", which ensures that no message translation occurs.

Finally, it sets the collation locale to "C", which ensures that character sorting the same regardless of system locale.

Examples

Run examples

local({
  local_test_context()
  cat(crayon::blue("Text will not be colored"))
  cat(cli::symbol$ellipsis)
  cat("\n")
})
test_that("test ellipsis", {
  local_reproducible_output(unicode = FALSE)
  expect_equal(cli::symbol$ellipsis, "...")

  local_reproducible_output(unicode = TRUE)
  expect_equal(cli::symbol$ellipsis, "\u2026")
})

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