data.table (version 1.16.4)

test: Test assertions for equality, exceptions and console output

Description

An internal testing function used in data.table test scripts that are run by test.data.table.

Usage

test(num, x, y = TRUE,
     error = NULL, warning = NULL, message = NULL,
     output = NULL, notOutput = NULL, ignore.warning = NULL,
     options = NULL, env = NULL)

Value

Logical TRUE when test passes, FALSE when test fails. Invisibly.

Arguments

num

A unique identifier for a test, helpful in identifying the source of failure when testing is not working. Currently, we use a manually-incremented system with tests formatted as n.m, where essentially n indexes an issue and m indexes aspects of that issue. For the most part, your new PR should only have one value of n (scroll to the end of inst/tests/tests.Rraw to see the next available ID) and then index the tests within your PR by increasing m. Note -- n.m is interpreted as a number, so 123.4 and 123.40 are actually the same -- please 0-pad as appropriate. Test identifiers are checked to be in increasing order at runtime to prevent duplicates being possible.

x

An input expression to be evaluated.

y

Pre-defined value to compare to x, by default TRUE.

error

When you are testing behaviour of code that you expect to fail with an error, supply the expected error message to this argument. It is interpreted as a regular expression, so you can be abbreviated, but try to include the key portion of the error so as not to accidentally include a different error message.

warning

Same as error, in the case that you expect your code to issue a warning. Note that since the code evaluates successfully, you should still supply y.

message

Same as warning but expects message exception.

output

If you are testing the printing/console output behaviour; e.g. with verbose=TRUE or options(datatable.verbose=TRUE). Again, regex-compatible and case sensitive.

notOutput

Or if you are testing that a feature does not print particular console output. Case insensitive (unlike output) so that the test does not incorrectly pass just because the string is not found due to case.

ignore.warning

A single character string. Any warnings emitted by x that contain this string are dropped. Remaining warnings are compared to the expected warning as normal.

options

A named list of options to set for the duration of the test. Any code evaluated during this call to `test()` (usually, `x`, or maybe `y`) will run with the named options set, and the original options will be restored on return. This is a named list since different options can have different types in general, but in typical usage, only one option is set at a time, in which case a named vector is also accepted.

env

A named list of environment variables to set for the duration of the test, much like options. A list entry set to NULL will unset (i.e., Sys.unsetenv) the corresponding variable.

See Also

test.data.table

Examples

test = data.table:::test
test(1, x = sum(1:5), y = 15L)
test(2, log(-1), NaN, warning="NaNs")
test(3, sum("a"), error="invalid.*character")
# test failure example
stopifnot(
  test(4, TRUE, FALSE) == FALSE
)
# NA_real_ vs NaN
test(5.01, NA_real_, NaN)
test(5.03, all.equal(NaN, NA_real_))
test(5.02, identical(NaN, NA_real_), FALSE)