expectation: Expectation conditions

In testthat: Unit Testing for R

Expectation conditions

Description

new_expectation() creates an expectation condition object and exp_signal() signals it. expectation() does both. is.expectation() tests if a captured condition is a testthat expectation.

These functions are primarily for internal use. If you are creating your own expectation, you do not need these functions are instead should use pass() or fail(). See vignette("custom-expectation") for more details.

Usage

expectation(type, message, ..., srcref = NULL, trace = NULL)

new_expectation(
  type,
  message,
  ...,
  srcref = NULL,
  trace = NULL,
  .subclass = NULL
)

exp_signal(exp)

is.expectation(x)

Arguments

type	Expectation type. Must be one of "success", "failure", "error", "skip", "warning".
message	Message describing test failure
...	Additional attributes for the expectation object.
srcref	Optional srcref giving location of test.
trace	An optional backtrace created by rlang::trace_back(). When supplied, the expectation is displayed with the backtrace. Expert use only.
.subclass	An optional subclass for the expectation object.
exp	An expectation object, as created by new_expectation().
x	object to test for class membership

testthat documentation built on Nov. 25, 2025, 5:09 p.m.