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testthat

Overview

Testing your code can be painful and tedious, but it greatly increases the quality of your code. testthat tries to make testing as fun as possible, so that you get a visceral satisfaction from writing tests. Testing should be addictive, so you do it all the time. To make that happen, testthat:

Provides functions that make it easy to describe what you expect a function to do, including catching errors, warnings, and messages.
Easily integrates in your existing workflow, whether it’s informal testing on the command line, building test suites, or using R CMD check.
Displays test progress visually, showing a pass, fail, or error for every expectation. If you’re using the terminal or a recent version of RStudio, it’ll even colour the output.

testthat draws inspiration from the xUnit family of testing packages, as well as from many of the innovative ruby testing libraries, like rspec, testy, bacon and cucumber.

testthat is the most popular unit testing package for R and is used by thousands of CRAN packages.

If you’re not familiar with testthat, the testing chapter in R packages gives a good overview, along with workflow advice and concrete examples.

Installation

# Install the released version from CRAN
install.packages("testthat")

# Or the development version from GitHub:
# install.packages("pak")
pak::pak("r-lib/testthat")

Usage

The easiest way to get started is with usethis. Assuming you’re in a package directory, just run usethis::use_test("name") to create a test file, and set up all the other infrastructure you need. If you’re using RStudio, press Cmd/Ctrl + Shift + T (or run devtools::test() if not) to run all the tests in a package.

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Version

Install

install.packages('testthat')

Monthly Downloads

429,916

Version

3.2.2

License

MIT + file LICENSE

Issues

Pull Requests

Stars

Forks

Repository

https://github.com/r-lib/testthat

Homepage

https://testthat.r-lib.org

Maintainer

Last Published

December 10th, 2024

Functions in testthat (3.2.2)

capture_condition

Capture conditions, including messages, warnings, expectations, and errors.

Multi reporter: combine several reporters in one.

Capture the state of a directory.

Test reporter: TAP format.

TeamcityReporter

Test reporter: Teamcity format.

describe: a BDD testing language

Watches code and tests for changes, rerunning tests as appropriate.

auto_test_package

Watches a package for changes, rerunning tests as appropriate.

Test reporter: summary of errors in jUnit XML format.

equality-expectations

Does code return the expected value?

Manage test reporting

Test reporter: gather all errors silently.

context_start_file

Start test context from a file name

ProgressReporter

Test reporter: interactive progress bar of errors.

RStudioReporter

Test reporter: RStudio

Capture output to console

evaluate_promise

Evaluate a promise, capturing all types of output.

expect_less_than

Deprecated numeric comparison functions

Does code return a vector with the specified length?

expect_no_error

Does code run without error, warning, message, or other condition?

Does code return NULL?

comparison-expectations

Does code return a number greater/less than the expected value?

default_reporter

Retrieve the default reporter

Test reporter: stop on error

Describe the context of a set of tests.

Does a string match a regular expression?

expect_snapshot_value

Snapshot testing for values

Tools for testing expectations

Does code return a vector with (given) names?

The building block of all expect_ functions

Determine testing status

Does an object inherit from a given class?

expect_reference

Does code return a reference to the expected object?

Does code print output to the console?

expect_equivalent

Is an object equal to the expected value, ignoring attributes?

SummaryReporter

Test reporter: summary of errors.

Compare two directory states.

expect_setequal

Does code return a vector containing the expected values?

Provide human-readable comparison of two objects

Does code throw an error, warning, message, or other condition?

expect_known_output

Expectations: is the output or the value equal to a known good value?

find_test_scripts

Find test files

Find reporter object given name or object.

expect_invisible

Does code return a visible or invisible object?

expect_snapshot

Snapshot testing

Does code execute silently?

Construct an expectation object

expect_snapshot_file

Snapshot testing for whole files

Default expectations that always succeed or fail.

local_test_context

Locally set options for maximal test reproducibility

Negate an expectation

inheritance-expectations

Does code return an object inheriting from the expected base type, S3 class, or S4 class?

is_informative_error

Is an error informative?

Old-style expectations.

expect_output_file

Expectations: is the output or the value equal to a known good value?

local_test_directory

Locally set test directory options

Temporarily change the active testthat edition

Try evaluating an expressing multiple times until it succeeds.

Use Catch for C++ Unit Testing

Quasi-labelling

reporter-accessors

Get and set active reporter.

expect_snapshot_output

Snapshot helpers

expect_cpp_tests_pass

Do C++ tests past?

Locate a file in the testing directory

Objects exported from other packages

logical-expectations

Does code return TRUE or FALSE?

snapshot_accept

Snapshot management

Source a file, directory of files, or various important subsets

takes_less_than

Does code take less than the expected amount of time to run?

testthat-package

An R package to make testing fun!

testthat_examples

Retrieve paths to built-in example test files

make_expectation

Make an equality test.

Expect that a condition holds.

local_mocked_bindings

Does code return a vector with the expected size and/or prototype?

local_snapshotter

Instantiate local snapshotting context

Run code before/after tests

Run tests in a single file

Watch a directory for changes (additions, deletions & modifications).

Mock functions in a package.

Run all tests in a package

Set maximum number of test failures allowed before aborting the run

set_state_inspector

State inspected

Superseded skip functions

Run code after all test files

Run all tests in a directory

testthat_results

Create a testthat_results object from the test results as stored in the ListReporter results field.

Generate default testing environment.

Test package examples

testthat_tolerance

Default numeric tolerance

List reporter: gather all test results along with elapsed time and file information.

LocationReporter

Test reporter: location

MinimalReporter

Test reporter: minimal.

Check reporter: 13 line summary of problems

Test reporter: fail at end.

Test reporter: start recovery.