A test encapsulates a series of expectations about small, self-contained set of functionality. Each test is contained in a context and contains multiple expectations.

test_that(desc, code)

Arguments

desc

test name. Names should be kept as brief as possible, as they are often used as line prefixes.

code

test code containing expectations

Details

Tests are evaluated in their own environments, and should not affect global state.

When run from the command line, tests return NULL if all expectations are met, otherwise it raises an error.

Examples

test_that("trigonometric functions match identities", { expect_equal(sin(pi / 4), 1 / sqrt(2)) expect_equal(cos(pi / 4), 1 / sqrt(2)) expect_equal(tan(pi / 4), 1) }) # Failing test:
# NOT RUN { test_that("trigonometric functions match identities", { expect_equal(sin(pi / 4), 1) }) # }