A test encapsulates a series of expectations about a small, self-contained
set of functionality. Each test lives in a file and contains multiple
expectations, like `expect_equal()`

or `expect_error()`

.

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

`test_that(desc, code)`

desc

Test name. Names should be brief, but evocative. They are only used by humans, so do you

code

Test code containing expectations. Braces (`{}`

) should always
be used in order to get accurate location data for test failures.

When run interactively, returns `invisible(TRUE)`

if all tests
pass, otherwise throws an error.

# NOT RUN { 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) }) # } # NOT RUN { test_that("trigonometric functions match identities", { expect_equal(sin(pi / 4), 1) }) # }