testit
A Simple Package for Testing R Packages
Provides two convenience functions assert() and test_pkg() to facilitate testing R packages.
This package provides two simple functions (30 lines of code in total):
-
assert(fact, ...): think of it asmessage(fact)+stopifnot(...) -
test_pkg(package): runs tests with all objects (exported or non-exported) in the package namespace directly available, so no need to usepackage:::namefor non-exported objects
Why?
The reason is laziness. It is tedious to type these commands repeatedly in tests:
message('checking if these numbers are equal...')stopifnot(all.equal(1, 1+1e-10), 10*.1 == 1) message('checking if a non-exported function works...')stopifnot(is.character(package:::utility_foo(x = 'abcd', y = 1:100)))With the two simple functions above, we type six letters (assert) instead
of sixteen (message + stopifnot), and assert is also a more intuitive
function name for testing purposes (you assert a fact followed by evidence):
assert( 'these numbers are equal', all.equal(1, 1+1e-10), 10*.1 == 1) assert( 'a non-exported function works', is.character(utility_foo(x = 'abcd', y = 1:100))) assert('T is TRUE and F is FALSE by default', { (T == TRUE) (F == FALSE)})R CMD check
Put the tests under the directory pkg_name/tests/testit/ (where pkg_name
is the root directory of your package), and write a test-all.R under
pkg_name/tests/:
library(testit)test_pkg('pkg_name')That is all for R CMD check. For package development, it is recommended to
use devtools. In
particular, Ctrl + Shift + L in RStudio makes all objects in a package
visible to you, and you can play with the tests freely.
Installation
Stable version on CRAN:
install.packages('testit')Development version:
devtools::install_github('yihui/testit')More
How about testthat? Well,
this package is far less sophisticated than testthat. There is nothing
fancy in this package. Please do consider testthat if your tests require
more granularity. I myself do not use testthat because I find it unnecessary
to invent a new vocabulary (testthat::expect_xxx), and the error message of
testthat is somehow obscure in my eyes. For testit, I do not need to
think if I should use expect_equal, expect_equivalent, or
expect_identical; I just write test conditions that return TRUE or FALSE. That
is the only single rule to remember.
There is no plan to add new features or reinvent anything in this package. It is an intentionally tiny package.
Although he did not really mean it, Xunzi said something that happens to apply well to unit testing:
This package is free and open source software, licensed under GPL.
News
CHANGES IN testit VERSION 0.8
NEW FEATURES
o When %==% is used inside assert(), a message will be printed if the value
is not TRUE, to show the values of the LHS and RHS, respectively.
CHANGES IN testit VERSION 0.7
NEW FEATURES
o provided an alternative way to write assertions of the form assert('fact', {(condition_2); (condition_2)}); see ?testit::assert for more information
CHANGES IN testit VERSION 0.6
NEW FEATURES
o test_pkg() runs package tests with top-level environment being set to the namespace of the tested package (thanks, @kalibera, #3)
MAJOR CHANGES
o all test scripts (test-*.R) are assumed to be encoded in UTF-8 if they contain multibyte characters
CHANGES IN testit VERSION 0.5
NEW FEATURES
o added an infix operator %==% as an alias of identical() (in RStudio, you
can use an add-in to insert the text %==%)
MINOR CHANGES
o test_pkg() will print out the filename of the R script that errored
CHANGES IN testit VERSION 0.4
MAJOR CHANGES
o the fact argument of assert() is optional now: all arguments of
assert() can be test conditions
CHANGES IN testit VERSION 0.3
MAJOR CHANGES
o the test files have to be named of the form test-.R (or test-.r), i.e. they have to use the prefix test-
o the test environment is always cleaned (all objects removed) before the next test is run
CHANGES IN testit VERSION 0.2.1
MINOR CHANGES
o fixed a test that failed under R 2.15.x because the argument keep.source did not exist in parse()
CHANGES IN testit VERSION 0.2
MAJOR CHANGES
o assert() does not use base::stopifnot() any more; a tailored version of stopifnot() is used now; see ?assert for the differences between this version and base::stopifnot(); in particular, assert(fact, logical(0)) will fail but stopifnot(logical(0)) will not
CHANGES IN testit VERSION 0.1
NEW FEATURES
o this is the first version of testit; the source code is hosted on Github: https://github.com/yihui/testit
o added functions assert(), test_pkg(), has_error() and has_warning()