A brief overview of tinytest
Package setup
A quick way to set things up is as follows.
tinytest::setup_tinytest("pkgdir")where pkgdir is a package source directory with a valid DESCRIPTION file
The setup is as follows.
- Files with names starting with
testare inpkg/inst/tinytest, e.g.test_haha.R. Test files are R scripts interspersed with test commands, such asexpect_equal(0, myfunc(1)). tinytestis addedSuggests:in theDESCRIPTIONfile.- A file named
tinytest.Ris set up inpkg/teststo make sure that tests
will be run by R CMD check.
Interactive package testing
| Function | description |
|---|---|
test_all("pkgdir") | run all test files (pkg must be loaded). |
build_install_test("pkgdir") | build, install, and test in temp dir. |
run_test_dir("pkgdir") | run all test files in a directory (pkg must be loaded). |
run_test_file("testfile") | run a single test file (pkg must be loaded). |
All functions return an object of class tinytests. Results can be printed to
screen, summarized with summary or converted to data frame with
as.data.frame for analyses. The option verbose (default: TRUE) toggles
between showing test progress in the terminal.
Test functions
The syntax of test functions resembles that of testthat. For expectations comparing two results, the first argument represents the observed value while the second argument represents the desired value.
| Function | description |
|---|---|
expect_true | Argument must evaluate to TRUE |
expect_false | Argument must evaluate to FALSE |
expect_equal | Data and attributes of arguments must be equal |
expect_equivalent | Data of arguments must be equal |
expect_identical | Target and current mustbe identical |
expect_warning | Expression must yield a warning |
expect_error | Expression must yield an error |
For tests in a script there is an alternative syntax in the style of
RUnit. For each function of the
form expect_lol there is a function of the form checkLol.
Print options
Test results (objects of class tinytests) have two printing modes: a long
format and a short, one-line format. Information that is always shown includes:
- File name and line number of failed test.
- The test call that resulted in test failure.
- The type of failure. This can be 'data' (for differences in variable content), 'attr' (for differences in attributes like column names), or 'xcpt' for exceptions (warnings, errors).
In long format, the test call and difference between desired and realized input
are shown in full. Global printing options can be set with options(option=value).
| Option | default | description |
|---|---|---|
tt.pr.passes | FALSE | print passing tests? |
tt.pr.limit | 10 | how many results to print? |
tt.pr.nlong | 3 | how many tests in long format? |
tt.pr.color | TRUE | print colored output? |
It is also possible to influence these options using print.tinytest.
Run tests for an installed package
For a package called haha that is tested with tinytest, any user that has
haha and tinytest installed can run tests as follows.
library(haha)
library(tinytest)
run_test_dir( system.file("tinytest",package="haha") )Skipping or ignoring tests
Use ignore(testfunction) to run a test but not include the result in the output.
# both tests run, but only second is recorded.
if ( ignore(expect_equal)(2, 1+1) ){
expect_true( 1 > 0 )
}Note the placement of brackets.
Use at_home() to detect whether a test is running interactively, or via
test_package() (i.e. the way R CMD check will run it).
if ( at_home() ){
# run tests requiring lots of time.
}Comparing with data stored on file
Data can be loaded from pkg/inst/tinytest (or subdirectories). A simple
test file might look like this.
desired <- read.csv("mycsvoutput.csv", stringsAsFactors=FALSE)
obtained <- compute_my_result()
expect_equal(obtained, desired)If you wish to publish the package on CRAN, make sure that the files are small enough for the package to be acceptable. See the cran repository policy for explicit bounds on package size. Alternatively you can avoid installing the data and associated test files by adding them to .Rbuildignore.
More information
See the vignette.
vignette("using_tinytest", package="tinytest")