How to run a package's testthat tests

Question

For a given installed package, how do I run its testthat tests? I'm not a developer of the installed package, I'm a user. I just want to run its test suite to confirm its tests pass in my environment. I've tried test_check and test_package but I see errors.

To be more specific, I know its test suite fails and I want to run the tests in an interactive R session so I can debug it.

> require(eplusr)    # choice of package unimportant. Any using testthat will do.
Loading required package: eplusr
> require(testthat)
Loading required package: testthat
> test_check("eplusr")
Error in test_files(paths, reporter = reporter, env = env, stop_on_failure = stop_on_failure,  : 
  No matching test file in dir
> test_package("eplusr")
Error: No tests found for eplusr


> sessionInfo()
R version 3.5.1 (2018-07-02)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Ubuntu 18.04.1 LTS

Matrix products: default
BLAS: /usr/lib/x86_64-linux-gnu/openblas/libblas.so.3
LAPACK: /usr/lib/x86_64-linux-gnu/libopenblasp-r0.2.20.so

locale:
 [1] LC_CTYPE=en_US.UTF-8       LC_NUMERIC=C               LC_TIME=en_US.UTF-8        LC_COLLATE=en_US.UTF-8     LC_MONETARY=en_US.UTF-8    LC_MESSAGES=en_US.UTF-8    LC_PAPER=en_US.UTF-8      
 [8] LC_NAME=C                  LC_ADDRESS=C               LC_TELEPHONE=C             LC_MEASUREMENT=en_US.UTF-8 LC_IDENTIFICATION=C       

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] testthat_2.0.0 eplusr_0.9.1  

loaded via a namespace (and not attached):
 [1] Rcpp_0.12.18      magrittr_1.5      units_0.6-0       hms_0.4.2         progress_1.2.0    uuid_0.1-2        bit_1.1-14        debugme_1.1.0     R6_2.2.2          rlang_0.2.2      
[11] stringr_1.3.1     blob_1.1.1        tools_3.5.1       data.table_1.11.5 cli_1.0.0         DBI_1.0.0         withr_2.1.2       bit64_0.9-7       assertthat_0.2.0  digest_0.6.16    
[21] tibble_1.4.2      crayon_1.3.4      processx_3.2.0    readr_1.1.1       callr_3.0.0       later_0.7.4       base64enc_0.1-3   ps_1.1.0          fasttime_1.0-2    memoise_1.1.0    
[31] RSQLite_2.1.1     stringi_1.2.4     pillar_1.3.0      compiler_3.5.1    prettyunits_1.0.2 lubridate_1.7.4   pkgconfig_2.0.2  

Answer 1

R doesn't install the testthat tests by default. To do so try :

install.packages('eplusr', INSTALL_opts="--install-tests", type='source')

Then, either:

testthat::test_package('eplusr')

or alternatively using the built-in testInstalledPackage:

tools::testInstalledPackage('eplusr')

Answer 2

You can't (unless you reinstall overriding default behaviour as shown in Brodie's answer).

It's a design flaw^Hchoice. testthat, in all its wisdom, decided to not install tests by default by enforcing the placement in the tests/ directory. R offers an option to override it (as shown) which is generally not turned on. Hence the dilemma.

Of course, RUnit did it correctly all along having tests below inst/. So if a package uses RUnit you can run its tests once installed. Without having to reinstall it.

Edit: 1 1/2 years later, many of us now use the tinytest package which arrived within the last year. Among other advantages, also allows very easy testing of installed packages.