R code coverage for the testthat package

Question

Is there any tools to evaluate code coverage for R scripts using the testthat package? I found nothing by Google except a mention of the topic in the Future work section of an RJournal article.

Answer 1

There is the newly-arrived covr package which seems to do everything you want, and more! It provides integration with various CI services and shiny. It works with any kind of testing infrastructure (testthat, RUnit, anything else) and also works with compiled code.

---

What follows is just a very simple demo case I compiled quickly to get you started.

install.packages("covr")

Add a file testcovr/R/doublefun.r containing

doublefun <- function(x, superfluous_option) {
    if (superfluous_option) {
        2*x
    } else {
        3*x
    }
}

and a file testcovr/tests/testthat/test.doublefun.r containing

context("doublefun")

test_that("doublefun doubles correctly", {

    expect_equal(doublefun(1, TRUE), 2)
})

and then run e.g.

test("testcovr")
## Testing testcovr
## doublefun : .

library(covr)
package_coverage("testcovr")
## doublefun : .
##
## Package Coverage: 66.67%
## R/doublefun.r: 66.67%
zero_coverage(package_coverage("testcovr"))
## doublefun : .
##
##        filename first_line last_line first_column last_column value
## 3 R/doublefun.r          5         5            9          11     0

Answer 2

You can use the following solution to evaluate code coverage for R scripts using the testthat package:

library(covr)
coverage_to_list()